Compress Image to 20 KB
Get a photo, scanned signature or stamp under 20 KB in a few seconds. The tool searches for the highest JPEG quality that still fits, and works fully offline in your browser.
Kept safely under this size.
🔒 Runs in your browser. Your files and text are not uploaded.
How to use the Compress Image to 20 KB
- Drop your picture on the box, click it to browse, or paste an image from the clipboard. You can add several files at once.
- Leave the target at 20 KB or change it. The tool keeps the file under 20 × 1,000 bytes, so it passes whether a system counts 1 KB as 1,000 or 1,024 bytes.
- Keep the format on JPEG unless the form says otherwise. JPEG is accepted almost everywhere; WebP is smaller but often rejected by forms.
- If your form also gives a minimum such as “between 10 and 20 KB”, aim for the maximum: the tool lands just under 20 KB, which satisfies both ends of the window.
- Look at the size on the result row. Download the file, or collect all of them with “Download all (ZIP)”.
Why 20 KB is a popular limit
Twenty kilobytes is the sweet spot for small ID-style uploads: big enough for a recognisable face at a modest size, small enough to keep old servers happy. You will often see it for signatures (typically with a lower limit still) and small photographs on application forms. It is a limit that most pictures can meet by lowering the pixel size a little and the quality a little, rather than by wrecking either.
What you can expect at 20 KB
| Picture | Pixel size | Typical result |
|---|---|---|
| Signature on white paper | 200 × 80 to 300 × 100 | Well below 20 KB, sharp lines |
| Portrait, plain background | 200 × 230 | About 10–18 KB at good quality |
| Portrait, plain background | 300 × 350 | About 18–30 KB: quality has to drop to around 50–60% |
| Portrait at 35 × 45 mm, 300 dpi | 413 × 531 | Usually needs a size reduction as well as lower quality |
| Photo with a busy background | 300 × 300 | Often over 20 KB until the size is reduced |
The pixel counts are examples, not rules. If a form lists exact dimensions, resize to them with the Resize Image tool and set “Max file size” to 20 there. It keeps your pixel size and lowers quality only.
Photo or signature: different priorities
A signature is dark lines on a white sheet. It tolerates heavy compression, but grey paper or shadows waste bytes and make the strokes look dirty; use the signature tool to whiten the paper and trim the margins, then check the size.
A portrait needs the face to stay clean. Crop so that the head fills most of the frame, use even light, and avoid heavy shadows behind the head. If you need an official layout with a head guide, make the picture with the Passport Photo Maker first and compress afterwards.
Stay within the minimum, too
Some uploaders reject files that are too small, not only too big. A typical window is “20 KB to 50 KB” or “10 KB to 20 KB”. If the tool brings your picture far below the minimum, because the original was tiny or very simple, run it through Increase Image Size in KB, or choose the next target up, Compress Image to 50 KB.
Frequently asked questions
What quality will my photo have at 20 KB?
It depends on the pixel size: a 200 × 230 portrait can keep a good quality, a 300 × 350 one drops to about half. The result row shows the final quality and size in pixels, so you can judge before downloading.
Can I compress several signatures or photos at once?
Yes. Drop them all in; each gets its own row, and “Download all (ZIP)” saves them together.
Does the tool keep my original file?
Yes. It never changes your original; you download a new copy with the target size in its name.
Is 1 KB 1,000 or 1,024 bytes?
It depends on the system: Windows counts 1,024 bytes, macOS and many web forms count 1,000. To be safe, this tool keeps the result below 20 × 1,000 bytes (20,000 bytes), which is under the limit either way.
Do you store or look at my pictures?
No. The picture is processed in your browser, and no file is sent anywhere.