CapyResize · tool no. 8
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Starts at a lower quality than the converter. The savings shown are measured, not guessed.
Make an image's file smaller in your browser by lowering the quality and, if you like, the width; the savings shown are measured after the image is actually encoded.
Updated · by Unfolding Dimensions
01 · The drop
The guide
How to compress an image
- Step 1
Drop an image. JPG is selected and the quality starts at 0.70, lower than the converter's 0.85.
- Step 2
Lower the quality or set a smaller width — the width usually saves more — and compare the preview as you go.
- Step 3
Read the “before → after” line for the real saving, then download the smaller file.
A file gets smaller in two ways: lower quality, or fewer pixels. A phone photo can be thousands of pixels wide, far more than a web page shows, so cutting the width often saves more than any quality setting. Both controls are on the dial, and the before-and-after figure compares the new file with the exact size of the one you dropped.
JPG is the starting format because every device opens it and every browser can write it. WebP is often smaller still and is one click away, but some browsers — Safari among them — can't encode it and quietly write a PNG, which is the opposite of smaller. When that happens the tool tells you, and names the file .png so the extension is true. JPG has no transparency, so transparent areas are filled with the “Flatten onto” colour; choose WebP if you need to keep them.
If the file was already well compressed, re-encoding can make it larger. The line says so, and then the original is the one to keep.
Questions
How much smaller will my image get?
It depends on the picture and the settings, so the tool doesn't promise a figure. It encodes the file for real and shows the exact before and after.
Will compressing change how it looks?
JPG and WebP at lower quality discard detail, and the preview shows what you'll get. Your original file is never touched; you download a new one.
Can I compress a PNG?
Yes, two ways: convert it to JPG or WebP and lower the quality, or keep PNG and set a smaller width. PNG itself has no quality setting, so its size only falls as the width does.
Is my image uploaded to compress it?
No. The compression happens in your browser, so nothing is sent or stored.