If the commit is a merge, and if the pretty-format is not oneline, email or raw, an additional line is inserted before the Author: line. This line begins with "Merge: " and the hashes of ancestral commits are printed, separated by spaces. Note that the listed commits may not necessarily be the list of the direct parent commits if you have limited your view of history: for example, if you are only interested in changes related to a certain directory or file.

There are several built-in formats, and you can define additional formats by setting a pretty.<name> config option to either another format name, or a format: string, as described below (see git-config[1]). Here are the details of the built-in formats:

oneline

This is designed to be as compact as possible.
short
```
commit <hash>
Author: <author>
```

medium

commit <hash>
Author: <author>
Date:   <author-date>

full

commit <hash>
Author: <author>
Commit: <committer>

fuller

commit <hash>
Author:     <author>
AuthorDate: <author-date>
Commit:     <committer>
CommitDate: <committer-date>

reference
```
<abbrev-hash> (<title-line>, <short-author-date>)
```
This format is used to refer to another commit in a commit message and is the same as --pretty='format:%C(auto)%h (%s, %ad)'. By default, the date is formatted with --date=short unless another --date option is explicitly specified. As with any format: with format placeholders, its output is not affected by other options like --decorate and --walk-reflogs.

email

From <hash> <date>
From: <author>
Date: <author-date>
Subject: [PATCH] <title-line>

mboxrd

Like email, but lines in the commit message starting with "From " (preceded by zero or more ">") are quoted with ">" so they aren’t confused as starting a new commit.
raw

The raw format shows the entire commit exactly as stored in the commit object. Notably, the hashes are displayed in full, regardless of whether --abbrev or --no-abbrev are used, and parents information show the true parent commits, without taking grafts or history simplification into account. Note that this format affects the way commits are displayed, but not the way the diff is shown e.g. with git log --raw. To get full object names in a raw diff format, use --no-abbrev.
format:<format-string>

The format:<format-string> format allows you to specify which information you want to show. It works a little bit like printf format, with the notable exception that you get a newline with %n instead of \n.

E.g, format:"The author of %h was %an, %ar%nThe title was >>%s<<%n" would show something like this:
```
The author of fe6e0ee was Junio C Hamano, 23 hours ago
The title was >>t4119: test autocomputing -p<n> for traditional diff input.<<
```
- Placeholders that expand to a single literal character:
  
  %n
  
  newline
  
  %%
  
  a raw %
  
  %x00
  
  print a byte from a hex code
- Placeholders that affect formatting of later placeholders:
  
  %Cred
  
  switch color to red
  
  %Cgreen
  
  switch color to green
  
  %Cblue
  
  switch color to blue
  
  %Creset
  
  reset color
  
  %C(…)
  
  color specification, as described under Values in the "CONFIGURATION FILE" section of git-config[1]. By default, colors are shown only when enabled for log output (by color.diff, color.ui, or --color, and respecting the auto settings of the former if we are going to a terminal). %C(auto,...) is accepted as a historical synonym for the default (e.g., %C(auto,red)). Specifying %C(always,...) will show the colors even when color is not otherwise enabled (though consider just using --color=always to enable color for the whole output, including this format and anything else git might color). auto alone (i.e. %C(auto)) will turn on auto coloring on the next placeholders until the color is switched again.
  
  %m
  
  left (<), right (>) or boundary (-) mark
  
  %w([<w>[,<i1>[,<i2>]]])
  
  switch line wrapping, like the -w option of git-shortlog[1].
  
  %<(<N>[,trunc|ltrunc|mtrunc])
  
  make the next placeholder take at least N columns, padding spaces on the right if necessary. Optionally truncate at the beginning (ltrunc), the middle (mtrunc) or the end (trunc) if the output is longer than N columns. Note that truncating only works correctly with N >= 2.
  
