Compress Image to 20 KB: Reduce a photo to under 20 KB automatically, for forms and uploads. Input: Files from your device and values you enter. Output: Results shown on the page and a downloaded file. Privacy: Runs in your browser: inputs and files stay on your device and are not uploaded.
How to compress an image to 20 KB
- Drop your photo or scan on the box above. The target size is already set to 20 KB.
- The compressor tries JPEG quality levels until the file fits under 20 KB at the best possible quality.
- If even low quality is too big, it reduces the pixel dimensions step by step until it fits.
- Download the result, check it, and upload it to your form.
Why forms ask for 20 KB
Upload limits of 20 KB are common on signature and passport photo uploads. Sites set them to keep their servers fast, but phone photos are often 2–5 MB, far over the limit. Simply lowering quality is usually enough: a signature scan at 400 pixels wide easily fits under 20 KB.
Some forms also require exact pixel dimensions, such as 200 × 230 pixels for a photo or 140 × 60 for a signature. Resize to those dimensions first with the image resizer, then compress here. Check the result before uploading: text in scanned documents should still be readable. If it is not, crop away empty margins first, since fewer pixels means more quality within the same size.
Your image never leaves your device; compression runs in the browser.
Example: a camera photo and a passport photo
An 18-megapixel camera photo (2.9 MB, 5184 × 3456 pixels) became 18.9 KB in 2.5 seconds in Chrome on a laptop. To fit, the tool reduced it to 1799 × 1199 pixels, and at 20 KB a picture that large looks visibly soft: an SSIM similarity score of 0.88, where 1 means identical. A 413 × 531 passport-size photo (99 KB) became 19.4 KB at the same 413 × 531 pixels in 0.2 seconds, and still looks close to the original (SSIM 0.95). So if the form names a pixel size, resize to it first, then compress here. All six photos we tried came out under 20 KB.
How it compares with free image compressors
| This tool | TinyPNG (free) | iLoveIMG (free) | |
|---|---|---|---|
| Aim at an exact size in KB | Yes, 20 KB is preset | Not stated | Not stated |
| Images at once | No fixed limit | Up to 20 | Up to 30 per task |
| File size | Your device memory | 5 MB per image | 200 MB per task |
Free limits as published by each service (checked 22 October 2026): TinyPNG, iLoveIMG pricing. They change often; the paid plans lift them.
FAQ
Will my image look worse at 20 KB?
It depends on the size. Small photos and signatures look fine; large photos are reduced in dimensions to fit.
Why is the result slightly smaller than the target?
The tool picks the highest quality that stays under the limit, so the file is usually a few KB below it.
Can I compress a PNG or PDF to this size?
Images, yes: the output is JPEG, which is far smaller than PNG for photos. PDF files are not supported here.
What does KB mean on forms?
Most forms use 1 KB = 1024 bytes, which this tool also uses, so a file it shows as under the limit will be accepted.
How do I reduce a photo to 20 KB without losing quality?
Resize it to the pixel size the form asks for first, then compress it here. A 413 × 531 passport-size photo fits under 20 KB with little visible loss; a full-size phone photo has to lose much more detail to fit.