HTTP Header Builder

Compose cache control, security headers, CORS, compression hints and redirects into a paste-ready block.

Compose response headers

Preset Server format

Cache-Control Security headers CORS

Compression hints Redirect headers Strict transport security

CORS allow-origin Cache seconds

Redirect target

Headers emitted: 0

Format: plain

Cache-Control with immutable suits hashed asset names; HTML documents usually need a much shorter lifetime.

Choose a preset, then tick the header groups you want in the response.
Set the cache lifetime, the CORS origin and the redirect target where they apply.
Pick a server format, click Build headers and copy the block into your configuration.

Common questions about the free online http header builder.

They are metadata lines a server sends before the body, telling clients how to cache, secure, encode and interpret the response.

Choose a preset, tick the groups you need, set the values, pick a server format and click Build headers to copy the result.

Hashed assets can be cached for a year, while HTML documents usually need minutes to hours so updates appear quickly.

The nosniff value stops browsers from guessing a content type, which blocks a common class of script injection attack.

It still protects older browsers. Modern sites can send frame-ancestors in a Content-Security-Policy instead.

Only when browser scripts on another origin must read your responses, such as a separate front end calling a JSON API.

It tells browsers to use HTTPS only for your domain for the stated period, which prevents downgrade and cookie hijacking.

No. Content-Encoding reports what the server already applied, so enable compression in the server itself as well.

It tells caches that the response depends on the encoding request header, so compressed and plain copies are not mixed up.

Yes. The block is assembled in your browser, nothing is uploaded, and the tool is free with no account and no limits.

Last updated: October 10, 2026