Compress Image to 20 KB — Free, In Your Browser

Target size is already set to 20 KB. Add one image or a whole batch, press Reduce Size, and download — every step runs on your own device.

Select images to compress to 20 KB (multiple allowed)

Compressing an image to 20 KB, without uploading it anywhere

20 KB is one of the tightest caps you will ever be asked to hit, and it is almost always a signature rather than a photograph. A phone camera shot of a signature on white paper routinely leaves the camera at 2–4 MB — roughly 150× too big — so the portal rejects it before you even reach the next field. This page presets the compressor to a 20 KB ceiling: drop the file in, hit Reduce Size, and you get back the sharpest JPEG that still fits under 20 KB. Because a signature is high-contrast black ink on white, it survives aggressive compression far better than a photo does, which is exactly why the 20 KB cap is realistic in the first place.

Who needs exactly 20 KB?

A 20 KB limit is not an arbitrary number — it comes from a handful of very specific places. These are the ones people land on this page for:

SSC signature uploads: The Staff Selection Commission asks for a scanned signature in JPEG between roughly 10 KB and 20 KB, at about 140×60 pixels. If your scan lands at 400 KB, the upload silently fails or the form throws a "file size exceeds limit" error.
Indian government job portals: IBPS, RRB, UPSC, state PSC and police recruitment boards all use signature caps in the same 10–20 KB band. The exact number moves per notification, but a file that fits 20 KB clears nearly every one of them.
Favicons and site icons: A 32×32 or 180×180 favicon has no business being larger than 20 KB. Keeping it small means it is fetched on the very first paint instead of competing with your hero image.
Thumbnails and list avatars: Grid and list views load dozens of images at once. At 20 KB apiece, fifty thumbnails cost under 1 MB total — the difference between an instant grid and a visibly stuttering one.

If your form asks for something other than 20 KB, type the exact number into the Target size (KB) field above — it accepts anything from 5 KB to 10 MB.

How it works

JPEG quality and file size are not linearly related, and the curve is different for every image — which is why guessing a quality percentage almost never lands on your target. Instead, this tool binary-searches the JPEG quality scale for the highest quality whose encoded output still fits under 20 KB. Each candidate is encoded for real and measured in bytes, so the answer is exact rather than estimated.

If even the lowest useful quality still overshoots — which happens with very large camera files against a tight target — the tool then downscales the dimensions and searches again, repeating up to four rounds. Downscaling is the last resort, not the first, so you keep as much resolution as the target allows.

All of it runs in your browser. The file is read with the FileReader API, drawn onto an HTML5 canvas, and re-encoded by your own device's JPEG encoder. Nothing is uploaded — there is no server call at any point, no queue, no temporary copy, and no account. Load the page once and you can disconnect from the internet and it still works.

Frequently asked questions

How do I compress an image to exactly 20 KB?

Drop your file on this page and click Reduce Size. The target is already set to 20 KB, so the tool searches for the highest JPEG quality whose output still lands under 20,480 bytes. You get a file at or just under 20 KB rather than exactly 20 KB, which is what upload forms actually check — they enforce a maximum, not an exact match.

Will compressing to 20 KB reduce quality?

For a signature or a line drawing, barely at all — flat white backgrounds and hard black strokes compress extremely efficiently. For a detailed colour photograph, 20 KB is genuinely aggressive and you will see softening and some JPEG blocking. If the portal allows a larger cap for photos, use our 50 KB or 100 KB page instead and save 20 KB for signatures.

Is it safe to compress ID or passport photos online?

With this tool, yes: it never uploads. Your image is read by your own browser, redrawn on an HTML5 canvas, and re-encoded locally by your device. No copy is sent to us or to any third party, there is nothing on a server to leak or subpoena, and it keeps working if you go offline after the page loads.

Other target sizes

Need a different ceiling? Each of these pages opens the same compressor preset to its own target:

Compress image to 50 KB — SSC, UPSC and RRB photo specs.
Compress image to 100 KB — the most common form limit.
Compress image to 200 KB — KYC and ID document scans.
Compress image to 500 KB — email and web performance.
Image size reducer — the full tool, with manual quality control and any custom target you like.

🔎 Verify it yourself: nothing uploads

Don’t take our word for it. Open your browser’s DevTools (F12 → Network tab), then run this tool on any image. You’ll see no upload request at all — your file never leaves this tab. You can even turn off Wi‑Fi once the page has loaded and keep working. Every tool on this site works the same way — all processing happens on your device.