AccioPix WhatsApp photo compression lab test, 7 September 2026
https://acciopix.com/blog/stop-whatsapp-compression-wedding-photos

Original: brick-buildings-under-blue-sky-11363655.jpg by Mat Reding, Pexels
(https://www.pexels.com/photo/brick-buildings-under-blue-sky-11363655/), 6240 x 4160.

Files are exactly as received on the second device, not re-saved:
  full-<sender>-standard.jpg   sent in standard quality
  full-<sender>-hd.jpg         sent with HD selected
  sender = android (WhatsApp Android app, first phone), pixel (WhatsApp Android app, Pixel 9a),
           iphone (WhatsApp iOS app), mac (WhatsApp Mac desktop app),
           web (WhatsApp Web in Firefox on Linux)
  Note: full-pixel-hd.jpg and full-android-hd.jpg are byte-identical as received.

results.csv: dimensions, bytes, JPEG quality estimate (IJG formula from the
file's quantization tables), chroma subsampling, EXIF presence, PSNR and SSIM
against the original resized to the received size.
Script: scripts/whatsapp-quality-test.py in the AccioPix repository.
