UtilityNest

Compress Image to 20KB

Get a photo or scanned signature under 20 KB in one step, at the exact pixel size your exam or job form asks for. The file is checked against both ways of counting a kilobyte.

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  • Files stay on your device
  • No sign-up
  • Free, no limits

Tip: you can also paste an image with Ctrl+V (Cmd+V on Mac).

KB

Files will be at most 20,000 bytes.

KB

For forms that say e.g. "between 20 KB and 50 KB". Counted as 1 KB = 1024 bytes so it passes both ways.

JPG is what most application forms ask for.

Recommended. The file stays under the limit whether the form counts 1,000 or 1,024 bytes per KB.

KB vs KiB: some sites count 1 KB as 1,000 bytes, others (and Windows) as 1,024. In Safe mode a "20 KB" file is at most 20,000 bytes, so it passes either check. Quality is tuned first; the pixel size is reduced only when the image would otherwise need heavy compression.

Making a passport or visa photo? The Passport Photo Maker crops to the right size with a head guide and makes a printable sheet.

How to use Compress Image to 20KB

  1. 1Drop your photo or signature scan into the box (JPG, PNG, WebP or iPhone HEIC). You can add several files at once.
  2. 2Keep the maximum at 20 KB. If the form also names a minimum, such as 10 KB, type it into Minimum size.
  3. 3If the form names pixel dimensions, turn on Set exact pixel dimensions and pick 140 x 60 px, 200 x 230 px or type your own.
  4. 4Check the preview, file size and dimensions, then click Download, or Download all as a ZIP for a batch.

Signatures and exam forms: the usual 20 KB cases

20 KB is the most common upper limit for signature uploads on recruitment and exam portals, and a frequent limit for small photos. A typical instruction reads like "signature: 140 x 60 pixels, 10 KB to 20 KB, JPG" (the IBPS bank exam format) or "photo: 200 x 230 pixels, 20 KB to 50 KB". Those are examples, not rules for every form, so always copy the numbers from your own notice.

For a signature, sign in black or dark blue ink on plain white paper, take a straight, well-lit photo, then crop it close to the ink before you compress. With Set exact pixel dimensions on, choose Fit with white border if your crop is not exactly the right shape, so no part of the signature is cut off.

Why a file can be too small, and how the minimum works

A 140 x 60 signature on white paper often comes out at only 4 to 8 KB, even at the highest quality, and the form then rejects it as below 10 KB. Type the form's minimum into Minimum size and the tool first raises the quality to 100%. If the file is still too small, it can pad the JPG by adding empty space to the file's comment field. Image viewers and upload checkers ignore that field, so the picture is exactly the same; only the byte count goes up. You can switch padding off.

The minimum is counted as 1 KB = 1,024 bytes, and the maximum in Safe mode as 1 KB = 1,000 bytes, so a file that says "between 10 and 20 KB" passes whichever way the site counts.

How the 20 KB target is reached

The tool binary-searches the JPG quality to find the highest quality that still fits. Large phone photos are first scaled down to a sensible pixel size, because a 12-megapixel picture cannot fit in 20 KB at any readable quality. When you set exact dimensions, the size is never changed and only the quality moves. Everything happens in your browser; your signature and photo are never uploaded.

Frequently asked questions

How do I reduce a signature to under 20 KB?

Drop the signature scan here, keep the target at 20 KB, turn on exact pixel dimensions if your form gives a size such as 140 x 60, and download the JPG. The result shows the exact byte count so you can check it before uploading.

My form says between 10 KB and 20 KB. Can this tool hit that range?

Yes. Enter 10 in Minimum size. If the image is naturally smaller than 10 KB, the tool raises the quality and, if needed, pads the JPG with an empty comment block so it lands inside the range without changing the picture.

Is 20 KB counted as 20,000 or 20,480 bytes?

It depends on the website. In Safe mode the tool keeps the file at or below 20,000 bytes, which is also under 20,480, so it passes either check.

Will my photo look blurry at 20 KB?

A small photo such as 200 x 230 pixels looks clean at 20 KB. A full-size phone photo has to be scaled down a lot to fit, so set the dimensions your form asks for rather than uploading a huge picture.

Can I compress several photos to 20 KB at once?

Yes. Add up to 50 images, and each one is compressed to the same target. Use Download all to save them in one ZIP file.