Parser and writer for various spreadsheet formats. Pure-JS cleanroom implementation from official specifications, related documents, and test files. Emphasis on parsing and writing robustness, cross-format feature compatibility with a unified JS representation, and ES3/ES5 browser compatibility back to IE6.

This is the community version. We also offer a pro version with performance enhancements, additional features like styling, and dedicated support.

Pro Version

Commercial Support

Rendered Documentation

In-Browser Demos

Source Code

Issues and Bug Reports

File format support for known spreadsheet data formats:

Browser Test

In the browser, just add a script tag:

<script lang="javascript" src="dist/xlsx.full.min.js"></script>

<script src="https://unpkg.com/xlsx/dist/xlsx.full.min.js"></script>

With npm:

$ npm install xlsx

With bower:

$ bower install js-xlsx

The demos directory includes sample projects for:

Frameworks and APIs

• angularjs
• angular 2 / 4 / 5 / 6 and ionic
• knockout
• meteor
• react and react-native
• vue 2.x and weex
• XMLHttpRequest and fetch
• nodejs server
• databases and key/value stores
• typed arrays and math

Bundlers and Tooling

• browserify
• fusebox
• parcel
• requirejs
• rollup
• systemjs
• typescript
• webpack 2.x

Platforms and Integrations

• electron application
• nw.js application
• Chrome / Chromium extensions
• Adobe ExtendScript
• Headless Browsers
• canvas-datagrid
• Swift JSC and other engines
• "serverless" functions
• internet explorer

<!-- international support from js-codepage -->
<script src="dist/cpexcel.js"></script>

  /* uncomment the lines below to remove support */
  resolve: {
    alias: { "./dist/cpexcel.js": "" } // <-- omit international support
  }

Since the library uses functions like Array#forEach, older browsers require shims to provide missing functions.

To use the shim, add the shim before the script tag that loads xlsx.js:

<!-- add the shim first -->
<script type="text/javascript" src="shim.min.js"></script>
<!-- after the shim is referenced, add the library -->
<script type="text/javascript" src="xlsx.full.min.js"></script>

The script also includes IE_LoadFile and IE_SaveFile for loading and saving files in Internet Explorer versions 6-9. The xlsx.extendscript.js script bundles the shim in a format suitable for Photoshop and other Adobe products.

For parsing, the first step is to read the file. This involves acquiring the data and feeding it into the library. Here are a few common scenarios:

if(typeof require !== 'undefined') XLSX = require('xlsx');
var workbook = XLSX.readFile('test.xlsx');
/* DO SOMETHING WITH workbook HERE */

#include "xlsx.extendscript.js"
/* Read test.xlsx from the Documents folder */
var workbook = XLSX.readFile(Folder.myDocuments + '/' + 'test.xlsx');
/* DO SOMETHING WITH workbook HERE */

var workbook = XLSX.utils.table_to_book(document.getElementById('tableau'));
/* DO SOMETHING WITH workbook HERE */

/* create new workbook */
var workbook = XLSX.utils.book_new();

/* convert table 'table1' to worksheet named "Sheet1" */
var ws1 = XLSX.utils.table_to_sheet(document.getElementById('table1'));
XLSX.utils.book_append_sheet(workbook, ws1, "Sheet1");

/* convert table 'table2' to worksheet named "Sheet2" */
var ws2 = XLSX.utils.table_to_sheet(document.getElementById('table2'));
XLSX.utils.book_append_sheet(workbook, ws2, "Sheet2");

/* workbook now has 2 worksheets */

var htmlstr = document.getElementById('tableau').outerHTML;
var workbook = XLSX.read(htmlstr, {type:'string'});

var url = "http://oss.sheetjs.com/test_files/formula_stress_test.xlsx";

/* set up async GET request */
var req = new XMLHttpRequest();
req.open("GET", url, true);
req.responseType = "arraybuffer";

req.onload = function(e) {
  var data = new Uint8Array(req.response);
  var workbook = XLSX.read(data, {type:"array"});

  /* DO SOMETHING WITH workbook HERE */
}

req.send();

function handleDrop(e) {
  e.stopPropagation(); e.preventDefault();
  var files = e.dataTransfer.files, f = files[0];
  var reader = new FileReader();
  reader.onload = function(e) {
    var data = new Uint8Array(e.target.result);
    var workbook = XLSX.read(data, {type: 'array'});

    /* DO SOMETHING WITH workbook HERE */
  };
  reader.readAsArrayBuffer(f);
}
drop_dom_element.addEventListener('drop', handleDrop, false);

function handleFile(e) {
  var files = e.target.files, f = files[0];
  var reader = new FileReader();
  reader.onload = function(e) {
    var data = new Uint8Array(e.target.result);
    var workbook = XLSX.read(data, {type: 'array'});

    /* DO SOMETHING WITH workbook HERE */
  };
  reader.readAsArrayBuffer(f);
}
input_dom_element.addEventListener('change', handleFile, false);

More specialized cases, including mobile app file processing, are covered in the included demos

• http://oss.sheetjs.com/js-xlsx/ HTML5 File API / Base64 Text / Web Workers

Note that older versions of IE do not support HTML5 File API, so the Base64 mode is used for testing.

