Compress image to 100KB
A hard 100KB cap, hit precisely — quality searched first, dimensions reduced only when needed, all on your device.
Drop your image here
or
JPG, PNG, WebP, HEIC, SVG — any size, no upload
🔒 Files never leave your device — everything runs in your browser.
"Maximum file size: 100KB" — the classic upload-portal wall. Job applications, government forms, university admissions, and CMS fields love this exact number, and a phone photo is usually twenty times too big for it. This tool treats 100KB as a promise: it binary-searches the highest JPEG quality that fits, and only if no quality level is small enough does it step the dimensions down — so you keep the most detail the limit physically allows.
The output is JPG, the format every portal accepts. If your image cannot honestly fit in 100KB even at the smallest reasonable size, the tool says so instead of quietly delivering a corrupted or oversize file — and if it already fits, it is returned untouched. Everything runs in your browser: ID photos, signed forms, and documents never touch a server.
How it works
- Drop your file
Any common format, any size. Nothing is uploaded — the tool runs in your browser.
- Choose quality or size
Pick a quality preset, set an exact KB target, or switch the output format — tuned for compress image to 100kb.
- Download
Your converted file is ready on your device — nothing to wait for, nothing to delete from a server.
Frequently asked questions
Will my image still look good at 100KB?
Usually yes — 100KB comfortably holds a sharp photo at typical form-upload dimensions. The tool always tries the highest quality that fits before touching the dimensions, so nothing is thrown away that the limit does not force out.
What if my image can't be squeezed to 100KB?
You get an honest refusal, not a broken file. In practice almost everything fits — the tool can reduce dimensions as far as needed — but if a fit is impossible, it tells you rather than uploading something a portal will reject.
Why does the output come out as JPG?
JPG compresses photographs far smaller than PNG at the same visual quality and is accepted by every uploader, which makes it the right vehicle for a hard KB limit. If the portal demands another format, convert the result afterwards.
Is my file uploaded to a server?
No. ConvertUno runs entirely in your browser on your own device. Your file never leaves your computer or phone — there is no upload at all.
Is it really free, with no watermark?
Yes. Processing happens on your device, so serving you costs us almost nothing — no watermark, no account, no file-size limit, no daily quota.