  %<|(<N>)
  
  make the next placeholder take at least until Nth columns, padding spaces on the right if necessary
  
  %>(<N>), %>|(<N>)
  
  similar to %<(<N>), %<|(<N>) respectively, but padding spaces on the left
  
  %>>(<N>), %>>|(<N>)
  
  similar to %>(<N>), %>|(<N>) respectively, except that if the next placeholder takes more spaces than given and there are spaces on its left, use those spaces
  
  %><(<N>), %><|(<N>)
  
  similar to %<(<N>), %<|(<N>) respectively, but padding both sides (i.e. the text is centered)
- Placeholders that expand to information extracted from the commit:
  %H
  
  commit hash
  
  %h
  
  abbreviated commit hash
  
  %T
  
  tree hash
  
  %t
  
  abbreviated tree hash
  
  %P
  
  parent hashes
  
  %p
  
  abbreviated parent hashes
  
  %an
  
  author name
  
  %aN
  
  author name (respecting .mailmap, see git-shortlog[1] or git-blame[1])
  
  %ae
  
  author email
  
  %aE
  
  author email (respecting .mailmap, see git-shortlog[1] or git-blame[1])
  
  %al
  
  author email local-part (the part before the @ sign)
  
  %aL
  
  author local-part (see %al) respecting .mailmap, see git-shortlog[1] or git-blame[1])
  
  %ad
  
  author date (format respects --date= option)
  
  %aD
  
  author date, RFC2822 style
  
  %ar
  
  author date, relative
  
  %at
  
  author date, UNIX timestamp
  
  %ai
  
  author date, ISO 8601-like format
  
  %aI
  
  author date, strict ISO 8601 format
  
  %as
  
  author date, short format (YYYY-MM-DD)
  
  %ah
  
  author date, human style (like the --date=human option of git-rev-list[1])
  
  %cn
  
  committer name
  
  %cN
  
  committer name (respecting .mailmap, see git-shortlog[1] or git-blame[1])
  
  %ce
  
  committer email
  
  %cE
  
  committer email (respecting .mailmap, see git-shortlog[1] or git-blame[1])
  
  %cl
  
  committer email local-part (the part before the @ sign)
  
  %cL
  
  committer local-part (see %cl) respecting .mailmap, see git-shortlog[1] or git-blame[1])
  
  %cd
  
  committer date (format respects --date= option)
  
  %cD
  
  committer date, RFC2822 style
  
  %cr
  
  committer date, relative
  
  %ct
  
  committer date, UNIX timestamp
  
  %ci
  
  committer date, ISO 8601-like format
  
  %cI
  
  committer date, strict ISO 8601 format
  
  %cs
  
  committer date, short format (YYYY-MM-DD)
  
  %ch
  
  committer date, human style (like the --date=human option of git-rev-list[1])
  
  %d
  
  ref names, like the --decorate option of git-log[1]
  
  %D
  
  ref names without the " (", ")" wrapping.
  
  %(describe[:options])
  
  human-readable name, like git-describe[1]; empty string for undescribable commits. The describe string may be followed by a colon and zero or more comma-separated options. Descriptions can be inconsistent when tags are added or removed at the same time.
  
  tags[=<bool-value>]: Instead of only considering annotated tags, consider lightweight tags as well.
  
  abbrev=<number>: Instead of using the default number of hexadecimal digits (which will vary according to the number of objects in the repository with a default of 7) of the abbreviated object name, use <number> digits, or as many digits as needed to form a unique object name.
  
  match=<pattern>: Only consider tags matching the given glob(7) pattern, excluding the "refs/tags/" prefix.
  
  exclude=<pattern>: Do not consider tags matching the given glob(7) pattern, excluding the "refs/tags/" prefix.
  
  %S
  
  ref name given on the command line by which the commit was reached (like git log --source), only works with git log
  
  %e
  
  encoding
  
  %s
  
  subject
  
  %f
  
  sanitized subject line, suitable for a filename
  
  %b
  
  body
  
  %B
  
  raw body (unwrapped subject and body)
  
  %N
  
  commit notes
  
  %GG
  
  raw verification message from GPG for a signed commit
  
  %G?
  
  show "G" for a good (valid) signature, "B" for a bad signature, "U" for a good signature with unknown validity, "X" for a good signature that has expired, "Y" for a good signature made by an expired key, "R" for a good signature made by a revoked key, "E" if the signature cannot be checked (e.g. missing key) and "N" for no signature
  
  %GS
  
  show the name of the signer for a signed commit
  
  %GK
  
  show the key used to sign a signed commit
  
  %GF
  
  show the fingerprint of the key used to sign a signed commit
  
  %GP
  
  show the fingerprint of the primary key whose subkey was used to sign a signed commit
  
  %GT
  
  show the trust level for the key used to sign a signed commit
  
  %gD
  
  reflog selector, e.g., refs/stash@{1} or refs/stash@{2 minutes ago}; the format follows the rules described for the -g option. The portion before the @ is the refname as given on the command line (so git log -g refs/heads/master would yield refs/heads/master@{0}).
  
