Compress an image to 100 KB
Upload limits of 100 KB turn up constantly on application forms and government portals. This opens with that target already set.
Compress an image
Drag an image here, or choose one
JPEG, PNG, WebP, GIF, BMP or AVIF, up to 25.00 MB.
Your image is processed in this browser tab. It is not uploaded.
Why 100 KB specifically
It is one of the most common upload limits in the world, and almost always an arbitrary one. University applications, visa and passport portals, job boards, examination boards and government forms all tend to settle on 100 KB for a photograph or a scanned document, usually for reasons that stopped being technical a decade ago.
The limit is rarely explained, and the form usually rejects the file without telling you how far over you are. The counter above shows the exact byte count so you can see precisely where you stand.
Getting a usable result
- Check the dimensions first. If the form asks for a photo and yours is 4000 pixels wide, resize before compressing. 100 KB spread over fewer pixels looks far better.
- Use JPEG unless told otherwise. It is the format forms are built around.
- Check the exact bytes against whatever the form states, in case it means 100,000 rather than 102,400.
- Look at the result before submitting. The tool reports the size honestly, but only you can judge whether the face in the photograph is still recognisable.
Other targets
The same tool handles 200 KB and 500 KB presets, or any custom figure, on the Image Compressor page. If the dimensions rather than the file size are the problem, use the Image Resizer.
Common questions
- Does 100 KB mean 100,000 bytes or 102,400?
- This is the question that catches people out, and the form you are uploading to rarely says. Celveri treats 1 KB as 1024 bytes, so a 100 KB target means 102,400 bytes, and the exact figure is shown on screen. If your form rejects the file anyway, it is almost certainly counting 1 KB as 1000 bytes and wants 100,000. Set a custom target of 97 KB and you will be under both.
- Will a 100 KB photo still look acceptable?
- It depends far more on the dimensions than on the subject. A passport photo or headshot around 600 by 800 pixels usually looks fine at 100 KB. A full 4000-pixel-wide holiday photo squeezed into the same 100 KB will look soft and blocky, because the same budget is spread over twenty times as many pixels. If the result disappoints, make the image smaller first with the Image Resizer, then compress.
- What if it cannot reach 100 KB?
- Then it says so, and gives you the smallest version it managed rather than pretending it succeeded. This happens with large or very detailed images: fine texture, foliage and noise are expensive to store, and there is a floor below which the current dimensions cannot go. The fix is fewer pixels, not more compression.
- Which format should I choose for a 100 KB target?
- JPEG for photographs, which is what most forms expect. WebP reaches 100 KB at noticeably better quality, but some older upload forms reject it. PNG cannot be aimed at a file size at all, because it is lossless and has no quality dial; if your image is a PNG screenshot, convert it to JPEG here and it will shrink dramatically.
- Is my photo uploaded to a server?
- No. The image is compressed by your own browser and the download comes from the copy made in the tab. That matters more than usual here, because 100 KB limits turn up on applications and identity documents. Nothing you compress reaches Celveri.