Features

Limitations

reSmush.it limits its use to PNG, JPG, GIF, BMP and TIF pictures for FREE up to 5MB.

Library used

reSmush.it provides a FREE optimization of pictures, for the most standard filetypes (PNG, JPG, GIF, BMP and TIF). It allows reductions until 80% by using differents algorithms :

• PNGQuant to strip unneeded chunks from PNGs. PNGQuant is a lossy compression library for PNG images. This library preserves a full alpha transparency. See www.pngquant.org for more informations.
• JPEGOptim provides lossless optimization (based on optimizing the Huffman tables). JPEGOptim is one of the most efficient library for JPG conversion among JpegTrans, mozjpeg and jpegrescan. See github.com/tjko/jpegoptim for more informations.
• OptiPNG is based on PNGCrush, and also includes part of PNGRewrite code for palette rewriting. Unlike PNGCrush, all trials are performed in memory, and it does some image reductions automatically. It's a PNG reducer that's used by lot of online optimizers. See optipng.sourceforge.net for more informations.

EXIF data

EXIF data are by default removed from pictures. It can be preserved if needed (read API).

Optimization examples

Jpeg comparison

Original picture (left) 178,6 Kb, Optimized picture (right) 78,4 Kb gain 56%

PNG comparison

Original picture (left) 186,1 Kb, Optimized picture (right) 69,6 Kb : gain 63%