PAX File Extractor
PAX File Extractor is a Windows tool for .pax backup archives. Open one, extract the files you pick and save them to your PC.
Version 26.7 | Windows 11, Windows 10, Windows 8.1, Windows 7 and Windows Server
PAX File Extractor is a Windows tool for .pax backup archives. Open one, extract the files you pick and save them to your PC.
Version 26.7 | Windows 11, Windows 10, Windows 8.1, Windows 7 and Windows Server
A .pax file can hold six different layouts. The extension names none of them.
What it does
From opening a .pax archive to saving the files you select.
A .pax file can be built six different ways. The file name itself gives no clue, although the archive does. Because the tool reads the first few bytes on open, it names the layout on screen.
Older tools cut file paths at 100 characters, so long names are lost. PAX writes a longer record alongside each file, in addition to the plain header. The tool reads that record, so the whole name and folder path are kept.
Open the archive and every entry is listed with its owner, its group and its read or write permissions. As well as the mode bits, the tool shows all of it next to each entry. Because nothing is hidden, you can tell a system file from a personal one before exporting.
A PAX archive moved between servers can hold tens of thousands of entries, so scrolling is not an option. Type any part of a name in the search box and the list drops to the few that match.
Tick the files you want, then pick a folder on your PC. Nothing else is written. Because the .pax file is only ever read, your original stays exactly as it was.
Reading a PAX file normally means a Mac, a Linux box or the Windows Subsystem for Linux, although none of that is needed here. This is a standard Windows program that runs on Windows 11 back to Windows 7 and on Windows Server.
Before you try another reader
A PAX file that refuses to open is rarely damaged. In most cases it is a reader that stopped short of the extended records.
Identify the layout first, then export the entries you need.
Choose the file from a share, a disk or a folder, although the extension may be missing. The tool only reads it, so a file that turns out to be something else is left unchanged.
Renamed or extensionless files behave identically. The name itself is never what gets tested.
Every archive says how it was built in its first few bytes. The tool reads them and names the layout on screen, whether that is ustar, an older tar or one of the cpio layouts. Because the POSIX standard requires readers to check this, the answer is not a guess.
If it is not an archive at all, you are told that rather than shown an error.
PAX stores the real file name in a second record when the first one is too small to hold it. Because the tool reads that second record, it uses what is in it. That is why a long path is kept in full instead of cut short.
A global record applies to everything after it, so you only meet it once, at the front.
An archive built to move a whole server can hold thousands of files, so a listing alone is not enough. Type any part of a name and the list shrinks to what matches.
Matching runs against the full path from the extended record, not the truncated one.
Your selection goes to a folder you pick, with the folder structure and dates the archive recorded. Windows has its own limit on name length. Where that limit applies, the tool still shows the full name on screen.
The file you opened is never written to at any point.
A file called pax_global_header beside your extracted folders means an older tool did not recognise a PAX record and saved it as a file. The archive itself is intact. It needs a reader that handles the record.
The same goes for warnings about an unknown extended header keyword.
A tree of files with enough description attached to rebuild it faithfully somewhere else.
Deep directory trees are carried at full length, along with names written in any script. That is the case the plain header could never handle. It is also the reason the interchange format exists at all.
The plain header holds numeric UID and GID plus name fields of up to 32 characters. Anything longer moves into the record beside it. All of it is shown, since Windows can act on none of it.
A symbolic link keeps its target in a linkpath record, so it still points at the right file. Hard links keep theirs too. A sparse file is one stored with its empty parts left out to save room. That saving is preserved on export, so Windows can keep it.
Yes, once you know what is inside. The extension stays neutral on purpose, so it promises nothing.
Portable archive interchange
That is what the name is short for. Its authors wanted one tool that could read both tar and cpio archives.
Pax lists before it extracts
It has four modes. Giving no flag at all puts it in list mode rather than extracting anything.
Ustar unless told otherwise
Most builds write plain ustar by default rather than the interchange format. The specification leaves that choice to the implementation, which is why -x ustar exists to force it.
A file named .pax is very often a plain TAR archive.
The pax utility reads and writes six container layouts.
The default output, also the base the interchange format builds on.
