Viewing History

One of Git's most powerful features is its ability to show you the complete history of a project. You can see every commit ever made, who made it, when, and exactly what changed. This lesson covers the tools Git provides for exploring that history.

The Basic Log

The git log command shows the commit history in reverse chronological order (newest first):

git log

Each entry shows the full SHA hash, author, date, and commit message. Press q to exit the pager.

Compact Log Format

For a condensed overview, use the --oneline flag:

git log --oneline

Each commit appears on a single line with an abbreviated SHA and the commit subject. This is ideal for getting a quick sense of recent activity.

Graph View

When working with branches, the --graph flag draws an ASCII art representation of the branch and merge history:

git log --oneline --graph --all

The --all flag includes all branches, not just the current one.

Filtering the Log

Git log supports powerful filtering options:

# Commits by a specific author
git log --author="Alice"

# Commits from the last two weeks
git log --since="2 weeks ago"

# Commits affecting a specific file
git log -- README.md

# Search commit messages for a keyword
git log --grep="login"

Viewing a Specific Commit

To see the full details of a single commit — including the diff it introduced — use git show:

git show abc1234

Replace abc1234 with any abbreviated or full SHA. You can also use HEAD to refer to the most recent commit:

git show HEAD

Comparing Commits

To see what changed between two commits, use git diff with two SHAs or branch names:

git diff abc1234 def5678

Annotated Line History

git blame shows you which commit last modified each line of a file — useful for understanding why a particular piece of code was written:

git blame README.md

Searching the Entire History

To find all commits that introduced or removed a particular string anywhere in the code:

git log -S "functionName"

This is called a pickaxe search and is invaluable for tracking down when a function or variable was introduced or deleted.

The Reflog