How to parse a raw HTTP header block into key/value pairs

1. Paste the headers

   Drop the raw header block into the "Headers" field. The tool accepts what `curl -I` prints — one header per line, `Name: value` form, optional initial `HTTP/1.1 200 OK` status line which gets ignored.

2. Press Run

   Result returns `headers` — an object mapping lowercased header names to values. Header names are case-insensitive per HTTP, so the lowercasing is a normalisation step. Duplicate names are kept by appending (commas inside the value).

3. Common things to look for

   `Content-Type` (with optional charset), `Cache-Control` (max-age, immutable, no-store), `Strict-Transport-Security`, `Content-Security-Policy`, `Set-Cookie` (note: Set-Cookie is the one header where commas can NOT be used to join multiple instances).

4. Tricky `Set-Cookie`

   RFC 7230 says headers with multiple values join with `, ` — except `Set-Cookie`, whose own value can contain commas. If your input has multiple Set-Cookie lines, this tool's naive merge will mangle them. Use raw access (e.g. fetch.headers.getSetCookie) for accuracy.