Light, fast, tree-based way to get cities by zipcode and location.

npm install zips

const zips = require("zips");

U.S. postal codes only. For now.

If zipcode is found, returns a place object with zipcode, city, state, lat, long. Returns null if zipcode not found.

Returns the closest place object to the specified coordinates.

zips doesn't load its data until the first time a function is called. The longest loading time I've seen is 100ms. After that, sub-millisecond returns can be expected.

I saw a lot of zip database modules on npm, but I was displeased with three aspects:

• Old data (zips uses US Postcode data from geonames.org, the most up-to-date I could find).
• Huge, raw data (zips' data is pre-processed so it can just load and go).
• List searching (zips organizes its data into trees instead of going down a list until a match is found or a large hash table).

I hope you're happy too.

1. Download US.zip from GeoNames Postcodes Download Server
2. Extract US.txt to root.
3. npm run update.

Last update: 2023-02-03