Guide
How to compress an image to 100KB, 200KB or a specific size
Start with a target file-size limit and let the tool reduce encoding quality. If that is not enough, reducing pixel dimensions is usually better than forcing extremely low quality.
Compress Image
Check whether the requirement is file size or dimensions
A limit such as 100KB, 200KB or 1MB refers to storage size. A requirement such as 800×600 or 1920×1080 refers to pixel dimensions. They influence each other, but they are not interchangeable. Application forms may also impose an aspect ratio and file format.
If the form only says that the file must be under 200KB, use target-size mode first. If it also requires fixed dimensions, crop to the correct ratio, resize the image, and compress it last. That order avoids repeated quality loss.
- File-size limit: for example, no more than 200KB.
- Dimension limit: for example, 600px wide by 800px high.
- Aspect ratio: for example, 1:1, 3:4 or 16:9.
- Format: for example, JPG only rather than HEIC or PNG.
Compress to a target size
- Open the JustFileKit image compressor and add a JPG, PNG or WebP file.
- Choose target file size as the compression mode.
- Enter the limit and choose KB or MB, such as 200 KB.
- Process the image, then check its actual file size, clarity and dimensions.
- Keep the original until the receiving website accepts the result.
The target is treated as a maximum. Image content, transparency and encoding behavior affect the result, so an output cannot always be exactly the requested number of bytes.
Why dimensions sometimes need to change
JPEG and WebP can save substantial space by lowering encoding quality, but excessive compression creates block artifacts, blurred text and lost detail. When the requested file size is far below the original, shrinking the dimensions often produces a more readable result than continuing to reduce quality.
JustFileKit's percentage mode preserves the original dimensions. Target-size mode first adjusts encoding quality and only scales down the image if quality changes are not enough. This helps ordinary photos stay readable while meeting strict upload limits.
Choose JPG, PNG or WebP
| Format | Best for | Compression | Watch for |
|---|---|---|---|
| JPG | Photos and ID photos | Lossy and usually easy to make small | No transparent background |
| PNG | Screenshots, text and transparency | Lossless; photos are often larger | Very small targets may require color reduction |
| WebP | Web images, photos and transparency | Efficient lossy or lossless modes | Some older upload systems accept only JPG or PNG |
A practical order of operations
For a normal photo, begin with the target-size setting. For an ID photo, fix the crop and dimensions first. For a screenshot with small text, keep PNG unless the destination rejects it. Always open the downloaded result instead of judging it by file size alone.
If a 200KB result looks too soft, remove unnecessary background with a crop and try again. Fewer pixels containing irrelevant detail often improves compression more safely than a drastic quality reduction.
Use the free tool
Choose a percentage or a target size in KB or MB