Best Security APIs in 2026

The top 15 of 61 free Security APIs, ranked by how easy they are to start with (API key, HTTPS, CORS), how reliable they are in our daily health checks, and what developers rate them. Presend API takes the top spot.

Last tested Oct 24, 2026 · Rankings update daily

1
Presend API
Online · 399 ms
Security and developer utility API -- malware, vulnerability, and domain checks, no signup.
- No API key needed
- Fast: 399 ms response
- Callable from the browser (CORS)
- HTTPS
No authHTTPSCORS
2
IPGuardian API
Online · 940 ms
Check IP addresses against 140+ public threat intelligence blocklists.
- No API key needed
- Callable from the browser (CORS)
- HTTPS
No authHTTPSCORS
3
IPLogs API
Online · 762 ms
Free VPN, proxy, Tor and datacenter IP detection. 13 sources, active probing.
- No API key needed
- Callable from the browser (CORS)
- HTTPS
No authHTTPSCORS
4
OSV API
Online · 608 ms
Open source vulnerability database and distributed triage infrastructure.
- No API key needed
- Callable from the browser (CORS)
- HTTPS
No authHTTPSCORS
5
Passwordinator API
Online · 730 ms
Generate random passwords of varying complexities.
- No API key needed
- Callable from the browser (CORS)
- HTTPS
No authHTTPSCORS
6
VPNDetection API
Online · 726 ms
Check whether an IPv4 or IPv6 address belongs to VPN infrastructure, no key needed.
- No API key needed
- Callable from the browser (CORS)
- HTTPS
No authHTTPSCORS
7D
dead-drop API
Online · 688 ms
Ephemeral zero-knowledge encrypted data sharing.
- No API key needed
- Callable from the browser (CORS)
- HTTPS
No authHTTPSCORS
8
URLhaus API
Online · 317 ms
Database of malicious URLs used for malware distribution.
- No API key needed
- Fast: 317 ms response
- HTTPS
No authHTTPSCORS ?
9
CSR.plus API
Online · 1200 ms
Generate certificate signing requests and private keys without OpenSSL.
- No API key needed
- Callable from the browser (CORS)
- HTTPS
No authHTTPSCORS
10
FilterLists API
Online · 1008 ms
Lists of filters for adblockers and firewalls.
- No API key needed
- HTTPS
No authHTTPSCORS ?
11
Microsoft Security Response Center (MSRC) API
Online · 1079 ms
Programmatic interfaces to engage with the Microsoft Security Response Center (MSRC).
- No API key needed
- HTTPS
No authHTTPSCORS ?
12
Mozilla http scanner API
Online · 1126 ms
Mozilla observatory http scanner. A free security API by mozilla.
- No API key needed
- HTTPS
No authHTTPSCORS ?
13
Mozilla tls scanner API
Online · 989 ms
An observatory for TLS configurations, X509 certificates, and more.
- No API key needed
- HTTPS
No authHTTPSCORS ?
14
SSL Labs API
Online · 589 ms
Deep SSL/TLS server analysis with A+ to F grading.
- No API key needed
- HTTPS
No authHTTPSCORS ?
15
UK Police API
Online · 617 ms
UK Police data. A free security API by data.police.uk.
- No API key needed
- HTTPS
No authHTTPSCORS ?

Security APIs compared

Top Security APIs compared
API	API key	HTTPS	CORS	Uptime	Response	Rating
Presend	No	Yes	Yes	Up	399 ms	Not rated
IPGuardian	No	Yes	Yes	Up	940 ms	Not rated
IPLogs	No	Yes	Yes	Up	762 ms	Not rated
OSV	No	Yes	Yes	Up	608 ms	Not rated
Passwordinator	No	Yes	Yes	Up	730 ms	Not rated
VPNDetection	No	Yes	Yes	Up	726 ms	Not rated
dead-drop	No	Yes	Yes	Up	688 ms	Not rated
URLhaus	No	Yes	Unknown	Up	317 ms	Not rated
CSR.plus	No	Yes	Yes	Up	1200 ms	Not rated
FilterLists	No	Yes	Unknown	Up	1008 ms	Not rated

More Security APIs

Best Security API FAQ

What is the best free Security API in 2026?

Based on access, reliability and developer ratings, the top free Security APIs right now are Presend API, IPGuardian API and IPLogs API. Presend API ranks first. Rankings update daily from health checks of all 61 Security APIs in the directory.

What is the best Security API without an API key?

Presend API, IPGuardian API and IPLogs API need no API key, so you can call them without signing up. 25 of the 61 ranked Security APIs are keyless.

Which Security API works from the browser?

Presend API, IPGuardian API and IPLogs API support CORS over HTTPS, so front-end JavaScript can call them directly without a proxy.

How are these APIs ranked?

Each API gets a score from: no API key (+), HTTPS (+), CORS support (+), 30-day uptime and response time from our daily health checks, and ratings from developers on this site. APIs that failed three checks in a row are left out until they recover.