Many forms and websites only accept images under a certain size: a job application that wants a photo "under 100 KB", a marketplace with a 1 MB limit, a profile picture that must be "less than 500 KB". Your photo is usually several megabytes.
This guide shows how to get under any limit while keeping as much quality as possible. Every number below was measured with the tools on this site.
The quick way
- Open the image compressor. For the most common limit there's a ready-made page: compress an image to 100 KB.
- Add your image (or up to 20 at once).
- Under Max file size, choose the limit: 100 KB, 200 KB, 500 KB, 1 MB, 2 MB or 5 MB. For any other size, type it in the Custom box in MB, for example
0.3for 300 KB. - Click Compress. Each result shows its real file size and, if quality had to be lowered, by how much.
- Download the file, or all of them as a ZIP.
The compressor doesn't guess. It tries quality settings and keeps the highest quality whose file still fits under your limit. Images that already fit are left at your chosen quality.
What happens to the quality: a real example
We made a detailed, grainy 3000 × 2000 test photo, the kind that's hard to compress. Saved as a high-quality JPG, it was 3.1 MB.
| Limit | Result | Quality used |
|---|---|---|
| 500 KB | 486 KB | 61 |
| 100 KB | 90.7 KB | 23 |
At 500 KB the photo still looks good. Forcing the same 3000 × 2000 photo under 100 KB needs quality 23, which shows visible blocks and smeared detail.
That leads to the most important tip.
Small limit? Resize first
A file's size depends mostly on how many pixels it has. A 3000 × 2000 photo has 6 million pixels. Most forms show the picture far smaller than that.
So we used the image resizer with a width of 1200 pixels and the same 100 KB limit:
| Settings | Result | Quality used |
|---|---|---|
| 3000 × 2000, max 100 KB | 90.7 KB | 23 |
| Resized to 1200 × 800, max 100 KB | 78.1 KB | 79 |
Same limit, much better picture: at 1200 × 800 the photo fits at quality 79, which is hard to tell apart from the original at normal viewing size.
Rule of thumb: for limits of 200 KB or less, resize photos to about 1000–1600 pixels on the long side first. The resizer has the same Max file size setting, so you can do both in one step.
Screenshots and graphics (PNG)
Screenshots, logos and diagrams behave differently from photos. They have large flat areas of colour, which PNG stores very efficiently.
Our 1600 × 1000 test screenshot (a dashboard with text and coloured boxes) was 94.7 KB as a PNG. The compressor's default Balanced level brought it to 36.6 KB, still as a PNG, well under a 100 KB or 200 KB limit, with no visible change.
A photo saved as PNG is different: it can be huge, and reducing colours to fit a small limit can cause visible banding (stripes in smooth areas such as sky). With the format on Auto, the compressor saves such a photo as a high-quality JPG instead, or WebP if it has transparent areas, and tells you it did. That almost always looks better. More on choosing formats: PNG, JPG or WebP.
Common questions
Is 100 KB exactly 100,000 bytes? Here, 1 KB means 1,024 bytes, so 100 KB is 102,400 bytes, the way Windows and most websites count. If a form is very strict and counts 1 KB as 1,000 bytes, type 0.095 in the Custom box to stay safely under both.
What if it still doesn't fit? The result says so plainly. Make the image smaller in the resizer and try again.
Does compressing change the width and height? The compressor doesn't: it keeps the dimensions and only changes how the file is stored. Use the resizer to change dimensions.
Are my images uploaded anywhere? No. Everything runs in your browser on your own device, so it's safe for ID photos and private documents.
Summary
- Choose the limit under Max file size, or type your own.
- The compressor finds the highest quality that fits for each image.
- For small limits (200 KB or less), resize first to around 1000–1600 pixels. The quality stays much higher.
- Screenshots usually stay sharp as PNG. Photos under a limit look best as JPG, and Auto picks it for you.
For more ways to shrink images, see how to make an image file smaller.