Use this HTTP utility to parse, normalize, or validate a specific protocol field according to the stated syntax before application-level processing.

HTTP status code

Required integer input.

Classify an HTTP response status code into its RFC 9110 1xx–5xx response class. The tool evaluates the supplied inputs together and returns the named outputs below; it does not infer omitted operating conditions or change the units shown.^[1]

Response class

The resulting response class returned as a string.

• HTTP field syntax and semantics depend on the applicable RFC version and context. Robust parsing must handle case rules, optional whitespace, quoted values, repeated fields, ranges, validators, extension methods, malformed input, and security limits without treating validation as authorization.
• Use finite inputs in the displayed units and preserve more precision than the final presentation requires. Independently verify safety-critical, financial, compliance, or production decisions.

Compare behavior with current HTTP specifications and your server framework, reject ambiguous input explicitly, and test boundary and adversarial cases.

• HTTP ETag Parser

  Parse one HTTP entity tag into its weak/strong flag and opaque value; rejects lists and unquoted values.

• HTTP Header Name Normalizer

  Validate an HTTP field name as an RFC token and convert it to lowercase for case-insensitive lookup.

• HTTP Method Validator

  Check whether a case-sensitive HTTP request method is a nonempty RFC token; custom extension methods are allowed.