Compress an image to 20 KB
Application portals often want a signature or ID photo under 20 KB. Drop your image in and Asset Compressor shrinks it below the limit at the best quality that still fits.
- No upload
- Free, no sign-up
- Whole folders
- Works offline
Drop images or a folder here
JPG, PNG, WebP, AVIF or BMP · no file limit
Processed on your device. Nothing is uploaded.
How to reduce an image to 20 KB
- 1
Add your photo or signature
Drop a scan, a phone photo or a screenshot onto the tool. You can add several files at once, for example a photo and a signature.
- 2
Keep the 20 KB target
The target is already set to 20 KB and the image is limited to 640 px on its longest side, which is what makes such a small file possible.
- 3
Match the portal’s pixel size
If the form asks for exact dimensions, such as 200 × 230 px, enter them as the maximum width and height in the settings and apply again.
- 4
Download and upload
Download the JPEG and upload it. The new file size is shown next to each image so you can check it first.
Why 20 KB is a common limit
Exam boards, job portals, scholarship and government sites receive millions of uploads, so they keep files tiny. Many ask for a signature of 10–20 KB and a photo of 20–50 KB. Always read the exact rules on the page you are uploading to: some also set a minimum size, a file type (almost always JPG/JPEG) and pixel dimensions.
20 KB is 20 × 1024 = 20,480 bytes. Asset Compressor uses the same 1 KB = 1024 bytes definition as most upload forms, so a file it reports as 19.8 KB will be accepted by a 20 KB limit.
How it fits a photo into 20 KB
Two things decide the file size of a JPEG: how many pixels it has and how strongly it is compressed. A 12-megapixel phone photo cannot reach 20 KB through compression alone without turning into blocks, so this page first scales the image down to 640 px, then searches for the highest JPEG quality that stays under 20 KB.
That search tries quality levels one after another and keeps the best result that fits, so you never have to guess a quality number or compress the same image again and again.
Tips for signatures and ID photos
For a signature, sign with a dark pen on plain white paper, photograph it in good light and crop tightly around the ink – empty paper still costs bytes. A clean, high-contrast signature looks sharp even at a very small file size.
For a face photo, use a plain light background and crop to head and shoulders. Busy backgrounds and noise from dim lighting take up most of a 20 KB budget, so a simple photo comes out much clearer.
Frequently asked questions
Why is my image still slightly over 20 KB?
Very detailed or noisy images may not fit even at the lowest quality. Lower the maximum width to 400–500 px in the settings, crop away empty areas, and apply again.
Can I compress a signature to 10 KB?
Yes. Change the target size to 10 KB. Signatures are simple images, so they usually stay perfectly readable at 10 KB, especially when cropped tightly.
Will the photo still be clear enough?
At 20 KB the photo is small but clear on screen, which is all an application form needs. Starting from a well-lit, in-focus photo makes the biggest difference.
Can I keep it as PNG?
PNG is lossless, so it can’t be squeezed to an exact size. Most portals ask for JPG anyway, which is why JPEG is the default here.
Related tools
Compress to 50 KB
A 50 KB limit is the most common rule for application photos. Asset Compressor resizes and compresses your picture so it lands just under 50 KB while looking as good as possible.
Compress to 100 KB
Upload forms often demand images under a size limit. Set a target and Asset Compressor finds the highest quality that fits – for every image in the batch.
Crop image
Draw the exact area you want to keep, or crop a whole batch to one shape in a single pass. Your photos are cropped on your own device and never uploaded.
Black & White
Transform your photos into classic monochrome or high-contrast black and white. Drop a single picture or a whole folder – everything is processed in your browser.
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