Make a zip file
Bundle files or a whole folder into one zip, with folder structure kept and already-compressed files left alone.
Photos, video, audio and other archives are stored without recompressing, whatever you pick. They’re already compressed and wouldn’t get smaller.
A folder keeps its structure inside the zip.
The zip is built on this device. Nothing is uploaded.
What compresses and what doesn’t
Compression finds repetition and a file that has already been compressed has had its repetition removed. So a zip of text, spreadsheets exported as CSV, source code or uncompressed images can shrink to a fraction of the original, while a zip of photos or video ends up almost exactly the same size. The result row shows how many files were compressed and how many were stored as they were.
When to zip at all
For bundling, mostly. Sending forty files as one attachment, keeping a folder's structure intact or getting past a system that only accepts a single upload. As a way to make photos smaller it does almost nothing; the compressor and the resizer are the tools for that.
Compression levels
Normal is the right choice nearly always. Maximum spends noticeably more time for a few percent on text-heavy files and nothing at all on media. None stores everything, which is fastest and makes sense when the archive is only a container for files that are already compressed.
Common questions
Why did my zip barely get smaller?
Because most of what people zip is already compressed. Photos, video, audio, PDFs with images and Office documents, which are zip files themselves, have little left to squeeze. Text, CSV, code and uncompressed images shrink a lot; a folder of phone photos barely changes.
Why are some files stored rather than compressed?
Compressing an already compressed file costs time and usually saves nothing, occasionally making it a few bytes larger. Files with extensions known to be compressed, such as JPG, MP4, MP3 and DOCX, are stored as they’re and everything else is compressed at the level you choose.
Can I zip a whole folder?
Yes. Choose a folder and every file in it is added with its path, so the archive unpacks to the same structure. Choosing individual files puts them all at the top level of the zip.
Is there a size limit?
No imposed limit, because nothing is uploaded. Everything is held in the tab while the zip is built, so the practical ceiling is your device’s memory, which on most computers is several gigabytes of files.
Will the zip open everywhere?
Yes. It is a standard zip that Windows, macOS and Linux open without any extra software and file names are stored as UTF-8 so accented and non-Latin names come through correctly.
Guides
The other tools
All of them work the same way: the file is read in your browser and never uploaded.