# ect > Efficient Compression Tool. > File optimizer written in C++. It supports `.png`, `.jpg`, `.gzip` and `.zip` files. > More information: . - Compress a file: `ect {{path/to/file.png}}` - Compress a file with specified compression level and multithreading (1=Fastest (Worst), 9=Slowest (Best), default is 3): `ect -{{9}} --mt-deflate {{path/to/file.zip}}` - Compress all files in a directory recursively: `ect -recurse {{path/to/directory}}` - Compress a file, keeping the original modification time: `ect -keep {{path/to/file.png}}` - Compress a file, stripping metadata: `ect -strip {{path/to/file.png}}`