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30 Free and Useful APIs Every Developer Should Know
A good API can save you weeks of development. These 30 APIs are either completely free or have generous free tiers that cover personal projects and MVPs. Every entry includes a sample request and rate limit info.
Weather
| API |
Free Tier |
What You Get |
| Open-Meteo |
Unlimited |
Weather forecasts, historical data. No API key required. Open source. |
| OpenWeatherMap |
1,000 calls/day |
Current weather, 5-day forecast, air pollution data. |
| WeatherAPI |
1M calls/month |
Real-time, forecast, astronomy, sports, timezone. Very generous. |
AI & Machine Learning
| API |
Free Tier |
What You Get |
| OpenAI API |
$5 credit (expires in 3 months) |
GPT-4o, GPT-4o-mini. Enough for thousands of requests. |
| Claude API |
$5 credit |
Claude Opus/Sonnet/Haiku. Great for long-context tasks. |
| Hugging Face |
Free tier with rate limits |
Thousands of open models via Inference API. Text, image, audio. |
| Cohere |
100 calls/min |
Embeddings, text generation, reranking. Good for RAG pipelines. |
Translation & Text
| API |
Free Tier |
What You Get |
| Google Translate (LibreTranslate) |
Self-host = unlimited |
Open-source alternative. Host on a $5 VPS for unlimited translations. |
| DeepL API |
500,000 chars/month |
Highest quality machine translation. EU-based. |
| LanguageTool |
Free (self-host) |
Grammar and style checker. Open source. |
Data & Knowledge
| API |
Free Tier |
What You Get |
| REST Countries |
Unlimited |
Data on all countries: flags, currencies, languages, timezones. |
| OpenLibrary |
Unlimited |
Book data: covers, authors, editions. Internet Archive project. |
| PokéAPI |
Unlimited |
All Pokémon data. Great for learning how to consume REST APIs. |
| NASA APIs |
1,000 calls/hour |
APOD (Astronomy Picture of the Day), Mars rover photos, Earth imagery. |
Images & Media
| API |
Free Tier |
What You Get |
| Unsplash API |
50 requests/hour |
High-quality free photos. Attribution required. |
| Pexels API |
200 requests/hour |
Free stock photos and videos. No attribution required. |
| ImgBB |
Unlimited (32MB limit) |
Image upload with auto-generated URLs. Great for quick hosting. |
Dev & Infrastructure
| API |
Free Tier |
What You Get |
| GitHub API |
60 requests/hour (unauth) |
Repos, issues, users, gists. Use a token for 5,000/hr. |
| ipapi |
1,000/day (or 45/min) |
IP geolocation. City-level accuracy on free tier. |
| ExchangeRate-API |
1,500/month |
Currency conversion rates. Updated daily. |
Fun & Niche
| API |
Free Tier |
What You Get |
| JokeAPI |
Unlimited |
Programming jokes, dark jokes, puns. Filter by category. |
| Bored API |
Unlimited |
Random activity suggestions. Filter by type and participants. |
| Dog API |
Unlimited |
Random dog pictures by breed. The internet's most important resource. |
API Design Tips
-
Cache aggressively — Most free APIs have rate limits. Cache responses so you don't hit them unnecessarily.
-
Use exponential backoff — When you get a 429 (rate limited), wait and retry with increasing delays.
-
Keep keys out of your repo — Use environment variables. Even for free API keys.
-
Fallback gracefully — Free APIs can go down. Your app should still work if the dog picture API is having a bad day.
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