The response carries only the byte range you asked for with a Range header, described by Content-Range. This is how resumable downloads and media seeking work.
Verify the range you receive is the range you requested, and that Content-Range agrees with the body length — off-by-one errors here corrupt files silently.
1 endpoint in this playground answers with 206. Every one is free, needs no signup, and can be called from the browser or with curl.
GET https://funapi.dev/api/storage/v1/objects/{key} — Partial content (Object Storage API)All HTTP status codes · All 37 mock REST APIs · Getting started guide