Mastering Git Log: Essential Commands for Filtering Commits

git log is your primary tool for viewing repository history. These commands work across all Git hosting platforms (GitHub, GitLab, Gitea, etc.) and are essential for debugging, code review, and maintaining audit trails.

Basic commit listing

git log --oneline

Each commit appears as a single line with the abbreviated hash and message. Add --reverse to see oldest commits first:

git log --oneline --reverse

For full details (author, date, full message body):

git log

Press q to exit the pager. For a specific number of commits without paging:

git log --oneline -n 20

Viewing branch structure and merges

See how branches diverge and merge:

git log --graph --all --oneline

The --graph flag draws ASCII lines showing branching points. --all includes all branches, not just your current one. For more context with branch labels:

git log --graph --all --decorate --oneline

The --decorate flag labels branches and tags at each commit. For a wider, more readable graph in modern terminals:

git log --graph --all --oneline --decorate --abbrev-commit

Filtering commits by message

Search commit messages (case-insensitive by default):

git log --grep="bug fix"

Use regex patterns:

git log --grep="^Fix:" --oneline

Combine multiple patterns:

git log --grep="bug" --grep="urgent" --all-match

The --all-match flag requires all patterns to match in a single commit.

Filtering by author

git log --author="eric"

Matches against author name or email. Use regex for flexible matching:

git log --author="eric|sarah" --oneline

Filtering by date range

git log --since="2025-01-01" --until="2025-12-31"

Supported date formats include ISO (2025-01-15), relative (2.weeks.ago, 1.month.ago), or Unix timestamps.

Filtering by file or directory

See only commits affecting specific paths:

git log -- path/to/file
git log -- src/components/

Combine with other filters:

git log --oneline --since="2024-06-01" -- src/api/

This is crucial for understanding when specific code changed and tracing feature history.

Filtering by content changes

Find commits where specific code was added or removed:

git log -S "function_name"

This finds commits where function_name was added or deleted, not just mentioned in commit messages. Use -G for regex pattern matching in diffs:

git log -G "const.*handler.*=" -- src/

Performance with large repositories

Limit history scope in monorepos and large codebases:

git log --oneline -n 50

Show recent changes to a specific subtree:

git log --oneline -n 100 -- apps/api/

For sparse checkouts with git config core.sparseCheckout true, your history still includes the full tree, but filtering to relevant directories speeds up searches.

If you regularly query a large monorepo, consider shallow clones during initial setup:

git clone --depth=1 <repo-url>

Then fetch full history as needed for specific branches.

Custom formatted output

Generate structured output for scripting or reporting:

git log --format="%h %s %an %ad" --date=short

Useful format fields:

• %h — abbreviated commit hash
• %H — full commit hash
• %s — subject line
• %b — message body
• %an — author name
• %ae — author email
• %ad — author date
• %ar — author date (relative)

Export as pipe-delimited for CSV processing:

git log --format="%H|%s|%an|%ad" --date=iso > commits.txt

For JSON-like output (pipe-delimited):

git log --format="%H%n%s%n%an%n%ad" --date=iso | paste -sd '|' - - - -

Viewing commit details

See what changed in a specific commit:

git show <commit-hash>

Show only file statistics (files changed, insertions/deletions):

git show --stat <commit-hash>

Compare two commits:

git log <commit1>..<commit2> --oneline

This shows commits reachable from commit2 but not from commit1.

Practical workflows

Code review of a feature branch:

git log --oneline main..feature-branch

Shows commits on feature-branch not yet merged to main.

What shipped between releases:

git log --oneline v1.0.0..v1.1.0

Lists commits between two tags.

Check your own recent work:

git log --author="$(git config user.name)" --oneline -20

See commits by multiple team members:

git log --oneline --all --since="1.week.ago" --author="alice|bob|carlos"

Find when a bug was introduced (bisect preparation):

git log -p --all -S "buggy_code" -- src/main.js

Shows full diffs (-p) of commits touching the buggy code.

Export recent history for audit:

git log --format="%h|%s|%an|%ai|%d" --all --since="2025-01-01" > audit_log.txt