$ <target_file base64 | pbcopy

> certutil -encode target_file target_file.b64

• http://oss.sheetjs.com/js-xlsx/ajax.html XMLHttpRequest

When dealing with Readable Streams, the easiest approach is to buffer the stream and process the whole thing at the end. This can be done with a temporary file or by explicitly concatenating the stream:

var fs = require('fs');
var XLSX = require('xlsx');
function process_RS(stream/*:ReadStream*/, cb/*:(wb:Workbook)=>void*/)/*:void*/{
  var buffers = [];
  stream.on('data', function(data) { buffers.push(data); });
  stream.on('end', function() {
    var buffer = Buffer.concat(buffers);
    var workbook = XLSX.read(buffer, {type:"buffer"});

    /* DO SOMETHING WITH workbook IN THE CALLBACK */
    cb(workbook);
  });
}

var fs = require('fs'), tempfile = require('tempfile');
var XLSX = require('xlsx');
function process_RS(stream/*:ReadStream*/, cb/*:(wb:Workbook)=>void*/)/*:void*/{
  var fname = tempfile('.sheetjs');
  console.log(fname);
  var ostream = fs.createWriteStream(fname);
  stream.pipe(ostream);
  ostream.on('finish', function() {
    var workbook = XLSX.readFile(fname);
    fs.unlinkSync(fname);

    /* DO SOMETHING WITH workbook IN THE CALLBACK */
    cb(workbook);
  });
}

The full object format is described later in this README.

var first_sheet_name = workbook.SheetNames[0];
var address_of_cell = 'A1';

/* Get worksheet */
var worksheet = workbook.Sheets[first_sheet_name];

/* Find desired cell */
var desired_cell = worksheet[address_of_cell];

/* Get the value */
var desired_value = (desired_cell ? desired_cell.v : undefined);

var ws_name = "SheetJS";

/* make worksheet */
var ws_data = [
  [ "S", "h", "e", "e", "t", "J", "S" ],
  [  1 ,  2 ,  3 ,  4 ,  5 ]
];
var ws = XLSX.utils.aoa_to_sheet(ws_data);

/* Add the worksheet to the workbook */
XLSX.utils.book_append_sheet(wb, ws, ws_name);

/* create a new blank workbook */
var wb = XLSX.utils.book_new();

• http://sheetjs.com/demos/modify.html read + modify + write files

• https://github.com/SheetJS/js-xlsx/blob/master/bin/xlsx.njs node

The node version installs a command line tool xlsx which can read spreadsheet files and output the contents in various formats. The source is available at xlsx.njs in the bin directory.

Some helper functions in XLSX.utils generate different views of the sheets:

• XLSX.utils.sheet_to_csv generates CSV
• XLSX.utils.sheet_to_txt generates UTF16 Formatted Text
• XLSX.utils.sheet_to_html generates HTML
• XLSX.utils.sheet_to_json generates an array of objects
• XLSX.utils.sheet_to_formulae generates a list of formulae

For writing, the first step is to generate output data. The helper functions write and writeFile will produce the data in various formats suitable for dissemination. The second step is to actual share the data with the end point. Assuming workbook is a workbook object:

if(typeof require !== 'undefined') XLSX = require('xlsx');
/* output format determined by filename */
XLSX.writeFile(workbook, 'out.xlsb');
/* at this point, out.xlsb is a file that you can distribute */

#include "xlsx.extendscript.js"
/* output format determined by filename */
XLSX.writeFile(workbook, 'out.xlsx');
/* at this point, out.xlsx is a file that you can distribute */

var worksheet = workbook.Sheets[workbook.SheetNames[0]];
var container = document.getElementById('tableau');
container.innerHTML = XLSX.utils.sheet_to_html(worksheet);

/* in this example, send a base64 string to the server */
var wopts = { bookType:'xlsx', bookSST:false, type:'base64' };

var wbout = XLSX.write(workbook,wopts);

var req = new XMLHttpRequest();
req.open("POST", "/upload", true);
var formdata = new FormData();
formdata.append('file', 'test.xlsx'); // <-- server expects `file` to hold name
formdata.append('data', wbout); // <-- `data` holds the base64-encoded data
req.send(formdata);

/* output format determined by filename */
XLSX.writeFile(workbook, 'out.xlsb');
/* at this point, out.xlsb will have been downloaded */

/* bookType can be any supported output type */
var wopts = { bookType:'xlsx', bookSST:false, type:'array' };

var wbout = XLSX.write(workbook,wopts);

/* the saveAs call downloads a file on the local machine */
saveAs(new Blob([wbout],{type:"application/octet-stream"}), "test.xlsx");

Downloadify.create(id,{
	/* other options are required! read the downloadify docs for more info */
	filename: "test.xlsx",
	data: function() { return XLSX.write(wb, {bookType:"xlsx", type:'base64'}); },
	append: false,
	dataType: 'base64'
});

The included demos cover mobile apps and other special deployments.

