All communication apps these days severely compress the photos that we send to others. I have been trying to get people to send me HD versions of photos on these apps, but even that isn’t a replacement for sending the “original” file via e-mail or Air Drop, if possible. I did a quick comparison of the file sizes and resolutions across multiple apps and variants using a single photo from my camera as the reference.
| Source | File Size | Resolution | Compression |
|---|---|---|---|
| Camera | 10.88 MB | 6000x4000 | 1x |
| WhatsApp - HD | 1.36MB | 4160x2773 | 8x |
| WhatsApp - Normal | 279 KB | 1500x1000 | 38x |
| Signal - HD | 1.70 MB | 4096x2731 | 6.4x |
| Signal - Normal | 508 KB | 2048x1365 | 21x |
The original file size does not seem to matter, because files of any size are compressed to be under 300 KB by WhatsApp. So, the compression ratio will be less for photos taken on smartphones.