HTTP Header Diff Online Free
Paste two HTTP header sets and see the differences. No uploads.
Headers A
Headers B
How to Diff HTTP Headers
Paste your HTTP header sets into the two boxes above. Click Diff Headers. The tool parses each set and shows added, removed, changed and unchanged header names.
Why Compare HTTP Headers
Comparing headers between environments (staging vs production) helps catch missing security headers, caching misconfigurations and CORS issues before they reach users.
Free SEO Audit Tool checks page speed. SEO Audit Services provides full technical audits.
Frequently Asked Questions
How does HTTP header diff work?
Paste two sets of HTTP headers. The tool parses each into a map and shows added, removed, changed and unchanged header names between them.
Do you upload my headers?
No. All comparison happens in your browser. Your HTTP headers never leave your device.
Can I paste raw response headers?
Yes. Paste headers in Name: Value format, one per line. The tool handles duplicate headers.
What headers should I compare?
Compare security headers (CSP, HSTS, X-Frame-Options), caching headers (Cache-Control, ETag), or any custom headers between environments.
Is there a file size limit?
No. The tool runs entirely in your browser with no uploads.
Can I compare headers from two different URLs?
Yes. Fetch headers from each URL (via curl or DevTools) and paste them here for comparison.