• http://sheetjs.com/demos/table.html exporting an HTML table
• http://sheetjs.com/demos/writexlsx.html generates a simple file

The streaming write functions are available in the XLSX.stream object. They take the same arguments as the normal write functions but return a Readable Stream. They are only exposed in NodeJS.

• XLSX.stream.to_csv is the streaming version of XLSX.utils.sheet_to_csv.
• XLSX.stream.to_html is the streaming version of XLSX.utils.sheet_to_html.
• XLSX.stream.to_json is the streaming version of XLSX.utils.sheet_to_json.

var output_file_name = "out.csv";
var stream = XLSX.stream.to_csv(worksheet);
stream.pipe(fs.createWriteStream(output_file_name));

/* to_json returns an object-mode stream */
var stream = XLSX.stream.to_json(worksheet, {raw:true});

/* the following stream converts JS objects to text via JSON.stringify */
var conv = new Transform({writableObjectMode:true});
conv._transform = function(obj, e, cb){ cb(null, JSON.stringify(obj) + "\n"); };

stream.pipe(conv); conv.pipe(process.stdout);

https://github.com/sheetjs/sheetaki pipes write streams to nodejs response.

XLSX is the exposed variable in the browser and the exported node variable

XLSX.version is the version of the library (added by the build script).

XLSX.SSF is an embedded version of the format library.

XLSX.read(data, read_opts) attempts to parse data.

XLSX.readFile(filename, read_opts) attempts to read filename and parse.

Parse options are described in the Parsing Options section.

XLSX.write(wb, write_opts) attempts to write the workbook wb

XLSX.writeFile(wb, filename, write_opts) attempts to write wb to filename. In browser-based environments, it will attempt to force a client-side download.

XLSX.writeFileAsync(filename, wb, o, cb) attempts to write wb to filename. If o is omitted, the writer will use the third argument as the callback.

XLSX.stream contains a set of streaming write functions.

Write options are described in the Writing Options section.

Utilities are available in the XLSX.utils object and are described in the Utility Functions section:

Importing:

• aoa_to_sheet converts an array of arrays of JS data to a worksheet.
• json_to_sheet converts an array of JS objects to a worksheet.
• table_to_sheet converts a DOM TABLE element to a worksheet.
• sheet_add_aoa adds an array of arrays of JS data to an existing worksheet.
• sheet_add_json adds an array of JS objects to an existing worksheet.

Exporting:

• sheet_to_json converts a worksheet object to an array of JSON objects.
• sheet_to_csv generates delimiter-separated-values output.
• sheet_to_txt generates UTF16 formatted text.
• sheet_to_html generates HTML output.
• sheet_to_formulae generates a list of the formulae (with value fallbacks).

Cell and cell address manipulation:

• format_cell generates the text value for a cell (using number formats).
• encode_row / decode_row converts between 0-indexed rows and 1-indexed rows.
• encode_col / decode_col converts between 0-indexed columns and column names.
• encode_cell / decode_cell converts cell addresses.
• encode_range / decode_range converts cell ranges.

js-xlsx conforms to the Common Spreadsheet Format (CSF):

Cell address objects are stored as {c:C, r:R} where C and R are 0-indexed column and row numbers, respectively. For example, the cell address B5 is represented by the object {c:1, r:4}.

Cell range objects are stored as {s:S, e:E} where S is the first cell and E is the last cell in the range. The ranges are inclusive. For example, the range A3:B7 is represented by the object {s:{c:0, r:2}, e:{c:1, r:6}}. Utility functions perform a row-major order walk traversal of a sheet range:

for(var R = range.s.r; R <= range.e.r; ++R) {
  for(var C = range.s.c; C <= range.e.c; ++C) {
    var cell_address = {c:C, r:R};
    /* if an A1-style address is needed, encode the address */
    var cell_ref = XLSX.utils.encode_cell(cell_address);
  }
}

Cell objects are plain JS objects with keys and values following the convention:

Built-in export utilities (such as the CSV exporter) will use the w text if it is available. To change a value, be sure to delete cell.w (or set it to undefined) before attempting to export. The utilities will regenerate the w text from the number format (cell.z) and the raw value if possible.

The actual array formula is stored in the f field of the first cell in the array range. Other cells in the range will omit the f field.

The raw value is stored in the v value property, interpreted based on the t type property. This separation allows for representation of numbers as well as numeric text. There are 6 valid cell types:

Type n is the Number type. This includes all forms of data that Excel stores as numbers, such as dates/times and Boolean fields. Excel exclusively uses data that can be fit in an IEEE754 floating point number, just like JS Number, so the v field holds the raw number. The w field holds formatted text. Dates are stored as numbers by default and converted with XLSX.SSF.parse_date_code.

Type d is the Date type, generated only when the option cellDates is passed. Since JSON does not have a natural Date type, parsers are generally expected to store ISO 8601 Date strings like you would get from date.toISOString(). On the other hand, writers and exporters should be able to handle date strings and JS Date objects. Note that Excel disregards timezone modifiers and treats all dates in the local timezone. The library does not correct for this error.

