Request
Accept
Tells the server which response formats the client can handle.
Example
Accept: application/json 📡
dev
HTTP Header Reference
Comprehensive HTTP header guide organized by type. Request, response, security, and caching headers with descriptions and examples.
http headershttp header referencerequest headersresponse headershttp header guide
Reference mode
HTTP header reference viewer
Directly fetching arbitrary response headers from browser-only JavaScript is heavily limited by CORS, so this tool focuses on the headers you should recognize, inspect, and copy while debugging requests.
Headers
16
Categories
4
Security headers
4
Request
Authorization
Carries credentials such as Bearer tokens or API keys.
Example
Authorization: Bearer <token> Request
Content-Type
Describes the media type of the request body.
Example
Content-Type: application/json Request
User-Agent
Identifies the client application making the request.
Example
User-Agent: Mozilla/5.0 Response
Content-Length
Reports the size of the response body in bytes.
Example
Content-Length: 2048 Response
Content-Encoding
Shows whether the response is compressed.
Example
Content-Encoding: br Response
Location
Points to the redirect destination for 3xx responses.
Example
Location: https://example.com/login Response
Server
Identifies the server software that handled the response.
Example
Server: cloudflare Security
Strict-Transport-Security
Forces future requests to use HTTPS.
Example
Strict-Transport-Security: max-age=31536000; includeSubDomains Security
Content-Security-Policy
Restricts which resources the browser may load.
Example
Content-Security-Policy: default-src 'self' Security
X-Frame-Options
Controls whether the page can be embedded in a frame.
Example
X-Frame-Options: DENY Security
Referrer-Policy
Defines how much referrer information is sent.
Example
Referrer-Policy: strict-origin-when-cross-origin Caching
Cache-Control
Defines caching behavior for browsers and CDNs.
Example
Cache-Control: public, max-age=3600 Caching
ETag
Provides a version identifier for cache validation.
Example
ETag: "v3-6f2a" Caching
Expires
Sets a fixed expiration date for cached content.
Example
Expires: Wed, 01 Jan 2026 00:00:00 GMT Caching
Last-Modified
Shows when the resource last changed.
Example
Last-Modified: Tue, 09 Jan 2024 15:04:05 GMT No headers matched the current search and category filter.
How to use
How to Use the HTTP Header Reference
- 1 Browse headers by type: Request, Response, Security, and Caching.
- 2 Each header shows its name, description, and example value.
- 3 Click any header name to copy it. Use this as a quick reference when configuring servers.
HTTP headers carry metadata about requests and responses. Understanding them is essential for debugging API issues, configuring security, and optimizing performance.
Security headers like Content-Security-Policy, X-Frame-Options, and Strict-Transport-Security are critical for protecting web applications from common attacks.
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