Universal File Compressor

It accepts any file, but the two things are not the same. PDFs, images, SVG, video, audio, Word, PowerPoint, Excel and text files each go to a compressor built for that format. Anything else is packaged into a ZIP, which stores the file safely but will usually not make it smaller. The tool tells you which of the two is about to happen, for every file, before you press Compress.

Because it was already compressed. JPEG, PNG, MP4, MP3, ZIP and most PDFs already use strong compression, and squeezing them again either does nothing or makes them bigger. When that happens we keep your original file and say so, rather than handing you a larger file and calling it a saving.

It reads the first few thousand bytes and matches them against the format's own signature, so a ZIP renamed to .pdf is recognised as a ZIP. The name is used only for formats that have no signature at all, such as SVG and plain text, and you are told when the contents and the extension disagree.

No. Every compressor runs inside this page using the browser's own codecs and WebAssembly. There is no request that carries your file, its name or its contents, and nothing is written to a server. Closing the tab discards everything.