How to use
- Drop the photos you want to compress, or click to choose them. You can add several at once.
- Adjust the quality slider. The default of 75 is usually indistinguishable from the original while cutting the file size substantially.
- Check the size before and after and the savings for each file, then download them individually or as a ZIP. Use the “Original” toggle in the preview to compare quality.
Compression runs entirely in your browser; your photos are never uploaded.
Quality settings at a glance
| Quality | What you get | Good for |
|---|---|---|
| 90+ | Near-original, modest savings | Archiving, printing |
| 70–89 | Hard to tell apart on a normal screen | Blogs, online stores, messaging (recommended) |
| 40–69 | Soft edges and smudges when zoomed in | Uploads with tight size limits |
| Below 40 | Visible blocky artifacts | Small previews |
Savings are calculated as (1 − after ÷ before) × 100: a 4.0 MB photo that becomes 1.0 MB is 75% smaller. If you need to land under a specific limit such as 200 KB, Compress Image to Size finds the quality for you.
How each format gets smaller
- JPG, WebP and AVIF are lossy. Lower quality discards detail your eyes are less likely to notice.
- PNG is lossless and has no quality setting, so re-saving it as PNG barely changes the size. This tool shrinks PNGs by converting them to WebP (transparency kept) or JPG. If you must keep the PNG format — for a logo or screenshot — you need a PNG optimizer that quantizes the image to 256 colors or fewer.
- Auto keeps JPGs as JPG and WebPs as WebP, and converts PNG, GIF and BMP to WebP. Where the browser cannot save WebP, JPG is used instead.
Things to know
- Already-compressed images may not shrink, or may even grow. That is why “Keep the original if the result is larger” is on by default.
- Reducing dimensions has the biggest effect. If a 4000px photo is going on a blog, resize it to around 1920px with Resize Image before compressing.
- EXIF data, including GPS location, is removed. Good for privacy — but keep the original if you need the capture date.
FAQ
Does compressing again keep making files smaller?
Each re-save of a lossy format loses a little quality, but repeating the same quality setting barely reduces size. Compress once, from the original, at the quality you want.
Can I compress iPhone HEIC photos?
Most browsers other than Safari cannot open HEIC. Set iPhone Settings → Camera → Formats to “Most Compatible” to shoot JPG instead.