HTTP headers parser
Inspect a copied HTTP header block and preserve repeated fields in JSON.
- 1Add input
- 2Adjust settings
- 3Get your result
Tool input and files are processed in this browser without being uploaded.
Before you start
Paste raw request or response headers to inspect every field line in order. Repeated fields, including Set-Cookie, stay separate in the JSON export.
How to use this tool
- Copy the raw header source from a network inspector or log, then paste it or choose a UTF-8 text/log file.
- Check the start line, field counts and repeated-name count. To inspect values within one comma-list field, enter its name; confirm whether any body lines were ignored.
- Parse and inspect the ordered table; copy or download the complete JSON with separate entries for repeated fields.
Supported inputs and limits
Parses one HTTP header section: an optional request/response start line or HTTP/2-style pseudo-fields, followed by up to 1,000 field lines. A blank line ends the section; body lines are counted but ignored.
Field names follow HTTP token syntax. Obsolete folded lines, malformed names, control characters and invalid UTF-8 files are rejected. This is a structural inspector, not a full protocol or security validator.
Optionally split one chosen comma-list field into quoted values. This is not a general field-semantics parser; Set-Cookie is never split.
Input stays in this browser. No URL is fetched and no account is needed.
Worked example
Example input
HTTP/1.1 200 OK Content-Type: application/json Set-Cookie: a=1 Set-Cookie: b=2
Example options
{}Example output
{
"messageType": "response",
"startLine": "HTTP/1.1 200 OK",
"headers": [
{
"name": "content-type",
"originalName": "Content-Type",
"value": "application/json",
"line": 2
},
{
"name": "set-cookie",
"originalName": "Set-Cookie",
"value": "a=1",
"line": 3
},
{
"name": "set-cookie",
"originalName": "Set-Cookie",
"value": "b=2",
"line": 4
}
]
}When something does not work
Paste one raw header section. Use the Network panel’s header source view; remove folded lines or malformed fields and check the indicated line number.
Frequently asked questions
Why are repeated Set-Cookie lines separate?
Set-Cookie cannot safely be combined as a comma-separated list. The export preserves original order, spelling and every value; names also have a lowercase key for lookup.
Can I split quoted values inside a field?
Yes. Enter that field name, such as pp-groups, to get a separate ordered value array. Quoted commas and escaped quotes are kept inside values. The original field lines remain in the export; Set-Cookie is excluded.
Can I paste a whole HTTP message?
Yes, for one message. The first blank line ends the header section and any following nonempty body lines are counted but not parsed. Obsolete folded header lines are rejected.
Does this fetch a URL or show hidden browser cookies?
No. It only parses text you paste or a local UTF-8 file. Browser JavaScript cannot read network Set-Cookie response headers; copy them from a network inspector or server log when you have access.
Documentation & further reading
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