| Requirement | Value |
|---|---|
| Target size | Under 100 KB |
| Pixel size | Unchanged |
| Format | JPG |
100 KB is a comfortable limit. At this size a photograph keeps most of its detail, so this preset leaves the pixel dimensions alone and only reduces the quality.
If the form also specifies a pixel size, open More options and set the width and height. Getting the file size right while the dimensions are wrong still produces a rejection, usually with an unhelpful error message.
Photographs taken against a plain wall in good light compress far better than busy or dim ones — the fine grain in a dark photo is what eats the space.