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Compress an image to under 50 KB

Get a photo or signature scan under 50 KB for strict application portals.

How it works

50 KB is one of the strictest limits you will meet online. It is common on exam registration portals and public-sector forms, often with separate rules such as "photo between 20 KB and 50 KB" or "signature under 20 KB". A phone photo is a hundred times larger than that, so quality alone rarely gets there: the picture must also be shrunk to a few hundred pixels wide.

This tool does both automatically. It first finds the best quality that fits at the current dimensions, and if 40% quality is still too big it reduces the pixel size in 10% steps until the file is under 50 KB. For a passport-style photo this typically ends around 400 to 600 px, which is exactly what those portals expect. If the form also specifies pixel dimensions, use the image resizer first, then compress.

What the 50 KB compressor did to real files

Measured on 2026-09-22 with this page's own compressor in Chrome. The test files were an A4 page of printed text scanned at 300 dpi (2480 × 3508 px, 2.0 MB JPG), a 12-megapixel photo-like image (4032 × 3024 px, 2.1 MB; a sample photograph enlarged with camera-like noise added) and a 1200 × 1406 px portrait photo (328 KB). JPEG quality is estimated from each output file's quantisation tables.

Every file had to be made smaller in pixels as well as in quality: 50 KB leaves roughly 0.4 megapixels at the lowest quality the tool accepts. On the text page, body text of about 10 points was still readable, but anything smaller softened into grey. That is why 50 KB limits usually belong to photo and signature fields, not to document uploads.

For a passport-style photo the result is a little over 700 px wide, which is more than such fields display. If the form states pixel dimensions too, set them first with the image resizer; a smaller image then keeps a higher JPEG quality at the same 50 KB.

Test fileResultPixel sizeJPEG quality
A4 text page, 300 dpi49 KB630 × 892 (about 76 dpi)about 40
12 MP photo50 KB831 × 624about 41
Portrait, 1200 × 140649 KB709 × 831about 45

Where 50 KB limits come from, and how to meet them

Very small caps are typical of systems that store a photo and a signature for every applicant, such as recruitment and exam portals. Indian government exam forms are the best-known example; our guide to UPSC and SSC uploads lists the limits published for those exams together with each source, including where third-party summaries disagree about pixel sizes.

  • Signatures: crop tight to the ink and keep the background white; a clean signature scan often fits in 10 to 20 KB without being shrunk.
  • Minimum sizes: some forms also set a floor, such as 20 KB. The tool lands just under the maximum, so a floor only matters if your original is already tiny.
  • KB versus kB: if a form measures 50 KB as 50,000 bytes, set the target to 48 KB to be safe.

How to use it

  1. Drop the photo on the upload area or click to browse. JPG, PNG, WebP, HEIC and GIF are accepted.
  2. The target is already set to 50 KB. Adjust it only if your form quotes a different number.
  3. Keep JPG as the output unless the destination explicitly accepts WebP.
  4. Click Compress and wait a second or two; the result card shows the exact output size.
  5. Click Download. The compressed file is saved next to your original, which is not changed.

Frequently asked questions

The form wants 20-50 KB. What if the result is too small?

The tool aims just under the target, so a 50 KB target usually produces 45-50 KB. If you get a result far below the minimum, your image was already tiny; in that case set a slightly higher quality by using the general image compressor in quality mode.

How do I get a signature under 20 KB?

Type 20 in the target box. Scanned signatures compress very well because they are mostly white, so the tool usually keeps the full resolution.

Does the result stay under the limit exactly?

Yes. The output is always at or below the number shown, measured in kilobytes of 1024 bytes, which is also how Windows, macOS and most upload forms measure files. The final size is displayed before you download.

Will my photo look bad?

Quality is only reduced as far as needed. The tool starts from 95% quality and searches downwards; dimensions are only reduced if quality alone cannot reach the target. A JPG or WebP that is already under the limit is returned as it is, never re-encoded into a bigger file. Photos for forms are usually viewed small, so even aggressive targets look fine on screen.

Is the image uploaded to a server?

No. Decoding and encoding happen in a Web Worker inside your browser. The site never receives the file.

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