Free APIs

Free Developer tools APIs

Registries, code hosts and small utility APIs. 13 APIs with a usable free tier, checked on their official docs on 2026-10-08.
13

Repos, issues, pull requests and users

Free tier
Authenticated: 5,000 requests/hour (unauthenticated is lower)
Auth
No key
Docs
docs

Catch: Token needed for higher limits and private data

source

Package metadata and download counts

Free tier
Free, no key
Auth
No key
Docs
docs

Catch: Rate limits apply to downloads API

Package metadata and release files

Free tier
Free, no key
Auth
No key
Docs
docs

Catch: Cached; be gentle

Image metadata, tags and repositories

Free tier
Free; public data readable
Auth
No key
Docs
docs

Catch: Pull rate limits apply to anonymous image pulls

Stack Overflow questions, answers and users

Free tier
Free; default quota 10,000 requests/day with a key
Auth
API key
Docs
docs

Catch: Quota is per IP/app; honor backoff

source

DEV articles, comments and users

Free tier
Free; key for writes
Auth
API key
Docs
docs

Catch: Public reads need no key

Open source package and dependency data

Free tier
Free key; 60 requests/minute
Auth
API key
Docs
docs

Catch: 60 requests/minute

Rust crate metadata

Free tier
Free, no key; 1 request/second
Auth
No key
Docs
docs

Catch: Crawl policy: 1 request/second, set User-Agent

Link previews, screenshots and metadata

Free tier
Free: 50 requests/day
Auth
No key
Docs
docs

Catch: Free tier rate limited

source

Public holidays for 100+ countries

Free tier
Free, no key
Auth
No key
Docs
docs

Catch: Community-run

source

Holidays and observances worldwide

Free tier
Free plan: 500 requests/month
Auth
API key
Docs
docs

Catch: Free plan non-commercial

source

Dozens of small utility APIs (nutrition, jokes, validation)

Free tier
Free tier with monthly call limit
Auth
API key
Docs
docs

Catch: Free tier limits premium endpoints

source

Google and other search results as JSON

Free tier
Free plan: 250 searches/month
Auth
API key
Docs
docs

Catch: Free plan not for commercial use

source

FAQ

What is the best free developer tools API?+

GitHub REST API, npm Registry API, PyPI JSON API are good places to start. Compare the free tiers and catches in the table; they differ mostly in limits and whether commercial use is allowed.

Is there a developer tools API without an API key?+

Yes: GitHub REST API, npm Registry API, PyPI JSON API, Docker Hub API, crates.io API work without a key.

More free APIs: Weather · Maps & geocoding · Finance & crypto · Currency exchange · AI & ML · Email & messaging · IP & geolocation · News & social · Sports · Movies, TV & anime · Music · Books & reference · Space & science · Government & open data · Translation & language · Images & media · Fake data & testing · Food & recipes · Transportation · Health · Security · Games & fun