Type s is the String type. Values are explicitly stored as text. Excel will interpret these cells as "number stored as text". Generated Excel files automatically suppress that class of error, but other formats may elicit errors.

Type z represents blank stub cells. They are generated in cases where cells have no assigned value but hold comments or other metadata. They are ignored by the core library data processing utility functions. By default these cells are not generated; the parser sheetStubs option must be set to true.

!!(((wb.Workbook||{}).WBProps||{}).date1904)

Each key that does not start with ! maps to a cell (using A-1 notation)

sheet[address] returns the cell object for the specified address.

Special sheet keys (accessible as sheet[key], each starting with !):

• sheet['!ref']: A-1 based range representing the sheet range. Functions that work with sheets should use this parameter to determine the range. Cells that are assigned outside of the range are not processed. In particular, when writing a sheet by hand, cells outside of the range are not included

  Functions that handle sheets should test for the presence of !ref field. If the !ref is omitted or is not a valid range, functions are free to treat the sheet as empty or attempt to guess the range. The standard utilities that ship with this library treat sheets as empty (for example, the CSV output is empty string).

  When reading a worksheet with the sheetRows property set, the ref parameter will use the restricted range. The original range is set at ws['!fullref']

• sheet['!margins']: Object representing the page margins. The default values follow Excel's "normal" preset. Excel also has a "wide" and a "narrow" preset but they are stored as raw measurements. The main properties are listed below:

/* Set worksheet sheet to "normal" */
ws["!margins"]={left:0.7, right:0.7, top:0.75,bottom:0.75,header:0.3,footer:0.3}
/* Set worksheet sheet to "wide" */
ws["!margins"]={left:1.0, right:1.0, top:1.0, bottom:1.0, header:0.5,footer:0.5}
/* Set worksheet sheet to "narrow" */
ws["!margins"]={left:0.25,right:0.25,top:0.75,bottom:0.75,header:0.3,footer:0.3}

In addition to the base sheet keys, worksheets also add:

• ws['!cols']: array of column properties objects. Column widths are actually stored in files in a normalized manner, measured in terms of the "Maximum Digit Width" (the largest width of the rendered digits 0-9, in pixels). When parsed, the column objects store the pixel width in the wpx field, character width in the wch field, and the maximum digit width in the MDW field.

• ws['!rows']: array of row properties objects as explained later in the docs. Each row object encodes properties including row height and visibility.

• ws['!merges']: array of range objects corresponding to the merged cells in the worksheet. Plain text formats do not support merge cells. CSV export will write all cells in the merge range if they exist, so be sure that only the first cell (upper-left) in the range is set.

• ws['!protect']: object of write sheet protection properties. The password key specifies the password for formats that support password-protected sheets (XLSX/XLSB/XLS). The writer uses the XOR obfuscation method. The following keys control the sheet protection -- set to false to enable a feature when sheet is locked or set to true to disable a feature:

• ws['!autofilter']: AutoFilter object following the schema:

type AutoFilter = {
  ref:string; // A-1 based range representing the AutoFilter table range
}

Chartsheets are represented as standard sheets. They are distinguished with the !type property set to "chart".

The underlying data and !ref refer to the cached data in the chartsheet. The first row of the chartsheet is the underlying header.

Macrosheets are represented as standard sheets. They are distinguished with the !type property set to "macro".

Dialogsheets are represented as standard sheets. They are distinguished with the !type property set to "dialog".

workbook.SheetNames is an ordered list of the sheets in the workbook

wb.Sheets[sheetname] returns an object representing the worksheet.

wb.Props is an object storing the standard properties. wb.Custprops stores custom properties. Since the XLS standard properties deviate from the XLSX standard, XLS parsing stores core properties in both places.

wb.Workbook stores workbook-level attributes.

The various file formats use different internal names for file properties. The workbook Props object normalizes the names:

For example, to set the workbook title property:

if(!wb.Props) wb.Props = {};
wb.Props.Title = "Insert Title Here";

Custom properties are added in the workbook Custprops object:

if(!wb.Custprops) wb.Custprops = {};
wb.Custprops["Custom Property"] = "Custom Value";

Writers will process the Props key of the options object:

/* force the Author to be "SheetJS" */
XLSX.write(wb, {Props:{Author:"SheetJS"}});

wb.Workbook stores workbook-level attributes.

wb.Workbook.Names is an array of defined name objects which have the keys:

Excel allows two sheet-scoped defined names to share the same name. However, a sheet-scoped name cannot collide with a workbook-scope name. Workbook writers may not enforce this constraint.

wb.Workbook.Views is an array of workbook view objects which have the keys:

wb.Workbook.WBProps holds other workbook properties:

Even for basic features like date storage, the official Excel formats store the same content in different ways. The parsers are expected to convert from the underlying file format representation to the Common Spreadsheet Format. Writers are expected to convert from CSF back to the underlying file format.

The A1-style formula string is stored in the f field. Even though different file formats store the formulae in different ways, the formats are translated. Even though some formats store formulae with a leading equal sign, CSF formulae do not start with =.