Some .pax files are not archives at all. A genealogy program and an image compression format both claim the extension, so the first useful thing any reader can do is say which of these you are actually holding.
Three of the four cost nothing. What separates them is how much of the extended header each one reads.
| Route | Every layout |
Extended headers |
Says what the file is |
Nothing to install |
|---|---|---|---|---|
| An everyday archive toolFreeOpens it from the context menu, treating it as a tar | ||||
| The pax command itselfFreeFree on macOS and BSD, but it is a typed command with no window to click in | ||||
| A browser based extractorFreeNo install needed, though only some keep your data local | ||||
| PAX file extractorDemoNames the layout, reads the records, exports your pick |
YesPartlyNo
The pax command ships with macOS and BSD. Most Linux installs need the package first. On Windows none of these are present, which is where the PAX file extractor comes in.
The record in front of the entry
The interchange format exists to carry the things the plain tar header was too small to hold.
A ustar header is a fixed block of fields, every one sized decades ago. When a path outgrew it or a file did, there was nowhere to put the real value. The pax answer was a small text record sitting in front of the entry with that value in it.
Where the plain header runs out
Plain text, so you can read these in any hex viewer. The self describing length lets a reader skip a record it does not recognise.
This is why an old PAX extractor mangles a modern archive. It reads the plain header, finds a truncated path and a wrong size, then never looks at the record holding the truth. Nothing is corrupt.
Nothing about this format calls for the higher tiers.
Recommended for PAX
$49one time
Standard edition
Professional, $99 covers the enterprise images and tape. An interchange archive calls for none of them.
Point the PAX file extractor at your file. It names the layout and lists what is inside.
Current for Backup Extractor 26.7. BitRecover has worked on recovery and conversion tools since 2011.
Almost always from moving something between two systems that did not agree on much else.
The format was built for data interchange and for file backup, so PAX archives appear wherever data moved between systems.
A folder tree moved off z/OS, where the pax command is part of the system.
Any machine where the pax command has always been present, so no extra tool was needed.
A move where neither side trusted the tar built into the other system.
Installer payloads packed as one archive, because it had to open everywhere.
Where it ends up
An archive built to be portable, sitting on a Windows machine that has no pax command and no obvious way to look inside.
Portability is the point of the format. The system at the end of the chain is the one without pax.
Common questions once the extension turns out to guarantee nothing.
No. The extension is also used by a genealogy program, by an image compression format and by a handful of unrelated applications. Open it in the PAX file extractor and the first bytes answer that before anything else.
One of six container layouts. The pax utility reads and writes ustar, old tar and four cpio layouts including the old binary one. Most builds default to ustar rather than the interchange format, though the specification lets each one choose.
Yes. Opening the archive lists every entry with its full path, size, date and owner. Nothing is written to disk, so the file you were sent stays untouched until you export.
Very often, yes. The extension was chosen to stay neutral between tar and cpio, so the name tells you nothing about the layout underneath it.
Extended header records, written as key and value pairs ahead of each file. They carry the long paths, large sizes, sub second timestamps and UTF-8 names that plain ustar has no room for.
An older extractor met a global extended header, did not recognise it and wrote it out as an ordinary file. The archive is fine. The reader was too old to understand the record.
Yes. Find the entry in the PAX file extractor, tick it and write it out. Everything else is left untouched.
Only for what is inside it. AIX and z/OS both ship pax and write the same interchange records, so a set moved off a mainframe reads the same way as one from any Unix.
They are read from the extended header and shown in full. That is the whole reason the record exists, since the plain header could never hold them.
The mode appears against each entry, along with the numbers behind the owner and group and the account names themselves. There is nothing on a Windows machine to hand them to, so they sit there as information.
It opens the file, names which layout it holds and lists every entry at its untruncated length. Writing files out is the only thing held back. On this format, identifying what you have is often enough.
Standard at $49. PAX sits in the entry tier with TAR, CPIO and DUMP, so Professional adds nothing this format needs.
PAX File Extractor
Open the file, read the layout it reports and take out whatever turns out to be inside.
Version 26.7 · Windows 11, Windows 10, Windows 8.1, Windows 7 and Windows Server