# How to reduce image size for online forms

Updated 2026-11-08

Government, exam and job portals reject photos over 20, 50 or 100 KB. How to meet the limit in KB and pixels without a blurry result, step by step on a phone.

The form says photo 20 to 50 KB, signature 10 to 20 KB, JPG only, 200 by 230 pixels. Your phone photo is 3 MB and 4000 pixels wide. Every upload fails. This is the most common reason people search for an image compressor, and the fix takes a minute once you know which number means what.

A file has two sizes: the pixel dimensions (width by height) and the file size in kilobytes. Portals usually set both. The trick is to get the dimensions right first, then let the compressor find the quality that fits the kilobyte limit.

## Step 1: read the requirement properly

KB is file size. Pixels are dimensions. cm or inches at a dpi are print dimensions, which convert to pixels: 3.5 × 4.5 cm at 300 dpi is 413 × 531 pixels; at 200 dpi it is 276 × 354. JPG or JPEG means the same thing. A range such as 20 to 50 KB means both ends are enforced, so aim near the top, at 45 KB.

## Step 2: crop before you compress

Open the photo in your gallery and crop it to the face and shoulders for a photo, or tightly around the ink for a signature. Cropping removes most of the bytes at no cost in quality and gets the aspect ratio close to what the form wants.

## Step 3: compress to the limit

1. Open the image compressor, or go straight to the 20 KB, 50 KB or 100 KB page, which opens with the limit set.
2. If the form fixes the pixel size, set Max side to the longer pixel dimension, for example 230 for a 200 × 230 photo.
3. Choose To a target size, type the KB limit, drop the photo and press Compress. The tool lowers JPEG quality first and reduces pixels only if it has to.
4. Check the size shown under the result, then download. The file is a JPG, which every portal accepts.

## Signatures: the 10 to 20 KB window

Sign on white paper with a black or dark blue pen, photograph it in daylight, crop tightly and compress to 20 KB. If the result is under 10 KB, raise the target to 15 and compress the original again. Signatures are mostly white, so they compress well and rarely need shrinking.

## Why uploads still fail, and how to fix each one

Wrong format: the portal wants JPG and you uploaded PNG or HEIC; target-size mode always writes JPG. Wrong dimensions: set Max side to the required number. Too small: some forms set a minimum; compress to a target inside the range instead of as small as possible. File name: a few portals reject spaces or non-Latin letters in file names; rename the file to photo.jpg.

## Questions

### How do I make a photo exactly 50 KB?

Exactness is not needed. Portals check that the file is under the limit, sometimes also over a minimum. Compress to 45 KB for a 20 to 50 KB range.

### Will a 20 KB photo be too blurry?

At 200 × 230 pixels a face is perfectly clear at 20 KB. Blur only appears when a large photo is squeezed without first reducing its pixel dimensions, which the tool does automatically.

### Can I do this on my phone?

Yes. Everything runs in the phone's browser, works offline after loading, and the photo never leaves your device.

### The portal says 3.5 × 4.5 cm. What do I enter?

That is a print size. At 300 dpi it is 413 × 531 pixels; set Max side to 531. At 200 dpi it is 276 × 354.

## Tools used in this guide

- [Image compressor](https://toolovi.com/en/tools/image-compressor/index.md)

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