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Compress an image to under 100 KB

Shrink a photo to under 100 KB for online forms, job portals and ID uploads.

How it works

100 KB is the most common photo limit on online application forms: university admissions, job portals, e-visa systems and many banking KYC uploads use it. The limit exists because those systems store millions of applicant photos and only display them at small sizes.

A modern phone photo is 3 to 8 MB, so it needs a 30 to 80 times reduction. At 100 KB a JPG can still be around 1000 px wide at decent quality, which is more than enough for an ID photo. The tool finds the highest quality that fits and only reduces dimensions when it has to.

What the 100 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.

At 100 KB the portrait lost only a tenth of its width, and the 12 MP photo came out at about 1.2 megapixels, plenty for a photo shown at ID-card size. The text page at 116 dpi was comfortably readable on screen, although a printout of it would look soft.

All three results sat at a JPEG quality in the 40s. That is visible if you zoom in on skin or sky, and invisible at the size forms display photos. If the portal allows 200 KB or more, use the larger limit.

Test fileResultPixel sizeJPEG quality
A4 text page, 300 dpi100 KB960 × 1359 (about 116 dpi)about 40
12 MP photo99 KB1265 × 950about 47
Portrait, 1200 × 140698 KB1080 × 1265about 47

Where you meet 100 KB limits

A 100 KB cap is common on application forms that keep a photo per applicant (admissions, job portals, identity checks). It is also a safe way to satisfy a larger official cap. For example, the US visa photo must be a JPEG of 240 KB or less and between 600 × 600 and 1200 × 1200 pixels (US Department of State); a square photo compressed to 100 KB meets the size rule with room to spare, as long as the pixel size is right too.

  • Set the pixel size the form asks for first, then compress; the tool keeps the dimensions whenever quality alone can reach 100 KB.
  • If a form rejects a file of exactly 100 KB, it probably counts 100,000 bytes: target 95 KB.
  • Converting an iPhone HEIC photo happens in the same step; the output is always a JPG unless you choose WebP.

Sources: US Department of State, digital image requirements (checked 2026-09-20)

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 100 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

Will a 100 KB photo be sharp enough for an ID or visa form?

Yes. Most portals display or print the photo at 35 x 45 mm or smaller. A 600 x 800 px JPG at 75% quality is around 80 KB and looks crisp at that size.

My form says "maximum 100 KB" but rejects a 100 KB file. Why?

Some systems count 100 KB as 100,000 bytes rather than 102,400. Set the target to 95 KB to be safe.

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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