HTTP Header Parser Guide
Turn a pasted header block into a clean table, including cookies and repeated fields.
HTTP headers are lines of information that travel with a request or response. A line has a name, a colon, and a value. HTTP Header Parser separates a pasted block into rows so you can read it without overlooking repeated names.
Read a harmless example
Paste this into Raw header block:
HTTP/1.1 200 OK
Content-Type: application/json
X-Demo: one
X-Demo: two
Under Summary, you should see the status line and Headers: 3. The first line is not counted as a header; the other three lines are. Under Headers, it keeps both X-Demo values; the second name is marked (repeated). This is useful because repeated headers are not always safe to merge.
The tool does not contact the URL or server that produced a block. It only reads what you paste.
Check before pasting real headers
A block from a browser or curl may include Authorization, cookies, or internal hostnames. Remove secrets before putting it in a screenshot or sending it to someone else. This page parses locally, but copying its visible result into a ticket can still disclose that data. A line without a colon is marked unrecognised instead of being guessed.
Where your input goes
Processing runs in your browser. The tool does not upload your input to ilham.dev.
Related guide
For more background, read HTTP and API Debugging.
Questions you might have
- Why are some headers marked as repeated?
- Because the same field name appears more than once. Some headers, like Set-Cookie, are supposed to repeat and must not be merged; others are combined by the recipient. The label shows you which is which before you act on the values.
- How are folded lines handled?
- Older systems wrapped long header values onto the next line with leading whitespace. The parser treats a line that starts with a space or tab as a continuation of the previous header and joins it back with a single space, which is what the HTTP rules say to do.
- What is the status line?
- The HTTP/1.1 200 OK line that opens a response. It is optional here, so you can paste just the headers, but when it is present it is reported separately and not mistaken for a header.
- Is anything sent over the network?
- No. The text you paste is parsed in the page. That is deliberate: header blocks often carry cookies, tokens and internal hostnames that should not leave your machine.