{
  "!ref": "A1:A3",
  A1: { t:'n', v:1 },
  A2: { t:'n', v:2 },
  A3: { t:'n', v:3, f:'A1+A2' }
}

Shared formulae are decompressed and each cell has the formula corresponding to its cell. Writers generally do not attempt to generate shared formulae.

Cells with formula entries but no value will be serialized in a way that Excel and other spreadsheet tools will recognize. This library will not automatically compute formula results! For example, to compute BESSELJ in a worksheet:

{
  "!ref": "A1:A3",
  A1: { t:'n', v:3.14159 },
  A2: { t:'n', v:2 },
  A3: { t:'n', f:'BESSELJ(A1,A2)' }
}

Array Formulae

Array formulae are stored in the top-left cell of the array block. All cells of an array formula have a F field corresponding to the range. A single-cell formula can be distinguished from a plain formula by the presence of F field.

worksheet['C1'] = { t:'n', f: "SUM(A1:A3*B1:B3)", F:"C1:C1" };

worksheet['D1'] = { t:'n', F:"D1:D3", f:"A1:A3*B1:B3" };
worksheet['D2'] = { t:'n', F:"D1:D3" };
worksheet['D3'] = { t:'n', F:"D1:D3" };

Utilities and writers are expected to check for the presence of a F field and ignore any possible formula element f in cells other than the starting cell. They are not expected to perform validation of the formulae!

The !cols array in each worksheet, if present, is a collection of ColInfo objects which have the following properties:

type ColInfo = {
  /* visibility */
  hidden?: boolean; // if true, the column is hidden

  /* column width is specified in one of the following ways: */
  wpx?:    number;  // width in screen pixels
  width?:  number;  // width in Excel's "Max Digit Width", width*256 is integral
  wch?:    number;  // width in characters

  /* other fields for preserving features from files */
  MDW?:    number;  // Excel's "Max Digit Width" unit, always integral
};

The !rows array in each worksheet, if present, is a collection of RowInfo objects which have the following properties:

type RowInfo = {
  /* visibility */
  hidden?: boolean; // if true, the row is hidden

  /* row height is specified in one of the following ways: */
  hpx?:    number;  // height in screen pixels
  hpt?:    number;  // height in points

  level?:  number;  // 0-indexed outline / group level
};

Note: Excel UI displays the base outline level as 1 and the max level as 8. The level field stores the base outline as 0 and the max level as 7.

The cell.w formatted text for each cell is produced from cell.v and cell.z format. If the format is not specified, the Excel General format is used. The format can either be specified as a string or as an index into the format table. Parsers are expected to populate workbook.SSF with the number format table. Writers are expected to serialize the table.

Custom tools should ensure that the local table has each used format string somewhere in the table. Excel convention mandates that the custom formats start at index 164. The following example creates a custom format from scratch:

var wb = {
  SheetNames: ["Sheet1"],
  Sheets: {
    Sheet1: {
      "!ref":"A1:C1",
      A1: { t:"n", v:10000 },                    // <-- General format
      B1: { t:"n", v:10000, z: "0%" },           // <-- Builtin format
      C1: { t:"n", v:10000, z: "\"T\"\ #0.00" }  // <-- Custom format
    }
  }
}

The rules are slightly different from how Excel displays custom number formats. In particular, literal characters must be wrapped in double quotes or preceded by a backslash. For more info, see the Excel documentation article Create or delete a custom number format or ECMA-376 18.8.31 (Number Formats)

Format 14 (m/d/yy) is localized by Excel: even though the file specifies that number format, it will be drawn differently based on system settings. It makes sense when the producer and consumer of files are in the same locale, but that is not always the case over the Internet. To get around this ambiguity, parse functions accept the dateNF option to override the interpretation of that specific format string.

Hyperlinks are stored in the l key of cell objects. The Target field of the hyperlink object is the target of the link, including the URI fragment. Tooltips are stored in the Tooltip field and are displayed when you move your mouse over the text.

For example, the following snippet creates a link from cell A3 to http://sheetjs.com with the tip "Find us @ SheetJS.com!":

ws['A3'].l = { Target:"http://sheetjs.com", Tooltip:"Find us @ SheetJS.com!" };

Note that Excel does not automatically style hyperlinks -- they will generally be displayed as normal text.

Links where the target is a cell or range or defined name in the same workbook ("Internal Links") are marked with a leading hash character:

ws['A2'].l = { Target:"#E2" }; /* link to cell E2 */

Cell comments are objects stored in the c array of cell objects. The actual contents of the comment are split into blocks based on the comment author. The a field of each comment object is the author of the comment and the t field is the plain text representation.

For example, the following snippet appends a cell comment into cell A1:

if(!ws.A1.c) ws.A1.c = [];
ws.A1.c.push({a:"SheetJS", t:"I'm a little comment, short and stout!"});

Note: XLSB enforces a 54 character limit on the Author name. Names longer than 54 characters may cause issues with other formats.

