Why phone photos are so big
A phone photo is around 4000 × 3000 pixels, 12 million pixels saved at high quality. A form wants something like 200 × 230, which is 46,000 pixels. Most of the file size comes from pixels the form doesn't want.
The right order: resize, then compress
- Crop to the right shape (for a passport photo, about 3.5 : 4.5).
- Resize to the exact pixels the form asks for. This alone usually brings a photo under 100 KB.
- Then lower the JPEG quality just enough to land inside the KB range. At 200 × 230 pixels, quality 70–90 is usually enough for 20–50 KB and still looks sharp.
Compressing a 4000-pixel photo hard to reach 50 KB, without resizing, is what produces blocky, blurry results.
Hitting a range, not just a maximum
Forms give a minimum too. If the file is under the minimum, don't add noise or enlarge it: add blank padding inside the file instead. ExamPic does both steps automatically. It searches for the highest quality that stays under the maximum, then pads up to the minimum if needed.
Resize to an exact KB rangeQuick reference
A KB on exam portals is 1,024 bytes. Windows shows file sizes this way; some phones show 1 KB = 1,000 bytes, so a file your phone calls "51 KB" may be 49.8 KB to the portal. When you're close to the limit, trust the tool's size check.