api: YAML JSON TOON Database
version: 1.0.0
format: yaml
dataset:
  id: 2817
  slug: http-request-headers
  title: HTTP Request Headers
  description: Common HTTP request headers and their purposes.
  summary: "Common HTTP request headers with a description and an example value: Accept, Accept-Language, Accept-Encoding, Authorization, Cache-Control, Content-Type, Cookie, Host and User-Agent, plus Origin, Referer, Range, conditional headers and proxy headers."
  use_when:
    - You need the purpose and format of a request header.
    - You are debugging a request in browser developer tools.
  caveats:
    - Some headers can be set only by the browser; scripts cannot set forbidden header names.
    - X-Forwarded-For can be spoofed by clients unless a trusted proxy overwrites it.
  related:
    - http-response-headers
    - http-content-negotiation
    - http-authentication-methods
    - http-cors-guide
  entry_count: 20
  fields:
    - section: data
      field: header
      type: string
      example: Accept
    - section: data
      field: description
      type: string
      example: Content types the client can process.
    - section: data
      field: example
      type: string
      example: application/json, text/html
  category: Web Technologies
  category_slug: web-technologies
  tags: web,http,headers,request,api
  view_count: 40
  created_at: 1793403093
  updated_at: 1793403093
data:
  - header: Accept
    description: Content types the client can process.
    example: application/json, text/html
  - header: Accept-Language
    description: Preferred languages for the response.
    example: en-US, en;q=0.9
  - header: Accept-Encoding
    description: Acceptable content encodings.
    example: gzip, deflate, br
  - header: Authorization
    description: Credentials for authentication.
    example: Bearer eyJhbGci...
  - header: Cache-Control
    description: Caching directives for request and response.
    example: no-cache, max-age=3600
  - header: Content-Type
    description: Media type of the request body.
    example: application/json; charset=utf-8
  - header: Content-Length
    description: Size of the request body in bytes.
    example: "1234"
  - header: Cookie
    description: Previously set cookies to send back to the server.
    example: session_id=abc123
  - header: Host
    description: Domain name of the server.
    example: api.example.com
  - header: User-Agent
    description: Client application identifier.
    example: Mozilla/5.0 ...
  - header: X-Request-ID
    description: Custom header for request tracing.
    example: req-abc123def456
  - header: If-None-Match
    description: Conditional request using ETag.
    example: "\"33a64df551425fcc55e4d42a148795d9f25f89d4\""
  - header: Origin
    description: The origin (scheme, host, port) that initiated a cross-origin or POST request.
    example: "https://example.com"
  - header: Referer
    description: The URL of the page that linked to the resource; the misspelling is historical.
    example: "https://example.com/page"
  - header: Range
    description: Asks for only part of a resource, used for resumable downloads and media seeking.
    example: bytes=0-1023
  - header: If-Modified-Since
    description: Conditional request that returns 304 Not Modified if the resource has not changed since the date.
    example: "Wed, 21 Oct 2015 07:28:00 GMT"
  - header: If-Match
    description: Makes a request conditional on the resource's ETag matching, used to avoid lost updates.
    example: "\"33a64df551425fcc\""
  - header: X-Forwarded-For
    description: De facto header listing the originating client IP and proxies a request passed through.
    example: 203.0.113.5, 198.51.100.7
  - header: Forwarded
    description: Standardized header (RFC 7239) carrying proxy information such as the client address and protocol.
    example: for=203.0.113.5;proto=https
  - header: Sec-Fetch-Site
    description: Browser-set header indicating how the request's origin relates to the target, useful for blocking cross-site requests.
    example: same-origin