To mark a comment as normally hidden, set the hidden property:

if(!ws.A1.c) ws.A1.c = [];
ws.A1.c.push({a:"SheetJS", t:"This comment is visible"});

if(!ws.A2.c) ws.A2.c = [];
ws.A2.c.hidden = true;
ws.A2.c.push({a:"SheetJS", t:"This comment will be hidden"});

Excel enables hiding sheets in the lower tab bar. The sheet data is stored in the file but the UI does not readily make it available. Standard hidden sheets are revealed in the "Unhide" menu. Excel also has "very hidden" sheets which cannot be revealed in the menu. It is only accessible in the VB Editor!

The visibility setting is stored in the Hidden property of sheet props array.

> wb.Workbook.Sheets.map(function(x) { return [x.name, x.Hidden] })
[ [ 'Visible', 0 ], [ 'Hidden', 1 ], [ 'VeryHidden', 2 ] ]

> wb.Workbook.Sheets.map(function(x) { return [x.name, !x.Hidden] })
[ [ 'Visible', true ], [ 'Hidden', false ], [ 'VeryHidden', false ] ]

VBA Macros are stored in a special data blob that is exposed in the vbaraw property of the workbook object when the bookVBA option is true. They are supported in XLSM, XLSB, and BIFF8 XLS formats. The supported format writers automatically insert the data blobs if it is present in the workbook and associate with the worksheet names.

function wb_has_macro(wb/*:workbook*/)/*:boolean*/ {
	if(!!wb.vbaraw) return true;
	const sheets = wb.SheetNames.map((n) => wb.Sheets[n]);
	return sheets.some((ws) => !!ws && ws['!type']=='macro');
}

The exported read and readFile functions accept an options argument:

• Even if cellNF is false, formatted text will be generated and saved to .w
• In some cases, sheets may be parsed even if bookSheets is false.
• Excel aggressively tries to interpret values from CSV and other plain text. This leads to surprising behavior! The raw option suppresses value parsing.
• bookSheets and bookProps combine to give both sets of information
• Deps will be an empty object if bookDeps is false
• bookFiles behavior depends on file type:
  • keys array (paths in the ZIP) for ZIP-based formats
  • files hash (mapping paths to objects representing the files) for ZIP
  • cfb object for formats using CFB containers
• sheetRows-1 rows will be generated when looking at the JSON object output (since the header row is counted as a row when parsing the data)
• bookVBA merely exposes the raw VBA CFB object. It does not parse the data. XLSM and XLSB store the VBA CFB object in xl/vbaProject.bin. BIFF8 XLS mixes the VBA entries alongside the core Workbook entry, so the library generates a new XLSB-compatible blob from the XLS CFB container.
• codepage is applied to BIFF2 - BIFF5 files without CodePage records and to CSV files without BOM in type:"binary". BIFF8 XLS always defaults to 1200.
• Currently only XOR encryption is supported. Unsupported error will be thrown for files employing other encryption methods.
• WTF is mainly for development. By default, the parser will suppress read errors on single worksheets, allowing you to read from the worksheets that do parse properly. Setting WTF:1 forces those errors to be thrown.

Strings can be interpreted in multiple ways. The type parameter for read tells the library how to parse the data argument:

var range = XLSX.utils.decode_range(worksheet['!ref']);
var ncols = range.e.c - range.s.c + 1, nrows = range.e.r - range.s.r + 1;

The exported write and writeFile functions accept an options argument:

• bookSST is slower and more memory intensive, but has better compatibility with older versions of iOS Numbers
• The raw data is the only thing guaranteed to be saved. Features not described in this README may not be serialized.
• cellDates only applies to XLSX output and is not guaranteed to work with third-party readers. Excel itself does not usually write cells with type d so non-Excel tools may ignore the data or error in the presence of dates.
• Props is an object mirroring the workbook Props field. See the table from the Workbook File Properties section.
• if specified, the string from themeXLSX will be saved as the primary theme for XLSX/XLSB/XLSM files (to xl/theme/theme1.xml in the ZIP)
• Due to a bug in the program, some features like "Text to Columns" will crash Excel on worksheets where error conditions are ignored. The writer will mark files to ignore the error by default. Set ignoreEC to false to suppress.

For broad compatibility with third-party tools, this library supports many output formats. The specific file type is controlled with bookType option:

• compression only applies to formats with ZIP containers.
• Formats that only support a single sheet require a sheet option specifying the worksheet. If the string is empty, the first worksheet is used.
• writeFile will automatically guess the output file format based on the file extension if bookType is not specified. It will choose the first format in the aforementioned table that matches the extension.

The type argument for write mirrors the type argument for read:

The sheet_to_* functions accept a worksheet and an optional options object.

The *_to_sheet functions accept a data object and an optional options object.

