Compress an image to under 20KB
Get a photo under 20KB in your browser. At this size the dimensions have to come down and the tool does that rather than destroying the quality.
KB here means 1,000 bytes, so a file under the number you set is under it whichever convention the form on the other end uses.
Drop JPG, PNG, WebP, HEIC, AVIF, GIF, BMP files here or paste from the clipboard.
Your files are processed on this device. Nothing is uploaded.
Where this limit comes from
Twenty kilobytes is a limit set by software written a long time ago and never revisited. Forum avatars, old bulletin boards, email signature blocks, legacy ticketing systems and a surprising number of internal HR portals still enforce it. It is also the ceiling some government application forms put on a signature scan, as distinct from the photo, which usually gets more room.
What fits in 20 KB
Not a full-resolution photograph and no amount of clever compression changes that. Twenty thousand bytes buys roughly 400 to 600 pixels on the long edge at a quality that still looks deliberate rather than damaged. A signature, a logo, a headshot cropped tight or an avatar all work. A landscape with foliage in it doesn’t, because fine detail is exactly what compression can’t keep.
What to do before you compress
Crop first. At this size every pixel is expensive and a photograph with a lot of background is spending most of its budget on the parts nobody is looking at. A tight crop of a face will survive 20KB at a size where the same photo uncropped wouldn’t.
Then decide what the image actually is. A signature, a stamp, a logo or a screenshot of text isn’t a photograph and saving it as PNG or WebP will usually beat JPG by a wide margin at this size, because those formats compress flat colour properly.
What it’ll look like
Honest expectation: around 500 pixels on the long edge for a normal photo. That is fine for an avatar, a signature field or a thumbnail and visibly soft if anyone opens it full screen. If the form that demanded 20KB also specifies dimensions, set the width cap as well so the two requirements are met together rather than fighting each other.
When a form asks for 20KB
Read the rest of the requirement before compressing. Application portals that cap the size usually also specify dimensions, a format and sometimes a background colour and a file that meets the size limit but not the dimensions gets rejected just the same.
Common questions
Why does the image get smaller in dimensions too?
Because quality alone can’t get a photograph to 20KB without turning it to mush. The tool drops quality to a floor of about 45 and then reduces the dimensions instead, which produces a small sharp image rather than a full-size smeared one. The row under your file tells you exactly what it ended up at.
Can I keep the original dimensions?
Only if the image is simple enough: a logo, a signature, a flat graphic with few colours. For those, try saving as PNG or WebP instead, since flat colour compresses far better losslessly than photographic detail does.
Is 20KB 20,000 bytes or 20,480?
This tool uses 20,000, the decimal figure. That is the safer of the two, because a file under 20,000 bytes is also under 20,480, so it satisfies whichever convention the form on the other end uses. Windows displays the binary figure, which is why a file can look like 19.9KB on your desktop and still pass.
What if I need it even smaller?
Below about 10KB you’re into icon territory and a photograph isn’t the right input any more. Crop tighter, convert a graphic to PNG or SVG or accept a genuinely small image. The tool will tell you when it can’t reach a target rather than handing back something over the limit.
Guides
Compress to a specific size
Each of these opens the tool with the target already set.