A collection of production-ready Cloudflare Workers for solving common technical SEO problems at the edge — without touching the origin codebase.

Each Worker in this repo is self-contained, deployable on its own, and solves a specific class of SEO problem that would otherwise require a multi-week engineering cycle.

• A domain behind Cloudflare
• A Workers Paid plan ($5/month minimum — you'll almost certainly stay within the included 10M requests)
• Node.js v18 or later
• Basic familiarity with the command line

Clone the repo and pick a Worker to deploy:

git clone https://github.com/nimajafari/edge-seo-workers.git
cd edge-seo-workers/workers/01-redirect-map
npm install
npx wrangler login
npx wrangler deploy

Each Worker folder has its own README.md with specific configuration instructions — things like which URL patterns to route it to, what to edit before deploying, and what gotchas to watch for.

edge-seo-workers/
├── workers/
│   ├── 01-redirect-map/
│   │   ├── README.md       # What it does, how to configure
│   │   ├── wrangler.toml   # Cloudflare deployment config
│   │   └── src/
│   │       └── index.js    # The Worker code
│   ├── 02-canonical-rewriter/
│   └── ...
├── tests/
│   ├── redirect-map.test.js       # Worker 01 (redirect logic, loop prevention)
│   └── canonical-rewriter.test.js # Worker 02 (HTMLRewriter rewrite/inject)
├── vitest.config.js               # Runs tests in the Workers runtime (workerd)
├── .github/workflows/test.yml     # CI: runs the suite on every push / PR
├── package.json
├── LICENSE
└── README.md

Run the suite with:

npm install
npm test

Tests run inside the real Workers runtime via @cloudflare/vitest-pool-workers, so APIs like HTMLRewriter and request.cf behave exactly as they do in production.

If you're an SEO with basic JavaScript chops: pick one Worker, read its README, edit the config variables at the top of src/index.js, and deploy. Each Worker is designed to be understood and modified without deep dev experience.

If you're a developer whose SEO team sent you this: the Workers are deliberately simple so you can harden, test, and compose them into whatever pipeline makes sense for your stack. Several of them are worth combining via Service Bindings.

If you're teaching Edge SEO: the workers/ folder is ordered from easiest (01) to most nuanced (08). Walking through them in order is a reasonable syllabus.

• These are starting points, not drop-in solutions. Your canonical logic, hreflang map, schema generation, and URL patterns are specific to your site. The code here is the scaffolding; the business logic is yours to fill in.
• Test before you deploy broadly. Scope each Worker to a single URL pattern or subdomain first. Cloudflare makes rolling back trivial — use that.
• Log before you transform. The first version of any production Worker should be read-only. Capture traffic, verify assumptions, then turn on mutation.
• Don't cloak. Several of these patterns could be used to serve different content to crawlers vs users. Don't. Google's cloaking policy applies to edge-served content exactly the same as it does to origin-served content.

From the official Workers limits reference:

• CPU time: 30s max on Paid, but aim to stay under 50ms
• Memory: 128MB per isolate
• Subrequests: 50 per invocation
• Bundle size: 10MB compressed
• Startup time: 400ms max for top-level code

• Cloudflare Workers documentation
• HTMLRewriter API reference — the most important API in this repo
• Workers examples gallery — more patterns beyond SEO
• Google Search Central JavaScript SEO basics

MIT. Use these in client work, fork them, modify them, teach from them. Attribution is appreciated but not required.

Pull requests welcome, especially:

• Additional SEO-focused Worker patterns
• Tests for existing Workers
• Better documentation of edge cases

Please keep each Worker self-contained and runnable in isolation — that's the design principle of this repo.