  %gd
  
  shortened reflog selector; same as %gD, but the refname portion is shortened for human readability (so refs/heads/master becomes just master).
  
  %gn
  
  reflog identity name
  
  %gN
  
  reflog identity name (respecting .mailmap, see git-shortlog[1] or git-blame[1])
  
  %ge
  
  reflog identity email
  
  %gE
  
  reflog identity email (respecting .mailmap, see git-shortlog[1] or git-blame[1])
  
  %gs
  
  reflog subject
  
  %(trailers[:options])
  
  display the trailers of the body as interpreted by git-interpret-trailers[1]. The trailers string may be followed by a colon and zero or more comma-separated options. If any option is provided multiple times the last occurrence wins.
  
  key=<key>: only show trailers with specified <key>. Matching is done case-insensitively and trailing colon is optional. If option is given multiple times trailer lines matching any of the keys are shown. This option automatically enables the only option so that non-trailer lines in the trailer block are hidden. If that is not desired it can be disabled with only=false. E.g., %(trailers:key=Reviewed-by) shows trailer lines with key Reviewed-by.
  
  only[=<bool>]: select whether non-trailer lines from the trailer block should be included.
  
  separator=<sep>: specify a separator inserted between trailer lines. When this option is not given each trailer line is terminated with a line feed character. The string <sep> may contain the literal formatting codes described above. To use comma as separator one must use %x2C as it would otherwise be parsed as next option. E.g., %(trailers:key=Ticket,separator=%x2C ) shows all trailer lines whose key is "Ticket" separated by a comma and a space.
  
  unfold[=<bool>]: make it behave as if interpret-trailer’s --unfold option was given. E.g., %(trailers:only,unfold=true) unfolds and shows all trailer lines.
  
  keyonly[=<bool>]: only show the key part of the trailer.
  
  valueonly[=<bool>]: only show the value part of the trailer.
  
  key_value_separator=<sep>: specify a separator inserted between trailer lines. When this option is not given each trailer key-value pair is separated by ": ". Otherwise it shares the same semantics as separator=<sep> above.

Note

Some placeholders may depend on other options given to the revision traversal engine. For example, the %g* reflog options will insert an empty string unless we are traversing reflog entries (e.g., by git log -g). The %d and %D placeholders will use the "short" decoration format if --decorate was not already provided on the command line.

The boolean options accept an optional value [=<bool-value>]. The values true, false, on, off etc. are all accepted. See the "boolean" sub-section in "EXAMPLES" in git-config[1]. If a boolean option is given with no value, it’s enabled.

If you add a + (plus sign) after % of a placeholder, a line-feed is inserted immediately before the expansion if and only if the placeholder expands to a non-empty string.

If you add a - (minus sign) after % of a placeholder, all consecutive line-feeds immediately preceding the expansion are deleted if and only if the placeholder expands to an empty string.

If you add a ` ` (space) after % of a placeholder, a space is inserted immediately before the expansion if and only if the placeholder expands to a non-empty string.

tformat:

The tformat: format works exactly like format:, except that it provides "terminator" semantics instead of "separator" semantics. In other words, each commit has the message terminator character (usually a newline) appended, rather than a separator placed between entries. This means that the final entry of a single-line format will be properly terminated with a new line, just as the "oneline" format does. For example:
```
$ git log -2 --pretty=format:%h 4da45bef \
  | perl -pe '$_ .= " -- NO NEWLINE\n" unless /\n/'
4da45be
7134973 -- NO NEWLINE

$ git log -2 --pretty=tformat:%h 4da45bef \
  | perl -pe '$_ .= " -- NO NEWLINE\n" unless /\n/'
4da45be
7134973
```
In addition, any unrecognized string that has a % in it is interpreted as if it has tformat: in front of it. For example, these two are equivalent:
```
$ git log -2 --pretty=tformat:%h 4da45bef
$ git log -2 --pretty=%h 4da45bef
```