Image compressor

What it does

When you need to compress image online without handing files to a server, this compressor does the work inside your browser. Pick one or more JPG, PNG or WebP files, set the quality, and each one is decoded and re-encoded on your device. You see the size before and after, the percentage saved and the pixel dimensions of every file. You can also cap the width so oversized phone photos shrink to something a web page can use. Download the files one at a time or all together as a zip.

How to use it

1. Choose your images. A sample photo is loaded so you can try the settings first.
2. Set the quality. Start at 75% for photos and adjust while watching the "Saved" figure.
3. Pick the output format. Keep the original, or switch to WebP for the smallest files.
4. Tick "Also limit the width" if the originals are larger than they will ever be displayed, and enter a maximum such as 1,600 px.
5. Download each file, or all of them as a zip.

How to read the result

The three figures at the top cover every file you added. Before is the total original size, After is the total once compressed, and Saved is the difference as a percentage. Each row in the table shows the same for one file, with its final dimensions.

Say a photo straight from a phone is 4,000 × 3,000 pixels and 3.2 MB. At 75% quality with the width capped at 1,600 px, it might come out around 250 KB, a saving of about 92%. Most of that comes from the resize: the original has more than six times the pixels the page can show at that width.

If Saved shows 0% with the hint "larger: lower the quality", the new files are bigger than the originals. That happens with images that were already compressed hard, and with PNG output. Lower the quality, switch to WebP, or keep the original.

Transparent PNGs saved as JPG get a white background, because JPG has no transparency.

To change format without touching the quality settings, use the WebP converter. Image weight is usually the first thing we fix in a technical SEO audit.