git log

Purpose

git log is used to view the commit history of a repository.

It helps you:

Identify commit hashes
Understand change history
Investigate bugs
Track feature development
Prepare for cherry-pick or revert operations

Syntax

git log

This shows:

Full commit hash
Author
Date
Commit message

Example:

commit 815991d41b0aad4754ce6bc0f85cfe7719030eea
Author: Mohan Medarametla <m**mohan@gmail.com>
Date:   Tue Feb 24 22:44:03 2026 +0530

    added java-8 index and optional

By default, git log lists all commits reachable from your current branch in reverse chronological order.

To see all branches commits:

git log –all

Most Useful Variations

1. Short One-Line Format (Recommended)

git log –oneline

Example output:

b44a233 Fix baseurl configuration
f1d7e21 trigger rebuild
591ba07 re-structured java-programs into java
815991d added java-8 index and optional
e2279e2 updated exception-handling-index.md
19435be added java 17 notes

This is the most commonly used format in real projects.

2. Show Log of a Specific Branch

git log main –oneline

Useful when you are on another branch but want to inspect main.

3. Graph View (Visual Branch Structure)

git log –graph –oneline –all

Shows branch merges visually.

Very useful for understanding:

Merge commits
Branch divergence
Rebase results

4. Log for a Specific File

git log –oneline path/to/File.java

Used when:

Investigating a bug
Backporting a fix
Finding when a file was changed

5. Show Detailed Changes in Each Commit

git log -p

Displays patch (actual code changes).

Useful for:

Code review
Understanding what changed exactly

6. Limit Number of Commits

git log -n 5

git log –oneline -5

Shows only last 5 commits.

7. Filter by Author

git log –author=”Mohan”

Useful in large team repositories.

8. Filter by Date

git log –since=”2 weeks ago”

git log –until=”2025-01-01”

Real-World Backend Use Cases

Finding commit hash for cherry-pick
Identifying when a bug was introduced
Checking what went into a release
Reviewing changes before merging
Tracking work done in a sprint

Pro-Level Combination

git log –graph –oneline –decorate –all

–graph → Visual branch structure
–oneline → Compact view
–decorate → Shows branch and tag names
–all → Includes all branches

This is extremely useful in real enterprise projects.

git log is the primary command for exploring Git history.