Zip files and folders, or open a ZIP and take out single files.
Add files to put in the ZIP.
It does the two everyday jobs with ZIP files. On the Create ZIP tab it packs the files, or a whole folder, that you choose into one archive that you download. On the Open ZIP tab it reads an archive, lists what is inside with sizes and dates, and lets you download single files or a handful at once. Everything happens in your browser: the files are read from your disk by the page and are never uploaded, which matters for contracts, backups and photos.
As a sense of scale: a 1,000-row CSV export of 22,579 bytes comes out at roughly 5,000 bytes with compression, while 5,000 bytes of random data, like an encrypted file or a photo, stay at 5,000 bytes. The exact compressed size can differ a little between browsers because each ships its own compressor.
Choose or drop a .zip file. Only the list of files is read first, not the whole archive, so even a large ZIP opens at once. Each row shows the stored name, the size once unpacked, and the date. Press Download on a row to unpack just that file, or tick up to 20 files and download them together; a browser may ask you to allow several downloads, and you should say yes.
Before a file is saved, its CRC-32 checksum is compared with the one in the archive. For reference, the CRC-32 of the nine characters 123456789 is CBF43926. If the checksum does not match, the file is damaged and the tool says so instead of handing you a broken file. To compare a whole download against a published hash, use the file hash checker and read how to verify a download.
A ZIP contains names written by whoever made it. A hostile archive can hold a name such as ../../etc/passwd, hoping that an extractor writes outside its folder. This is called zip slip. Here a stored name is only ever shown as text, and the name your browser saves under is the last part of the path, with folders, dot-dot segments, drive letters, control characters and reserved Windows names removed. So ../../etc/passwd is saved as passwd.
A small file can also be built to inflate into gigabytes, a "zip bomb". The tool refuses a file that unpacks to more than 500 MB, stops the moment the unpacked data passes the size the archive declared, and stops data that expands more than any valid compressed stream can.
Password-protected entries, archives bigger than 4 GB (ZIP64), archives split into several parts, and entries compressed with methods other than stored and deflate (such as BZip2, LZMA or Zstandard) are listed and clearly marked as not supported, and the rest of the archive still works. The tool does not read 7z, RAR or tar files. If your browser is too old to unpack compressed entries, stored ones still work.
Creating: up to 500 files and 1 GB in total. Opening: archives up to 2 GB, with up to 10,000 entries, and files up to 500 MB each once unpacked. To merge or split PDF files rather than archive them, see the PDF toolkit, and to shrink photos before zipping them, use the image toolkit.
No. The page reads the files from your device, builds or reads the ZIP there, and nothing is sent over the network.
JPEG, PNG, MP4 and similar formats are already compressed, so ZIP cannot squeeze them much. The tool detects this and stores such a file as it is. A ZIP is still useful for sending many files as one.
No. Encrypted entries are shown with a lock and marked as not supported. The tool never asks for or stores a password.
When you download several files at once, browsers ask once for permission, to stop sites from flooding you. Allow it and the rest arrive one after another.
The data that came out does not match the checksum stored in the archive, so the file is damaged or the archive was changed. Download the ZIP again before trusting it.
