How do I zip and unzip files online without uploading them?
Updated 2026-06-27
You can zip and unzip files entirely in your browser with ZIP Create & Extract, with nothing ever uploaded to a server. The tool uses the fflate library to build and read .zip archives directly on your device, so the files you bundle or open never leave your computer. That makes it a fast, private alternative to desktop apps like WinZip or 7-Zip and to upload-based web converters, with no install and no account.
Bundle several files into one .zip
Use Create mode when you want to send or store many files as a single download. Drop your files onto the zone (or click to browse) and they stack up in a staged list.
- Add as many files as you like; the tool skips exact duplicates automatically.
- If two files share a name, they are renamed in the classic foo (2).txt style so nothing gets overwritten.
- A live Files and Total size readout tells you how big the bundle is before you commit.
When the list looks right, click Download .zip to save a single archive.zip. One thing to know: Create uses store mode, meaning files are packed together without re-compression. Photos, PDFs, and existing zips are already compressed, so the archive groups them into one tidy file rather than shrinking them much. If your goal is smaller images specifically, shrink them first with the Image Compressor, then zip the results.
Open and extract a .zip
Switch to Extract mode and drop a .zip onto the zone. ZIP Create & Extract reads it instantly and lists every entry sorted by name, along with each file's size and the total uncompressed size of the archive.
- Click the download icon on any row to save just that single file.
- Click the eye icon next to a text file to preview it inline, without downloading anything.
- Click Close to clear the archive when you are done.
The inline preview works for text-like formats including txt, md, json, csv, xml, html, svg, and common source-code files. Very long files are truncated in the preview so the page stays responsive, but the full file still downloads intact.
What it does and does not handle
A few limits are worth knowing up front:
- Encrypted zips are not supported. If you open a password-protected archive, the tool clearly tells you so instead of failing silently.
- Everything runs in memory. The entire archive is held in your tab while it works, so jobs above roughly 200 MB may be slow; the tool shows a warning at that point.
- No folder tree on create. Files are bundled as a flat list rather than rebuilt into nested folders.
Why do it in the browser?
The biggest reason is privacy. Because ZIP Create & Extract never uploads your files, there is no server copy to leak, no retention policy to read, and no wait for an upload and download round trip. Sensitive contracts, exports, and personal documents stay on your machine. It also works offline once the page has loaded, since all the zipping and unzipping logic runs locally.
Quick recap
- Create: drop files, review the staged list, click Download .zip for one archive.zip.
- Extract: drop a .zip, preview text entries, download individual files.
- Private by design: local-only via fflate, with no uploads and no account.
Whether you are packaging a set of deliverables or just peeking inside an archive someone sent you, it handles the common cases in a couple of clicks while keeping your data on your own device.