Diff Checker

Comparison Input
Clear
Differences found Changed

Review 3 line changes between the original and modified text, then copy the summary or share URL when you need another reviewer to see the same state.

Current preset API response contract
Original lines 5
Modified lines 6
Added lines +2
Removed lines -1
Unchanged context 4
Match rules Whitespace and letter case both count as differences.
Line-by-Line Diff +2 / -1 / 4 unchanged
Original Modified Content
1 1 {
2 2 "status": "ok",
3 3 "userId": 42,
4 "plan": "starter"
4 "plan": "pro",
5 "region": "us-east-1"
5 6 }
Use the live diff checker, then continue the automation review

Stay on this page for the line-by-line comparison, then jump into the matching guide or the related cron, regex, and Markdown explainers when the task expands.

Read the diff guide Open Automation/Text Ops hub
Automation/Text Ops hub
Return to the cluster chooser for cron, regex, Markdown, and diff workflows.
Cron debugging guide
Switch to cron when the diff is comparing scheduler expressions.
Regex validation guide
Switch to regex when the real question is one active pattern rather than two text revisions.
Markdown preview guide
Preview the final documentation after the change review is complete.
Comparison Presets
Environment config rollout
Preset
Review a safe production config update with one changed flag and one newly enabled feature.
API response contract
Active
Compare a small JSON payload before and after a response-shape update so field additions stand out quickly.
Editorial review pass
Preset
See how a short content review reads when one sentence is tightened and a final call-to-action line is added.
What is Diff?

A diff compares two pieces of text and shows what was added, removed, or changed. It is the mechanism behind version control history, code review, and document comparison.

How Diff Works

Diff algorithms typically use techniques like Longest Common Subsequence (LCS) to find the minimal set of changes between two texts. Results show additions (new lines), deletions (removed lines), and modifications (changed lines). Advanced diffs can show character-level changes within modified lines.

Common Use Cases
  • Comparing code versions before merging
  • Reviewing configuration file changes
  • Validating document revisions
  • Debugging by comparing expected vs actual output
  • Tracking changes in data exports
Features
  • Side-by-side comparison view
  • Line-by-line difference highlighting
  • Added and removed line indicators
  • Character-level change detection
Frequently Asked Questions

What's the difference between unified and side-by-side diff?

Unified diff shows changes in a single column with +/- markers, more compact for patches. Side-by-side diff shows both versions in parallel columns, easier for visual comparison.

How can I ignore whitespace differences?

Most diff tools offer options to ignore whitespace changes. This is useful when comparing code with different formatting but identical logic.