Compress an Image to 50 KB

The target below is already set to 50 KB. Drop an image in and the highest quality that still fits is chosen for you — in your browser, with no upload.

Target 50 KB about 870 × 655 pixels, enough for a portrait to stay recognisable Nothing uploaded

Drop an image here, or click to browse

JPG, PNG or WebP · processed locally · no size limit

Compressed image preview
Set a size and the quality is chosen for you — the highest that still fits.
80–85 is the sweet spot for photographs. Ignored while a target size is set.
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Compression happens in a canvas element on your device. The file is never transmitted, so there is no upload wait and no size cap.

Why people compress to 50 KB

Fifty kilobytes is the smallest size at which a face still looks like that particular person.

  • ID and passport-style photo uploads
  • Job application portals
  • Product thumbnails in a listing grid
  • Anywhere a form says "under 50 KB" without saying why

What survives at 50 KB?

Fifty kilobytes buys roughly four times the pixels of a 20 KB file for two and a half times the bytes, because compression gets more efficient as the image gets larger. That is the practical reason to ask for 50 KB rather than 20 whenever the form allows it: the jump in quality is larger than the jump in size. Expect around 870 pixels wide, which is enough for a portrait to stay recognisable.

The UK passport rule puts the floor at exactly 50 KB

This is the clearest published example of 50 KB as a minimum. GOV.UK's digital photo rules for a passport application require a file "at least 50KB and no more than 10MB", and separately "at least 600 pixels wide and 750 pixels tall". The gap between those two numbers is enormous — a 200-to-1 range on file size — which tells you what the rule is really for: the floor exists to stop people submitting something so heavily compressed that a face cannot be checked against it.

So if you are preparing a passport or visa photo, do not aim at 50 KB. Aim comfortably above it, keep the pixel dimensions above the stated minimum, and treat 50 KB as the line you must not cross downwards.

Source: GOV.UK — Get a passport photo: digital photos

Why 50 KB is more than twice as good as 20 KB

Compression gets more efficient as an image gets larger, because the cost of describing the structure of the picture is spread over more pixels while the fine detail that is expensive to encode is the part being discarded anyway. The practical consequence is the one stated above: two and a half times the bytes buys roughly four times the pixels.

That non-linearity is worth knowing whenever a form gives you a choice or a range. Moving from 20 KB to 50 KB is the single biggest quality step available anywhere on this scale — larger than 50 to 100, and far larger than 100 to 200.

Identity photos have rules beyond file size

A file that satisfies the size limit can still be rejected. Identity-photo rules typically also govern the expression, the background, head coverings, glasses, shadows and how much of the frame the face fills. None of that is something a compressor can fix, and compressing an otherwise non-compliant photograph only produces a smaller non-compliant photograph. Read the full specification before you optimise the file — the size limit is usually the least demanding part of it.

How the target is reached

Quality is searched before resolution, because losing a little quality is far less noticeable than losing pixels. The tool encodes your image repeatedly, halving the range each time, until it finds the highest quality setting that still lands under 50 KB. Only if even the lowest quality is too large does it begin scaling the image down, and it re-searches quality at every smaller size rather than simply shrinking until it fits.

One format note worth knowing: PNG is lossless, so a quality setting does nothing to it. Hitting a size target with PNG is possible only by reducing dimensions. For photographs, WebP or JPEG will always get you further.

Frequently asked questions

Drop the file into the box above. The target is already set to 50 KB, so the tool searches for the highest quality that still fits and applies it. Nothing is uploaded — the whole thing runs in your browser.

Fifty kilobytes buys roughly four times the pixels of a 20 KB file for two and a half times the bytes, because compression gets more efficient as the image gets larger. That is the practical reason to ask for 50 KB rather than 20 whenever the form allows it: the jump in quality is larger than the jump in size. Expect around 870 pixels wide, which is enough for a portrait to stay recognisable.

At 50 KB you can expect about 870 × 655 pixels, enough for a portrait to stay recognisable. The tool always exhausts the quality range before it reduces resolution, so it gives up as little as the target allows.

WebP produces the smallest file at a given quality and is supported by every current browser. Choose JPEG if something specifically requires it, such as an older upload form. PNG is lossless, so a size target can only be met by reducing dimensions — avoid it for photographs.

No. Compression happens in a canvas element on your own device, so the file never leaves your computer. That also means there is no upload wait and no size cap.