HTTP headers / response header
Content-Encoding
Content-Encoding: gzip
What it does
Declares how the body bytes are compressed (gzip, br, zstd). The client must decode before parsing.
The gotcha
If you see binary garbage instead of JSON, you almost certainly received a compressed body and skipped decompression.
Debugging headers on a phone
The fastest way to see what Content-Encoding is actually doing is to send the request and read both sides raw — ReqPad shows auto-generated and custom headers for every request, on all six protocols, with history. Related references: status codes · WWW-Authenticate · Transfer-Encoding · ETag · Last-Modified · Expires · Location
Inspect Content-Encoding on a live request.
Build the request, send it, read raw headers and timing — from your iPhone. Free to start.