Guides · Updated 17 September 2026 · 3 min read
Reduce a photo to 20 KB, 50 KB or 100 KB
Exam and government portals cap uploads at a few dozen kilobytes. Here is what actually controls JPEG size, and a one-click way to hit the limit.
Three things decide file size
- Pixel dimensions: a 4000 × 3000 phone photo is 12 megapixels; a 413 × 531 form photo is 0.2. Cropping and resizing is the biggest win.
- JPEG quality: going from 100 to 80 roughly halves the size with almost no visible change; below 60 artefacts appear.
- Format: PNG and HEIC are not accepted by most portals and PNG is far larger for photos. Always export JPEG.
The one-click way
For any photo, open Compress in the Images tab, type the KB limit into “Target size”, and download. The tool lowers JPEG quality step by step and, only if that is not enough, shrinks the pixel dimensions in small steps until the file fits.
For a form photo that also needs an exact size, use the ID Photo tool instead: pick the preset for your form, crop, and set “Max file size” under Advanced options. It resizes to the exact pixel size first, then trims quality until the file passes.
If the file is too small
Some portals also enforce a minimum (for example 20 KB). Raise the cap slightly or use a higher DPI in Advanced options; more pixels means a larger file.
Frequently asked questions
Does reducing KB reduce quality?
Slightly, but at the sizes portals require (around 400 × 500 px) a 40 KB JPEG looks identical to the original on screen. Resizing first is what keeps it sharp.