The examples are based on the following worksheet:

XXX| A | B | C | D | E | F | G |
---+---+---+---+---+---+---+---+
 1 | S | h | e | e | t | J | S |
 2 | 1 | 2 | 3 | 4 | 5 | 6 | 7 |
 3 | 2 | 3 | 4 | 5 | 6 | 7 | 8 |

XLSX.utils.aoa_to_sheet takes an array of arrays of JS values and returns a worksheet resembling the input data. Numbers, Booleans and Strings are stored as the corresponding styles. Dates are stored as date or numbers. Array holes and explicit undefined values are skipped. null values may be stubbed. All other values are stored as strings. The function takes an options argument:

var ws = XLSX.utils.aoa_to_sheet([
  "SheetJS".split(""),
  [1,2,3,4,5,6,7],
  [2,3,4,5,6,7,8]
]);

XLSX.utils.sheet_add_aoa takes an array of arrays of JS values and updates an existing worksheet object. It follows the same process as aoa_to_sheet and accepts an options argument:

origin is expected to be one of:

XXX| A | B | C | D | E | F | G |
---+---+---+---+---+---+---+---+
 1 | S | h | e | e | t | J | S |
 2 | 1 | 2 |   |   | 5 | 6 | 7 |
 3 | 2 | 3 |   |   | 6 | 7 | 8 |
 4 | 3 | 4 |   |   | 7 | 8 | 9 |
 5 | 4 | 5 | 6 | 7 | 8 | 9 | 0 |

/* Initial row */
var ws = XLSX.utils.aoa_to_sheet([ "SheetJS".split("") ]);

/* Write data starting at A2 */
XLSX.utils.sheet_add_aoa(ws, [[1,2], [2,3], [3,4]], {origin: "A2"});

/* Write data starting at E2 */
XLSX.utils.sheet_add_aoa(ws, [[5,6,7], [6,7,8], [7,8,9]], {origin:{r:1, c:4}});

/* Append row */
XLSX.utils.sheet_add_aoa(ws, [[4,5,6,7,8,9,0]], {origin: -1});

XLSX.utils.json_to_sheet takes an array of objects and returns a worksheet with automatically-generated "headers" based on the keys of the objects. The default column order is determined by the first appearance of the field using Object.keys, but can be overridden using the options argument:

var ws = XLSX.utils.json_to_sheet([
  { S:1, h:2, e:3, e_1:4, t:5, J:6, S_1:7 },
  { S:2, h:3, e:4, e_1:5, t:6, J:7, S_1:8 }
], {header:["S","h","e","e_1","t","J","S_1"]});

var ws = XLSX.utils.json_to_sheet([
  { A:"S", B:"h", C:"e", D:"e", E:"t", F:"J", G:"S" },
  { A: 1,  B: 2,  C: 3,  D: 4,  E: 5,  F: 6,  G: 7  },
  { A: 2,  B: 3,  C: 4,  D: 5,  E: 6,  F: 7,  G: 8  }
], {header:["A","B","C","D","E","F","G"], skipHeader:true});

XLSX.utils.sheet_add_json takes an array of objects and updates an existing worksheet object. It follows the same process as json_to_sheet and accepts an options argument:

origin is expected to be one of:

XXX| A | B | C | D | E | F | G |
---+---+---+---+---+---+---+---+
 1 | S | h | e | e | t | J | S |
 2 | 1 | 2 |   |   | 5 | 6 | 7 |
 3 | 2 | 3 |   |   | 6 | 7 | 8 |
 4 | 3 | 4 |   |   | 7 | 8 | 9 |
 5 | 4 | 5 | 6 | 7 | 8 | 9 | 0 |

/* Initial row */
var ws = XLSX.utils.json_to_sheet([
  { A: "S", B: "h", C: "e", D: "e", E: "t", F: "J", G: "S" }
], {header: ["A", "B", "C", "D", "E", "F", "G"], skipHeader: true});

/* Write data starting at A2 */
XLSX.utils.sheet_add_json(ws, [
  { A: 1, B: 2 }, { A: 2, B: 3 }, { A: 3, B: 4 }
], {skipHeader: true, origin: "A2"});

/* Write data starting at E2 */
XLSX.utils.sheet_add_json(ws, [
  { A: 5, B: 6, C: 7 }, { A: 6, B: 7, C: 8 }, { A: 7, B: 8, C: 9 }
], {skipHeader: true, origin: { r: 1, c: 4 }, header: [ "A", "B", "C" ]});

/* Append row */
XLSX.utils.sheet_add_json(ws, [
  { A: 4, B: 5, C: 6, D: 7, E: 8, F: 9, G: 0 }
], {header: ["A", "B", "C", "D", "E", "F", "G"], skipHeader: true, origin: -1});

XLSX.utils.table_to_sheet takes a table DOM element and returns a worksheet resembling the input table. Numbers are parsed. All other data will be stored as strings.

XLSX.utils.table_to_book produces a minimal workbook based on the worksheet.

Both functions accept options arguments:

<table id="sheetjs">
<tr><td>S</td><td>h</td><td>e</td><td>e</td><td>t</td><td>J</td><td>S</td></tr>
<tr><td>1</td><td>2</td><td>3</td><td>4</td><td>5</td><td>6</td><td>7</td></tr>
<tr><td>2</td><td>3</td><td>4</td><td>5</td><td>6</td><td>7</td><td>8</td></tr>
</table>

var tbl = document.getElementById('sheetjs');
var wb = XLSX.utils.table_to_book(tbl);

Note: XLSX.read can handle HTML represented as strings.

