Question 1

What does this tool do?

Accepted Answer

It extracts files from Debian (.deb) packages in your browser using a pure-JavaScript AR archive parser. A .deb file is an 'ar' archive containing three members: debian-binary (version string), control.tar.gz (package metadata + maintainer scripts), and data.tar.gz (the actual filesystem payload). We parse the AR header, list all three members, and let you download them individually or together as a ZIP. For control.tar.gz, we also attempt to decompress it and parse the 'control' file for the Package, Version, Architecture, Maintainer, Description and Depends fields.

Question 2

What is the AR archive format?

Accepted Answer

AR (archive) is a simple Unix format predating TAR. An AR archive starts with an 8-byte magic '!<arch>
' followed by 60-byte file headers. Each header has fields: name (16 bytes, terminated by '/' or whitespace), modification timestamp (12 bytes decimal), owner ID (6 bytes decimal), group ID (6 bytes decimal), file mode (8 bytes octal), file size (10 bytes decimal), and a 2-byte end marker '`
'. File data follows immediately and is padded to an even 2-byte boundary. AR is simpler than TAR — no checksum, no prefix field, no type flags.

Question 3

Can I see the package info?

Accepted Answer

Yes. We attempt to inflate the control.tar.gz member (using the browser's native DecompressionStream('gzip') API), parse it as a TAR archive, and locate the './control' file inside. The control file is RFC 822-style — we extract the Package, Version, Architecture, Maintainer, Installed-Size, Description, Depends, Recommends, Suggests, Conflicts, Breaks, Provides, Replaces, Section, Priority, Homepage and Source fields.

Question 4

Can I extract the data.tar.gz payload?

Accepted Answer

Yes, but as a compressed blob — we don't recursively inflate it here because the uncompressed payload of a real .deb can be tens or hundreds of MB. Use the GZIP Decompressor tool to inflate data.tar.gz into a plain .tar, then the TAR Extractor tool to list/extract individual files from it. This separation keeps each tool focused and lets us stay within the per-tool 50KB bundle budget.

Question 5

What extra features does this tool have compared to others?

Accepted Answer

10 extras: (1) Drag-drop input. (2) File tree view of AR members. (3) Search members by name. (4) Stats — total size, member count, largest member. (5) Preview text members inline (debian-binary, control, scripts). (6) Download individual members. (7) Download all members as ZIP. (8) Package info panel parsed from control (Package, Version, Architecture, Maintainer, Description, Depends). (9) History of recently extracted .deb files (localStorage — last 10). (10) Shareable URL with view options.

Question 6

Is my .deb file uploaded anywhere?

Accepted Answer

No. All AR parsing and (where applicable) GZIP inflation runs in your browser using pure JavaScript and native APIs. File contents never leave your device. Only file summaries (filename + size + member count) are saved to local history.

Question 7

What about .deb files using xz compression?

Accepted Answer

Modern .deb packages (Debian 11+ default) may use control.tar.xz and data.tar.xz. DecompressionStream('deflate-raw') can sometimes handle raw DEFLATE, but XZ is a different container format (LZMA2 inside an XZ wrapper). For .deb files with XZ members, we still list the members and let you download them; the package-info panel will skip parsing because we can't inflate XZ in pure JS without a WASM blob. Use the dpkg-deb tool on Linux or 7-Zip on Windows for full XZ support.

DEB Extractor

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