Free APIs

Free Security APIs

Threat intelligence, scanning and vulnerability data. 6 APIs with a usable free tier, checked on their official docs on 2026-10-08.
6

Scan files, URLs and domains against many engines

Free tier
Public API: 4 requests/minute, 500 requests/day
Auth
API key
Docs
docs

Catch: Non-commercial use only

source

Check and report abusive IP addresses

Free tier
Free plan: 1,000 checks/day
Auth
API key
Docs
docs

Catch: Free plan: limited reports and no blacklist

source

US government CVE vulnerability database

Free tier
Free; 5 requests per 30 seconds, 50 with a key
Auth
No key
Docs
docs

Catch: Request an API key for higher limits

source

Check if a password hash appears in breaches (k-anonymity)

Free tier
Free, no key
Auth
No key
Docs
docs

Catch: Only the Pwned Passwords endpoint is free

Open source vulnerability database

Free tier
Free, no key
Auth
No key
Docs
docs

Catch: Fair use

source

Check URLs against Google's unsafe-site lists

Free tier
Free for non-commercial use
Auth
API key
Docs
docs

Catch: Non-commercial; Web Risk for commercial

FAQ

What is the best free security API?+

VirusTotal API, AbuseIPDB, NVD CVE 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 security API without an API key?+

Yes: NVD CVE API, Pwned Passwords API, OSV.dev 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 · Developer tools · Games & fun