What Is Inside This Archive

Features

• Drop in ZIP / JAR / APK / DOCX / XLSX / PPTX / EPUB / WAR / IPA / CRX and more
• Reads only the central directory, so huge archives list instantly
• A tree list: indentation shows the directory depth, and directory rows stand apart from file rows
• Each file row shows its uncompressed / compressed size, its own compression ratio and the method
• The summary reports file count, directory count, total uncompressed, total compressed and overall ratio (counting only entries that record a compressed size; the wording in the result says so)
• ⚠️ A stored (uncompressed) entry has a ratio of 0%; a streamed entry with no recorded compressed size says "not recorded" instead of a wrong number
• Flags encrypted members and directory entries
• Filter by file name (say, only .js), and sort by name or size
• Handles zip64 (archives over 4 GB or over 65535 entries)
• Forgiving parsing: where the directory cannot be read, it lists what it can rather than failing outright
• The file is never uploaded; everything happens locally

How to use

1. Drop the archive into the area above (or click to choose a file)
2. Read the file count and totals; use the filter to narrow to one kind of file
3. Copy a file name with the button on its row

FAQ

Why is it so fast? Is it guessing?

It is exact, and the speed comes precisely from not decompressing. The three key facts — file names, both sizes, and the compression method — are all registered in the central directory at the end of the file. That is a directory required by the format, not an estimate, so “how many files and how big unpacked” is read rather than computed. Retrieving the actual contents would mean following each entry’s offset and decompressing, which this tool does not do.

Why does `.tar.gz` not work?

Because it is two layers: gzip wrapping a single tar stream. gzip compresses one stream and has no notion of “files”, so there is no listing inside it; tar has the listing, but it is buried under the gzip. Feed it to the gzip tool first to get a `.tar`, then look inside that — though a tar’s structure is entirely different from ZIP, and this site has no tar tool.

Can it list the names in an encrypted archive?

Yes, and that is not a shortcut this tool takes — ZIP encryption protects file contents, not the central directory. The directory plainly records each member’s name, size and method, and every ZIP tool can read it. It also means that when you send a password-protected ZIP, the file names and sizes remain visible; hiding those takes a different format.