Google's image compression web tool -- Squoosh

Squoosh is an image compression web app from Google Chrom Labs. As the team said, it uses WebAssembly to do more with the codes the browser doesn’t have baked in. Although it needs to be loaded in a browser, it uses local resources. After launched once, you can even use it off line.

Try it by opening Squoosh in a browser, it launches very fast. Then you can drag and drop an image into the browser. It provides many advanced options, such as size, quality, image compressor – WebP, PNG, JPEG (Yes, you can use it to convert the image format). There will be a preview to see the previous and the resulting image quality affected by the options selected instantly, and you will be told how much smaller the resulting image will be.

Alternatives

• TinyPNG , online tool, work with JPEN and PNG, handle up to 20 images at once, no so many options, no preview.
• RIOT , Windows tool, work with JPEG PNG GIF, handle bunches images at once, resize, preview.