Scroll to navigation

BORG-DIFF(1) borg backup tool BORG-DIFF(1)

NAME

borg-diff - Diff contents of two archives

SYNOPSIS

borg [common options] diff [options] REPO::ARCHIVE1 ARCHIVE2 [PATH...]

DESCRIPTION

This command finds differences (file contents, user/group/mode) between archives.

A repository location and an archive name must be specified for REPO::ARCHIVE1. ARCHIVE2 is just another archive name in the same repository (no repository location allowed).

What is compared

For each matching item in both archives, Borg reports:

  • Content changes: total added/removed bytes within files. If chunker parameters are comparable, Borg compares chunk IDs quickly; otherwise, it compares the content.
  • Metadata changes: user, group, mode, and other metadata shown inline like "[old_mode -> new_mode]" for mode changes. Use --content-only to suppress metadata changes.
  • Added/removed items: printed as "added SIZE path" or "removed SIZE path".

Output formats

The default (text) output shows one line per changed path, e.g.:

+135 B    -252 B [ -rw-r--r-- -> -rwxr-xr-x ] path/to/file


JSON Lines output (--json-lines) prints one JSON object per changed path, e.g.:

{"path": "PATH", "changes": [


    {"type": "modified", "added": BYTES, "removed": BYTES},


    {"type": "mode", "old_mode": "-rw-r--r--", "new_mode": "-rwxr-xr-x"},


    {"type": "added", "size": SIZE},


    {"type": "removed", "size": SIZE}
]}


Only actual changes are included in the "changes" list. For example, a modified entry with added=0 and removed=0 is omitted.

Sorting

Use --sort-by FIELDS where FIELDS is a comma-separated list of fields. Sorts are applied stably from last to first in the given list. Prepend ">" for descending, "<" (or no prefix) for ascending, for example --sort-by=">size_added,path". Supported fields include:

  • path: the item path
  • size_added: total bytes added for the item content
  • size_removed: total bytes removed for the item content
  • size_diff: size_added - size_removed (net content change)
  • size: size of the item as stored in ARCHIVE2 (0 for removed items)
  • user, group, uid, gid, ctime, mtime: taken from the item state in ARCHIVE2 when present
  • ctime_diff, mtime_diff: timestamp difference (archive2 - archive1)

The --sort option is deprecated and only sorts by path.

Performance considerations

For archives created with Borg 1.1 or newer, diff automatically detects whether the archives were created with the same chunker parameters. If so, only chunk IDs are compared, which is very fast.

For archives prior to Borg 1.1, chunk contents are compared by default. If you did not create the archives with different chunker parameters, pass --same-chunker-params. Note that the chunker parameters changed from Borg 0.xx to 1.0.

For more help on include/exclude patterns, see the borg_patterns command output.

OPTIONS

See borg-common(1) for common options of Borg commands.

arguments

repository location and ARCHIVE1 name
ARCHIVE2 name (no repository location allowed)
paths of items inside the archives to compare; patterns are supported

options

deprecated, use --numeric-ids instead
only consider numeric user and group identifiers
Override check of chunker parameters.
Sort the output by path (deprecated, use --sort-by=path).

Option list ends without a blank line; unexpected unindent.

--sort-by FIELD[,FIELD...] Advanced sorting: specify field(s) to sort by. Accepts a comma-separated list. Prefix with > for descending or < for ascending (default). --content-only Only compare differences in content (exclude metadata differences) --json-lines Format output as JSON Lines.

Include/Exclude options

exclude paths matching PATTERN
read exclude patterns from EXCLUDEFILE, one per line
include/exclude paths matching PATTERN
read include/exclude patterns from PATTERNFILE, one per line

EXAMPLES

$ borg init -e=none testrepo
$ mkdir testdir
$ cd testdir
$ echo asdf > file1
$ dd if=/dev/urandom bs=1M count=4 > file2
$ touch file3
$ borg create ../testrepo::archive1 .
$ chmod a+x file1
$ echo "something" >> file2
$ borg create ../testrepo::archive2 .
$ echo "testing 123" >> file1
$ rm file3
$ touch file4
$ borg create ../testrepo::archive3 .
$ cd ..
$ borg diff testrepo::archive1 archive2
[-rw-r--r-- -> -rwxr-xr-x] file1


   +135 B    -252 B file2
$ borg diff testrepo::archive2 archive3


    +17 B      -5 B file1
added           0 B file4
removed         0 B file3
$ borg diff testrepo::archive1 archive3


    +17 B      -5 B [-rw-r--r-- -> -rwxr-xr-x] file1


   +135 B    -252 B file2
added           0 B file4
removed         0 B file3
$ borg diff --json-lines testrepo::archive1 archive3
{"path": "file1", "changes": [{"type": "modified", "added": 17, "removed": 5}, {"type": "mode", "old_mode": "-rw-r--r--", "new_mode": "-rwxr-xr-x"}]}
{"path": "file2", "changes": [{"type": "modified", "added": 135, "removed": 252}]}
{"path": "file4", "changes": [{"type": "added", "size": 0}]}
{"path": "file3", "changes": [{"type": "removed", "size": 0}]}
# Use --sort-by with a comma-separated list; sorts apply stably from last to first.
# Here: primary by net size change descending, tie-breaker by path ascending
$ borg diff --sort-by=">size_diff,path" testrepo::archive1 archive3


    +17 B      -5 B [-rw-r--r-- -> -rwxr-xr-x] file1
removed         0 B file3
added           0 B file4


   +135 B    -252 B file2


SEE ALSO

borg-common(1)

AUTHOR

The Borg Collective

2025-10-31