Compress an image to any size in KB
Type the size your form or website asks for. Graviton finds the sharpest version that fits, on your device.
Drop your images here
JPG, PNG, WebP, AVIF, HEIC and GIF, up to 100 MB each
How it works
Compress in three steps
- 1
Drop your image in. JPG, PNG, WebP, AVIF and iPhone HEIC all work.
- 2
Graviton searches for the highest quality that fits under 100 KB, keeping the original width and height.
- 3
Download a JPG that is ready to upload.
Common size limits
Exam and ID portals often ask for 20–50 KB photos and 10–20 KB signatures. Visa and job forms usually allow 100–240 KB. Email and chat uploads are often capped at 1–25 MB. Always check the exact limit on your form.
How the exact-size search works
Graviton encodes your image several times and keeps the best one under your target, at the original width and height. If that needs very heavy compression, turn on "Shrink dimensions if needed" and Graviton reduces the dimensions a little at a time, which looks better than heavy compression artifacts.
Frequently asked questions
Is 1 KB 1,000 or 1,024 bytes?
Graviton counts 1 KB as 1,000 bytes, the stricter of the two. A file under 50 KB here is also under 50 KB on forms that count 1,024 bytes per kilobyte.
What formats can I get?
JPG by default, because almost every form accepts it. You can switch to WebP, AVIF or PNG in the settings.
Are my images uploaded?
No. Graviton converts and compresses inside your browser, so your images never leave your device. Nothing is sent while you compress. When you download, the browser sends only a one-way fingerprint of the image, so the download can be counted and approved. Graviton stores none of it.
Is it free?
Yes. Compressing and converting are free and unlimited, with no account needed. Downloading needs a free account, which includes 3 downloads a day with every format and setting. Pro removes the daily limit.