API Performance Checker
Enter a REST API endpoint to check response time, status, headers, SSL, compression, CORS, caching, and security — with a performance & security score and a response timeline.
A GET request is sent once — nothing is stored.
What we check
10 checks, two scores
Every run measures performance and security signals, then breaks the response time down by phase.
Performance
- Response time
- HTTP status
- Response headers
- Compression
- Cache headers
- Content type
- Redirects
Security
- SSL / TLS
- CORS
- Security headers
Why it matters
Fast, secure APIs are the foundation of every product
Your API's response time and configuration shape the experience of every app that calls it. Here's why it's worth measuring.
Speed drives retention
Slow APIs cascade into slow apps. Shaving hundreds of milliseconds off responses improves every screen that depends on them.
Secure by default
APIs are a prime attack surface. Checking TLS, CORS, and security headers catches misconfigurations before they're exploited.
Catch regressions
A quick recurring test flags a latency spike or a broken cache header right after a deploy — not after users complain.
How it works
From endpoint to optimization plan in seconds
Enter the API endpoint
Paste a public REST API URL and run the test. No sign-up, no keys required.
We send a test request
We measure response time, status, SSL, compression, caching, CORS, and security headers in one pass.
Get performance & security scores
See two scores, a response-time timeline, and a prioritized list of recommendations.
Optimize & re-test
Apply the fixes to your API or gateway, then re-run to confirm the improvement.
FAQ
Frequently asked questions
What does the API performance checker measure?
It measures HTTP response time and status, TLS/SSL setup, gzip/brotli compression, caching headers, CORS configuration, and key security headers — then rolls them into a performance score and a security score with recommendations.
What is a good API response time?
Under ~200 ms is excellent for a lightweight endpoint, 200–500 ms is acceptable for most APIs, and consistently over ~1 second usually points to a slow query, a cold start, or a missing cache layer worth investigating.
Can it test private or authenticated APIs?
The tool tests publicly reachable endpoints with a simple request and no credentials. For APIs behind authentication or a private network, our engineers can run a deeper, authenticated performance and security review.
Is it safe to test my API?
Yes. It sends a single lightweight request to the URL you provide, reads the response metadata, and stores nothing. It doesn't send load or repeated traffic.
Is the API checker free?
Yes, it's completely free with no sign-up, and results are shown for your session only.
Want us to speed up your API?
Our engineers profile, cache, and harden APIs — cutting latency and closing security gaps across your stack, without disrupting your product.