AlienVault Open Threat Exchange (OTX) vs Google Safe Browsing

Open Threat Exchange is AT&T Cybersecurity's community threat-intelligence platform, now operated under the LevelBlue brand, where contributors publish "pulses" of malicious IPs, domains, hashes, and URLs that anyone can query. A live, unauthenticated GET against its IPv4 general-info endpoint returned a full 200 JSON response, and both that call and its OPTIONS preflight echoed the request's Origin in Access-Control-Allow-Origin, resolving cors to yes; an OTX-API-KEY is still needed for higher rate limits and pulse subscriptions. Signup, the API key, and the community feed itself are all free.

Google Safe Browsing lets clients check URLs against Google's continuously updated lists of malware, phishing, and unwanted-software sites via the v4 threatMatches:find endpoint, the same data that powers warnings in Chrome and Search. A live POST with a syntactically valid but bogus key returned a 400 "API key not valid" error from safebrowsing.googleapis.com, reconfirming API-key auth and HTTPS, and both that call and its OPTIONS preflight echoed the request Origin in Access-Control-Allow-Origin. The API is free for any Google Cloud project under its published quota.