Font Identification API

Identify fonts from letterform traits or an image, matched against a library of free open-source fonts. Free for humans on this site - this API is for programmatic and bulk use.

Endpoint

POST https://fonts.free/api/identify/

Two modes. Send wizard answers as JSON, or an image as multipart form data. Add ?top=N (1-48) to set how many matches come back.

1. By letterform traits

curl -X POST "https://fonts.free/api/identify/?top=8" \
  -H "Content-Type: application/json" \
  -d '{"answers": {"serif": ["none"], "contrast": ["low"], "a": ["double"]}}'

2. From an image (beta)

curl -X POST "https://fonts.free/api/identify/" \
  -F "image=@sample.png"

Response

{
  "ok": true,
  "mode": "wizard",
  "matches": [
    {"slug": "roboto", "family": "Roboto",
     "url": "https://fonts.free/fonts/roboto/",
     "css": "…", "score": 3}
  ]
}

Authentication and limits

Without a key the endpoint works but is rate-limited per IP - fine for trying it out. A key raises your limit against a monthly quota. Send it as a header or query parameter:

-H "X-Api-Key: your_key"      # or  ?key=your_key

Plans

Free

100 calls / month

No key needed for light use. Great for prototypes and low-volume tools.

Pro

$9/mo - 10,000 calls

For production apps and batch identification. Priority matching.

Business

$49/mo - 100,000 calls

High-throughput or embedded use. Priority matching.

See plans and subscribe

The free tier needs no key - just call the endpoint, it is rate-limited per IP. Subscribe on the pricing page for a key with a higher monthly quota. Every match the API returns is a free, open-licensed font, so there is nothing to license downstream.