I Tested 50+ Free APIs. These 20 Actually Work.
No broken endpoints. No surprise paywalls. No deprecated docs.
Data and Research
| API |
What It Does |
Key? |
Limit |
| OpenAlex |
250M+ papers |
No |
100K/day |
| Crossref |
140M+ DOIs |
No |
50/sec |
| ORCID |
18M researchers |
No |
24/sec |
| Semantic Scholar |
200M papers |
Yes |
100/5min |
| Internet Archive |
800B web pages |
No |
Polite |
| Wikipedia |
60M+ articles |
No |
Polite |
Weather and Geo
| API |
What It Does |
Key? |
Limit |
| Open-Meteo |
Forecast + historical |
No |
10K/day |
| Nominatim |
Geocoding |
No |
1/sec |
| OSRM |
Routing |
No |
Fair use |
| ip-api.com |
IP geolocation |
No |
45/min |
Security
| API |
What It Does |
Key? |
Limit |
| HIBP Passwords |
Breach check |
No |
Unlimited |
| crt.sh |
SSL certs |
No |
Polite |
| Shodan |
Device search |
Yes |
100/mo |
| VirusTotal |
Malware scan |
Yes |
4/min |
Developer Tools
| API |
What It Does |
Key? |
Limit |
| GitHub |
Repos, users |
Yes |
5000/hr |
| npm Registry |
Packages |
No |
Fair use |
| PyPI |
Python pkgs |
No |
Fair use |
| Open Library |
20M+ books |
No |
Fair use |
Dead APIs (Skip These)
- Twitter/X: $100/month minimum
- NewsAPI: free tier = yesterday only
- Google Maps: $200 credit burns fast
- Alpha Vantage: 5 calls/minute = useless
Pattern
Best free APIs come from non-profits (Wikipedia, OSM), academia (OpenAlex, Crossref), and security community (HIBP). Companies always paywall eventually.
GitHub | More articles
More from me: 10 Dev Tools I Use Daily | 77 Scrapers on a Schedule | 150+ Free APIs
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