Open a ZIP and extract files

Supported formats

• ZIP (.zip) only. Supported compression methods are “stored” and “Deflate”, which covers most ZIP files. ZIP files over 4 GB (ZIP64) can be read too.
• 7z, RAR, tar, gzip and other formats are not supported. If you choose one, the tool tells you which format it is.
• Password-encrypted files and files using other compression methods (LZMA, BZIP2 and so on) appear in the list but cannot be extracted.
• ZIP files split into several parts are not supported.

How extraction works

• The whole file is not loaded. Only the file list and the parts of the files you extract are read.
• Save files one by one, or save the selected files together as one ZIP. That ZIP stores the extracted files without compressing them again and keeps the folder structure.
• Each extracted file is checked against its checksum (CRC-32) and size before it is saved. If they do not match, it is not saved.
• A ZIP inside the ZIP (a nested archive) is not unpacked; it is extracted as it is.

File name encoding

ZIP files made by some older Windows software do not mark the encoding of their file names, so names can look garbled. If every name can be read as UTF-8, the tool uses UTF-8. Otherwise it tries a fixed order — Shift_JIS, GB18030, Big5, EUC-KR, EUC-JP — and uses the first one that reads every name without errors. If none does, it uses the ZIP default, CP437. The guess does not depend on the page language. If names look wrong, choose another encoding.

Safety rules

• Names containing “..”, absolute paths, drive letters, backslashes, control characters or reserved Windows names (CON, NUL and so on) are corrected before extraction. The list shows both the corrected and the original name.
• Names that differ only in upper or lower case get a number from the second one on.
• Links (symbolic links) are not extracted.
• Files that expand to an extreme size (over 1 MB with a compression ratio above 1,000) are not extracted. During extraction, the tool also stops as soon as more data comes out than declared.
• Extracted files are never opened or run automatically. Previews show only images and text, and SVG is shown in a way that does not run scripts.

Limits

• ZIP files up to 8 GB, with up to 50,000 files inside.
• Up to 1 GB per extracted file, and up to 1 GB in total for the files saved together as a ZIP.
• Previews show the first 4 KB of text, and images up to 20 MB.

The file is read on this device and is not saved or sent.