Processed entirely on your device — nothing is uploaded
How to use the compress image to 15 kb
- 1Drop your image onto the box above — the 15 KB target is already selected.
- 2Leave the output format on the default (JPG) if this is for an upload portal.
- 3Wait a moment while the tool searches for the best quality under the cap.
- 4Check the reported size and dimensions, then download the 15 KB file.
What actually fits in 15 KB
The useful way to read 15 KB is as a pixel allowance. Mid-quality JPEG needs about 1.8 bits per pixel, which makes the allowance roughly 69,750 pixels — a 4:3 frame of around 300 × 230, or roughly 300 × 225 pixels of photograph, and a good deal more of a signature scanned as dark ink on white.
Not a printing size. At 15 KB the file exists to satisfy an upload box, and anything printed larger than a stamp will show it.
Content bends the numbers: a signature or line drawing on plain white paper compresses several times better than a busy photograph, so it fits at 15 KB with dimensions the arithmetic above would call impossible. A crowd scene or foliage goes the other way.
Where the 15 KB limit comes from
Nobody chooses 15 KB for aesthetic reasons — the number comes from the other side of an upload form. The typical reasons people need it: a signature that sits between a 10 KB floor and a 20 KB ceiling, a thumb impression for a recruitment portal, or an icon-sized photo for a low-bandwidth internal system.
15 KB is rarely a cap on its own — it is where you aim when a form demands 10–20 KB and you want to sit comfortably inside the range rather than on its edge.
However the 15 KB cap reached you, the problem has one shape: the file is bigger than the form will take, the error message is unhelpful, and guessing at export settings burns a submission attempt per guess. Naming 15 KB as a target and letting the tool search for it is the mechanism the job actually calls for.
How this tool reaches 15 KB exactly
The compressor binary-searches JPEG quality: encode, measure against 15 KB, halve the range, repeat. Eight rounds land within about one quality point of the largest encode that still fits, and since it all happens in this tab's memory, the search takes well under a second per image.
Quality alone rarely gets a camera image under 15 KB: a 4,000 × 3,000 phone photo overshoots the 69,750-pixel budget even at the quality floor, so the tool rescales it — to roughly 305 × 229 in that case, estimated from how far over the attempt landed — and searches again. The result line shows the final dimensions, so the trade is never silent.
A note on the format selector: for a 15 KB portal upload, stay on JPG — it is what validation scripts expect. WebP's better quality-per-kilobyte only helps where you control the destination.
Because files at 15 KB caps are so often signatures, ID photos and documents: nothing here leaves your device. Decoding, rescaling, the quality search and the final encode all run inside this browser tab — there is no upload and no server-side copy.
Getting the best result at 15 KB
The most valuable 15 KB trick is done before this page: crop hard. Wasting the 69,750-pixel budget on the empty paper around a signature or the wall behind a face is what makes tiny targets look bad; a tight crop redirects every byte to the subject.
Light and contrast beat megapixels at this size. Dark pen on plain white paper, photographed in daylight without shadows, compresses dramatically better than faint pencil on ruled paper — if a portal rejects your 15 KB file on legibility rather than size, re-shoot the original instead of fighting the encoder.
Portals that cap size at 15 KB often cap dimensions too. When yours does, resize to the demanded width and height first, then compress here — in that order the encoder is not fighting excess pixels, and more of the 15 KB goes to quality.
Ranges with a floor as well as a ceiling are the reason this size exists. A file that lands at 9 KB fails a 10–20 KB requirement exactly as surely as one at 21, and "as small as possible" is the instinct that produces the first failure. Aiming at 15 puts you in the middle of the band, where a portal recomputing size in kibibytes rather than kilobytes cannot push you out of it.
Frequently asked questions
How do I compress an image to exactly 15 KB?
Drop the image above — the target is preset to 15 KB on this page. The tool searches out the highest quality that fits under the cap, shrinking dimensions automatically if it must, and reports the final size before you download. No upload, no watermark, no sign-up.
Will my image still look good at 15 KB?
Good enough for its purpose is the honest answer. 15 KB cannot hold fine photographic detail, so expect softness on faces; signatures and line art fare far better. A tight crop beforehand is the biggest quality lever you have.
Why did the dimensions of my image change?
The pixel count exceeded what 15 KB can hold — about 69,750 pixels of ordinary photo. Below that point no quality slider helps, so the tool shrank the dimensions by its estimate and re-ran the search. Nothing changes silently: the output line shows the new size and dimensions.
Is my photo or signature uploaded anywhere?
No — there is no server in the loop. Everything from decode to the final 15 KB encode happens on your own device, which is the point when the image is a signature or an identity document.
The portal wants specific pixel dimensions as well as 15 KB. What order do I do that in?
Resize to the required dimensions first (the Image Resizer linked below does that), then compress the resized file to 15 KB here. In that order the compressor is not fighting excess pixels, so more of the budget goes to quality.
Does this work with PNG and WebP files too?
Yes — PNG, WebP and AVIF are all accepted and re-encoded toward 15 KB. PNGs convert to JPG by default, since lossless PNG cannot hit small byte targets on photographs, and JPG is what upload portals expect anyway.