image/jpegimage/jpeg is the media type for raster images lossily compressed with JPEG (Joint Photographic Experts Group). It compresses photographs and continuous-tone images excellently and is the most widely used photo format on the web.
JPEG uses DCT-based lossy compression, trading file size against image quality via a quality setting. It has no transparency (alpha channel), and it produces ringing artifacts on text, sharp edges, and flat graphics, so PNG or SVG is better for logos and icons. Progressive JPEG sharpens gradually from a low-resolution pass, improving perceived loading.
As already-compressed binary, re-applying gzip at the HTTP transport layer yields almost nothing. Instead, a common pattern negotiates via `Accept: image/webp,image/avif` to prefer more efficient modern formats with JPEG as fallback. EXIF metadata can embed GPS location and capture details, so strip it to avoid privacy leaks on public uploads.
e.g. Content-Type: image/jpeg