Are uploaded photos compressed?

No: every photo and video is stored exactly as the guest's phone sent it, in its original format and resolution, with no re-encoding and no resizing, so the ZIP you download holds the full-quality files.

The phone sends each file straight to storage; the server only records that it arrived. For the gallery the phone also makes a small thumbnail, which is what the page shows while scrolling, so the gallery stays fast without touching the original. Tap a photo and the full file opens.

This is the difference from sending photos in a chat app, which usually compresses images heavily and shrinks videos. The limits are per file: 10 MB per photo and, on the paid plan, 200 MB per video.

What you do not get is editing: there are no filters, no cropping and no enhancement. The photo in the gallery is the photo the guest took, which is the point.