HTTP Headers Parser
About HTTP Headers Parser
HTTP Headers Parser converts a copied request or response header block into JSON while keeping repeated fields separate and preserving empty values.
How it works
Recognize the message start line
An optional HTTP status line becomes response metadata, while a method, request target and HTTP version become request metadata. Header-only blocks work too.
Preserve repeated fields
Case-insensitive duplicate names are collected into arrays instead of being joined. This is especially important for fields such as Set-Cookie that cannot be safely comma-joined.
Diagnose malformed input
Invalid field names and lines without a colon report their source line. Obsolete folded continuations are unfolded and counted rather than silently discarded.
Frequently asked questions
Are HTTP header names case-sensitive?
No. Duplicate matching is always case-insensitive. Output names can be normalized to lowercase or retain the first spelling encountered.
Does this split comma-separated header values?
No. Comma rules differ by field, so each physical header line is preserved as one value and only repeated lines become arrays.
Does the parser send a request?
No. It only parses pasted text locally and performs no network activity.
Sources & last verified
The behaviour of this tool and the claims on this page were checked against the specifications below on . Everything runs in your browser, so the output you see is exactly what the engine produced.
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