XLSX.utils.sheet_to_formulae generates an array of commands that represent how a person would enter data into an application. Each entry is of the form A1-cell-address=formula-or-value. String literals are prefixed with a ' in accordance with Excel.

> var o = XLSX.utils.sheet_to_formulae(ws);
> [o[0], o[5], o[10], o[15], o[20]];
[ 'A1=\'S', 'F1=\'J', 'D2=4', 'B3=3', 'G3=8' ]

As an alternative to the writeFile CSV type, XLSX.utils.sheet_to_csv also produces CSV output. The function takes an options argument:

• strip will remove trailing commas from each line under default FS/RS
• blankrows must be set to false to skip blank lines.

> console.log(XLSX.utils.sheet_to_csv(ws));
S,h,e,e,t,J,S
1,2,3,4,5,6,7
2,3,4,5,6,7,8
> console.log(XLSX.utils.sheet_to_csv(ws, {FS:"\t"}));
S	h	e	e	t	J	S
1	2	3	4	5	6	7
2	3	4	5	6	7	8
> console.log(XLSX.utils.sheet_to_csv(ws,{FS:":",RS:"|"}));
S:h:e:e:t:J:S|1:2:3:4:5:6:7|2:3:4:5:6:7:8|

The txt output type uses the tab character as the field separator. If the codepage library is available (included in full distribution but not core), the output will be encoded in CP1200 and the BOM will be prepended.

XLSX.utils.sheet_to_txt takes the same arguments as sheet_to_csv.

As an alternative to the writeFile HTML type, XLSX.utils.sheet_to_html also produces HTML output. The function takes an options argument:

> console.log(XLSX.utils.sheet_to_html(ws));
// ...

XLSX.utils.sheet_to_json generates different types of JS objects. The function takes an options argument:

• raw only affects cells which have a format code (.z) field or a formatted text (.w) field.
• If header is specified, the first row is considered a data row; if header is not specified, the first row is the header row and not considered data.
• When header is not specified, the conversion will automatically disambiguate header entries by affixing _ and a count starting at 1. For example, if three columns have header foo the output fields are foo, foo_1, foo_2
• null values are returned when raw is true but are skipped when false.
• If defval is not specified, null and undefined values are skipped normally. If specified, all null and undefined points will be filled with defval
• When header is 1, the default is to generate blank rows. blankrows must be set to false to skip blank rows.
• When header is not 1, the default is to skip blank rows. blankrows must be true to generate blank rows

range is expected to be one of:

header is expected to be one of:

If header is not 1, the row object will contain the non-enumerable property __rowNum__ that represents the row of the sheet corresponding to the entry.

> XLSX.utils.sheet_to_json(ws);
[ { S: 1, h: 2, e: 3, e_1: 4, t: 5, J: 6, S_1: 7 },
  { S: 2, h: 3, e: 4, e_1: 5, t: 6, J: 7, S_1: 8 } ]

> XLSX.utils.sheet_to_json(ws, {header:"A"});
[ { A: 'S', B: 'h', C: 'e', D: 'e', E: 't', F: 'J', G: 'S' },
  { A: '1', B: '2', C: '3', D: '4', E: '5', F: '6', G: '7' },
  { A: '2', B: '3', C: '4', D: '5', E: '6', F: '7', G: '8' } ]

> XLSX.utils.sheet_to_json(ws, {header:["A","E","I","O","U","6","9"]});
[ { '6': 'J', '9': 'S', A: 'S', E: 'h', I: 'e', O: 'e', U: 't' },
  { '6': '6', '9': '7', A: '1', E: '2', I: '3', O: '4', U: '5' },
  { '6': '7', '9': '8', A: '2', E: '3', I: '4', O: '5', U: '6' } ]

> XLSX.utils.sheet_to_json(ws, {header:1});
[ [ 'S', 'h', 'e', 'e', 't', 'J', 'S' ],
  [ '1', '2', '3', '4', '5', '6', '7' ],
  [ '2', '3', '4', '5', '6', '7', '8' ] ]

> ws['A2'].w = "3";                          // set A2 formatted string value

> XLSX.utils.sheet_to_json(ws, {header:1, raw:false});
[ [ 'S', 'h', 'e', 'e', 't', 'J', 'S' ],
  [ '3', '2', '3', '4', '5', '6', '7' ],     // <-- A2 uses the formatted string
  [ '2', '3', '4', '5', '6', '7', '8' ] ]

> XLSX.utils.sheet_to_json(ws, {header:1});
[ [ 'S', 'h', 'e', 'e', 't', 'J', 'S' ],
  [ 1, 2, 3, 4, 5, 6, 7 ],                   // <-- A2 uses the raw value
  [ 2, 3, 4, 5, 6, 7, 8 ] ]

Despite the library name xlsx, it supports numerous spreadsheet file formats:

Features not supported by a given file format will not be written. Formats with range limits will be silently truncated:

Excel 2003 SpreadsheetML range limits are governed by the version of Excel and are not enforced by the writer.