How to Compress an Image to 100 KB (or Any Size)

To get an image under 100 KB, open Compress Image to KB, set Maximum file size to 100, and add the picture. The tool searches for the highest quality that still fits under the limit — only shrinking the dimensions when quality alone isn't enough — and gives you a file that's guaranteed to be under it. The same works for 50 KB, 200 KB, 500 KB or any limit you're given.

Compress to an exact size

1. Open Compress Image to KB.
2. Enter the Maximum file size in KB — for example 100.
3. Choose the Format: JPG (accepted everywhere) or WebP (smaller, for websites).
4. Add your image. It's compressed straight away.
5. Check the result — the new size, dimensions and quality are shown — and download it.

Why it's always under the limit

"100 KB" isn't as simple as it sounds: some websites count 1 KB as 1,000 bytes, others as 1,024 bytes. A file of 101,000 bytes is "98.6 KB" to one site and "101 KB" to another — and rejected by the second.

The tool aims for the stricter of the two: 100 KB means at most 100,000 bytes, so the file is accepted either way.

Quality first, then size

There are two ways to make an image smaller:

1. Compress harder — lower the JPG quality. Up to a point, this is invisible.
2. Reduce the dimensions — fewer pixels, smaller file.

The tool tries quality first and only reduces dimensions when even low quality wouldn't fit. That keeps photos looking as good as possible for their size. A typical phone photo (4,000 × 3,000 pixels, 3 MB) usually ends up around 1,200–1,600 pixels wide at 100 KB, which still looks sharp on any screen.

Where 100 KB limits come from

• Job and university applications that ask for a photo or a scanned certificate.
• Government and visa portals with strict per-file limits.
• Email signatures and newsletters, where small images load quickly.
• Forums and marketplaces with attachment limits.
• Websites, where every 100 KB saved makes pages load faster.

For smaller limits — 20 KB photos and 10 KB signatures on exam and government forms — see how to compress a photo to 20 KB or 50 KB.

If the form also has a minimum

Some forms say "between 50 KB and 100 KB". Because the result lands just under your maximum, set the maximum near the top of the range — 95 KB in this example — and you'll be inside both limits.

If the form also needs exact dimensions

When a portal asks for "200 × 230 pixels and under 50 KB", resize first with the Image Resizer (crop to the right shape first if needed), then compress the resized image to the KB limit.

iPhone photos

iPhone photos are often saved as HEIC, which many forms don't accept. Convert them with HEIC to JPG first, or pick them in Safari — iOS usually converts them to JPG automatically when uploading.

Compressing many images

To shrink a whole folder of photos without a fixed KB target, the Image Compressor compresses many images at once with a quality setting and a maximum width.

Frequently asked questions

Is my photo uploaded?

No. It's compressed in your browser, so ID photos and documents stay on your device.

Will the photo look worse?

At 100 KB, most photos look identical on screen. At very small limits (10–20 KB), some softness is unavoidable.

Can I compress PNG screenshots?

Yes — they're converted to JPG or WebP, which are far smaller for screenshots of photos and pages.