git-pack-objects [-q] [--no-reuse-delta] [--delta-base-offset] [--non-empty] [--local] [--incremental] [--window=N] [--depth=N] [--all-progress] [--revs [--unpacked | --all]*] [--stdout | base-name] < object-list


Reads list of objects from the standard input, and writes a packed archive with specified base-name, or to the standard output.

A packed archive is an efficient way to transfer set of objects between two repositories, and also is an archival format which is efficient to access. The packed archive format (.pack) is designed to be unpackable without having anything else, but for random access, accompanied with the pack index file (.idx).

git-unpack-objects command can read the packed archive and expand the objects contained in the pack into "one-file one-object" format; this is typically done by the smart-pull commands when a pack is created on-the-fly for efficient network transport by their peers.

Placing both in the pack/ subdirectory of $GIT_OBJECT_DIRECTORY (or any of the directories on $GIT_ALTERNATE_OBJECT_DIRECTORIES) enables git to read from such an archive.

In a packed archive, an object is either stored as a compressed whole, or as a difference from some other object. The latter is often called a delta.



Write into a pair of files (.pack and .idx), using <base-name> to determine the name of the created file. When this option is used, the two files are written in <base-name>-<SHA1>.{pack,idx} files. <SHA1> is a hash of the sorted object names to make the resulting filename based on the pack content, and written to the standard output of the command.


Write the pack contents (what would have been written to .pack file) out to the standard output.


Read the revision arguments from the standard input, instead of individual object names. The revision arguments are processed the same way as gitlink:git-rev-list[1] with --objects flag uses its commit arguments to build the list of objects it outputs. The objects on the resulting list are packed.


This implies --revs. When processing the list of revision arguments read from the standard input, limit the objects packed to those that are not already packed.


This implies --revs. In addition to the list of revision arguments read from the standard input, pretend as if all refs under $GIT_DIR/refs are specified to be included.

--window=[N], --depth=[N]

These two options affect how the objects contained in the pack are stored using delta compression. The objects are first internally sorted by type, size and optionally names and compared against the other objects within --window to see if using delta compression saves space. --depth limits the maximum delta depth; making it too deep affects the performance on the unpacker side, because delta data needs to be applied that many times to get to the necessary object. The default value for both --window and --depth is 10.


This flag causes an object already in a pack ignored even if it appears in the standard input.


This flag is similar to --incremental; instead of ignoring all packed objects, it only ignores objects that are packed and not in the local object store (i.e. borrowed from an alternate).


Only create a packed archive if it would contain at least one object.


Progress status is reported on the standard error stream by default when it is attached to a terminal, unless -q is specified. This flag forces progress status even if the standard error stream is not directed to a terminal.


When --stdout is specified then progress report is displayed during the object count and deltification phases but inhibited during the write-out phase. The reason is that in some cases the output stream is directly linked to another command which may wish to display progress status of its own as it processes incoming pack data. This flag is like --progress except that it forces progress report for the write-out phase as well even if --stdout is used.


This flag makes the command not to report its progress on the standard error stream.


When creating a packed archive in a repository that has existing packs, the command reuses existing deltas. This sometimes results in a slightly suboptimal pack. This flag tells the command not to reuse existing deltas but compute them from scratch.


A packed archive can express base object of a delta as either 20-byte object name or as an offset in the stream, but older version of git does not understand the latter. By default, git-pack-objects only uses the former format for better compatibility. This option allows the command to use the latter format for compactness. Depending on the average delta chain length, this option typically shrinks the resulting packfile by 3-5 per-cent.


Written by Linus Torvalds <>


Documentation by Junio C Hamano

See Also

gitlink:git-rev-list[1] gitlink:git-repack[1] gitlink:git-prune-packed[1]


Part of the gitlink:git[7] suite