Compress an Image to 20 KB
Twenty kilobytes is a hard ceiling on a lot of government and exam upload forms. Drop the picture in and the tool finds the largest version that fits underneath it.
Runs on your device — photos are never uploadedDrop your images here
or click to browse — as many as you like
JPG · PNG · WebP · HEIC
75% is the usual sweet spot for photographs. Below about 50 the edges start to smear.
The tool hunts for the quality that lands there. Government forms commonly cap uploads at 500 KB or 1 MB.
JPG opens absolutely everywhere. The safe choice for photos.
Resizing shrinks a file far more than quality does. A phone photo is often 4000 px wide when 1600 would do.
Every image is decoded in memory, so a hundred phone photos at once will strain a phone. Work in batches of a few dozen if it slows down.
How it works
Three steps, no account, and the photos never leave your computer.
Drop the images in
JPG, PNG, WebP or an iPhone HEIC. Several at once is fine — each one is compressed to the same limit independently.
The target is already set to 20 KB
Change it if you need a different number. The tool searches for the largest picture that fits underneath, rather than making you guess at a quality dial.
Save
One at a time, or all together as a ZIP. The result line reports the size it reached and the dimensions it settled on.
Where a 20 KB limit comes from
Exam and recruitment portals
Public-service and university application systems commonly cap the photograph at 20 to 50 KB and the signature lower still, and reject anything over the line without explaining why.
Signature and thumbprint uploads
Small scans that are mostly white. These fit easily at 20 KB, and often look better saved as PNG than as JPG.
Old systems with tight quotas
Internal portals and legacy databases that were sized when storage was expensive and never revisited.
Anything that must load on a bad connection
A 20 KB image arrives almost instantly on a slow mobile network.
What 20 kilobytes actually buys you
Twenty kilobytes is very small, and it is worth being blunt about what that means: a 12-megapixel photograph cannot survive at this size. Something has to go, and the only question is what.
Most tools answer that question by turning the quality down until the number is reached. That is the wrong answer. A twelve-megapixel picture squeezed into 20 KB by quality alone is a mess of grey blocks — technically under the limit, visibly ruined, and still often over it anyway. The same 20 KB spent on a picture 500 pixels wide looks like a photograph.
So this tool spends the budget on fewer, better pixels. It keeps quality high enough to stay recognisable and shrinks the picture until it fits.
What you get back at 20 KB
| Test image (all 4000 × 3000) | Original | At 20 KB |
|---|---|---|
| A portrait on a plain background smooth skin and an even backdrop, which JPEG stores very cheaply | 1.8 MB | 1583 × 1187 |
| A typical phone snapshot sky, buildings, ground texture — the ordinary case | 2.6 MB | 708 × 531 |
| A scanned page of text thousands of hard black-on-white edges, which JPEG handles badly | 1.3 MB | 421 × 316 |
| A dense outdoor scene foliage, fine detail everywhere, the worst case for any compressor | 3.3 MB | 366 × 274 |
Measured by running this tool's own search against four 12-megapixel test images built to bracket the range from very compressible to barely compressible. Your photograph will land somewhere inside it.
Crop before you compress
This is the single most useful thing you can do at this size, and almost nobody does it.
If a form wants a headshot and you upload a photo with your whole body in it, most of your 20 KB is being spent on a wall, a doorway and a jumper. Crop to the head and shoulders first and every one of those bytes goes to the part that matters. The same limit that produced an unusable picture produces a perfectly good one.
Signatures and stamps are a different problem
Forms that ask for a signature under 20 KB are usually asking for something that is nearly all white with a few dark strokes. JPEG is a poor fit for that: it was designed for photographs and puts grey haze around hard edges. If the form accepts PNG, a signature will normally come out both smaller and sharper as a PNG than as a JPEG.
How the tool finds the size
It searches, rather than guessing. Quality is bisected to find the highest setting that still fits, and if no quality setting fits — which is normal at small targets — the picture is scaled down and the search runs again, until the largest version that fits under the limit is found.
That ordering matters. Turning quality to the floor on a full-size image produces something both ugly and, very often, still over the limit. Fewer pixels at a decent quality is the better trade almost every time, and it is the one this tool makes.
If a target genuinely cannot be reached, the result is shown in red with what it missed by, rather than handed back in green as though it had worked.
Nothing is uploaded
The compression happens in your browser, using your own processor. The photograph is never transmitted, which means there is no queue, no file-size ceiling imposed by a server, and no copy of your picture sitting on somebody else's disk afterwards.
It also means the tool works with no connection at all once the page has loaded.
Common questions
Will my photo still be usable at 20 KB?
For a headshot, yes — a few hundred pixels across is enough for a form that will display it small. For a detailed landscape, no: the tool will have to shrink it to something like 370 pixels wide to fit, and detail that small is gone. Crop to the important part first and the result improves dramatically.
Why did my image come back smaller in dimensions?
Because 20 KB is not enough bytes for that many pixels at any usable quality. Reducing the dimensions is what makes the target reachable while keeping the picture recognisable — the alternative is a full-size image made of grey blocks that often still misses the limit.
The form still says my file is too large.
Check whether it wants kilobytes or kibibytes, and whether it also enforces maximum dimensions in pixels. Some forms have both, and only mention one. The longest-side slider in the tool handles the second limit.
Are my photos uploaded anywhere?
No. The compression runs in your browser on your own processor, so the image never leaves the machine. There is no queue, no server-side size ceiling, and no copy left behind afterwards.
Can I compress a batch to 20 KB at once?
Yes. Drop in as many as you like and each is compressed to the same target independently, then saved individually or together as a ZIP.
More tools
Every one of them runs on your device. No uploads, no accounts.