Compress an image to 100 KB
Reduce any photo to under 100 KB in your browser. Finds the best quality that fits the limit. No uploads, no sign-up, no watermark.
Drop an image to compress it under 100 KB
or click to browse · paste with Ctrl+V · files never leave your device
Nothing queued yet. Add as many files as you like — everything runs on your own device.
Nothing is uploaded
Conversion runs in your browser. Your files never touch a server, so there is no copy of them to leak.
No sign-up, no watermark
No account, no email, no daily limit, and nothing stamped across your image.
Batch and folders
Drop a hundred files at once and download the results as a single ZIP.
Works offline
Once this page has loaded you can disconnect entirely and it still works.
This tool shrinks an image until it fits inside 100 KB, then stops — keeping as much quality as that budget allows. One hundred kilobytes is the most commonly imposed upload limit on the web: job portals, visa applications, exam registrations and school admission forms nearly all settle on this number.
Everything happens inside this page. Your image is never uploaded, which matters more than usual here, because the files people compress to a fixed size are so often passports, signatures, certificates and identity documents.
How the size search works
Image compressors do not take a file size as input. They take a quality number between 1 and 100, and the file size that comes out the other end depends on the picture itself — a photo of a busy street compresses very differently from a photo of a clear sky. That is why setting "quality 60" and hoping is such an unreliable way to hit a limit.
This tool encodes your image repeatedly and narrows in with a binary search: it tries the middle of the range, sees whether the result is above or below your target, and halves the search space each time. After six to nine encodes it has found the highest quality setting that still fits inside your limit. On a typical photograph the whole process finishes in a fraction of a second, because the encoding runs on your own processor rather than waiting in a queue on somebody's server.
If the smallest possible quality still overshoots — which happens when a very large image is pushed towards a very small limit — the tool switches to reducing the dimensions instead, and tells you it did so. Given the choice between a smeared 4000-pixel image and a clean 800-pixel one at the same file size, the clean one is almost always the better answer.
Getting a good result at a small size
- Crop before you compress. Every pixel you remove is a pixel the compressor no longer has to spend bits on. Cropping to just the subject is the single most effective thing you can do.
- Match the dimensions to the use. A passport photo displayed at 413x531 does not need to be 4000 pixels wide. Resizing first frees the whole budget for the pixels that remain.
- Use JPG for photographs. PNG is lossless and will not shrink meaningfully. If your file is a photo and the form accepts JPG, use it.
- Keep PNG for text and screenshots. Sharp black-on-white text develops ugly halos under aggressive JPG compression. If the form allows PNG, screenshots belong there.
- Do not compress twice. Compressing an already-compressed JPG loses more each time. Go back to the original if you still have it.
Your files stay on your device
The images people compress to a fixed size are rarely casual: passport photographs, signatures, bank statements, medical certificates, exam admit cards. Those are exactly the files you should be most reluctant to upload to an anonymous website.
Nothing here is uploaded. The compression runs in your browser using the same encoders your browser uses to save images, so your document never leaves the machine you are sitting at. Open the Network tab in your developer tools and watch — you will not see your file go anywhere, because there is nowhere for it to go.
Frequently asked questions
How do I compress an image to exactly 100 KB?
Drop your image above. The tool encodes it repeatedly at different quality settings, using a binary search to land on the highest quality that still fits inside 100 KB. That usually takes six to nine attempts and finishes in well under a second — you get the best-looking file that meets the limit, not an arbitrarily crushed one.
Will my photo still look acceptable at 100 KB?
For a portrait or document scan at typical upload dimensions, yes. Trouble starts when a very large image is forced into a very small budget: a 12-megapixel photo squeezed into 100 KB has roughly a hundredth of a bit per pixel to work with. In that case let the tool reduce the dimensions as well — a sharp 800-pixel-wide image at 100 KB looks far better than a smeared 4000-pixel one.
Why does the result come out slightly under 100 KB rather than exactly 100 KB?
Compressors do not accept a size as input, only a quality setting, and the relationship between the two is not linear. We search for the largest file that stays under your limit, so the result lands just below it. Being a few kilobytes under is exactly what an upload form wants — landing exactly on the boundary risks a rejection from a system using a stricter comparison.
Does compressing to 100 KB change the image dimensions?
Not unless it has to. Quality is reduced first, because upload forms usually care about file size while humans care about dimensions. Only when even the lowest quality overshoots 100 KB does the tool start scaling the image down, and it tells you when that happened.
Which format compresses smallest?
JPG is the safest choice for photographs and the format upload forms expect. WebP is roughly a third smaller again at the same quality, and AVIF smaller still, but many forms reject both. If a form has a 100 KB limit and no stated format, use JPG.