Compress an image to 20 KB

20 KB is the limit exam boards and government portals set most often for a passport photo or a scanned signature, often with a minimum of 10 KB beside it. A phone photo is two to five megabytes, so it has to lose more than 99 % of its weight, and done by hand that usually means a blocky, unreadable picture.

Here the file comes out under 20 KB every time, and as large and as sharp as 20 KB allows: the quality stays at 72 or more while the picture is reduced, and only a very detailed image goes below that. A typical phone photo ends up about 350 pixels wide; a signature on white keeps far more, because it is saved without colour.

Compress your image to 20 KB

Drop your image here or click to browseSupported: JPG, PNG, WebP, HEIC, AVIF, GIF, BMP, TIFF • Max 100MB

How to get an image under the limit

  1. Upload the photo or the scan: JPG, PNG, WebP, HEIC from an iPhone, and more.
  2. 20 KB is already selected. If the form also says "at least 10 KB", or gives exact dimensions such as 200 × 230 pixels, open More options and type them in.
  3. Press Compress and download the JPG. The page shows its exact size, its dimensions and the quality it was saved at.

What the file will be

  • Under 20 KB whichever way the portal counts a kilobyte (1,000 or 1,024 bytes).
  • Upright, in standard colours, without the location and camera data a phone adds.
  • A greyscale picture, such as a signature on white paper, is saved as greyscale and keeps more detail.
  • A minimum is met by raising the quality, then the dimensions, never by padding the file.

Questions about 20 KB images

Clear enough for a form, yes. The tool keeps the JPEG quality at 72 or above and makes the picture smaller instead, so a face stays sharp at about 300–400 pixels across. A photo full of fine detail, such as foliage, may need a lower quality, and the result page tells you which quality was used.
Yes. Open More options and put 10 in the minimum. If the compressed photo comes out under 10 KB, the tool raises the quality, then the dimensions, until it is between the two.
Under More options, type the width and the height. The photo is cropped from the centre to that shape and then compressed under 20 KB at those dimensions. If the two cannot both be met, the page says so instead of handing you a file that would be refused.
Yes, and it usually comes out well under. A signature in dark ink on white is detected as having no colour and saved in greyscale, which leaves room for more detail. A signature on a transparent background is placed on white, so it stays visible in a JPG.
Each compression uses 3 credits. Without an account you have 50 free credits a month, and a free account has 300. A failed compression uses none.

Other sizes

Compress an image to 50 KBCompress an image to 100 KBCompress an image to 200 KB Any size you choose