Diff Checker

Compare two texts side-by-side. Find every difference. AI-powered explanation of what changed. Free, instant, 100% private.

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About Diff Checker

Compare two versions of text or code and instantly see what changed:

  • Side-by-side: Traditional diff view with additions and deletions
  • Inline: Unified diff format similar to git diff
  • Code-aware: Works great for source code, config files, JSON, and prose

🔒 All comparison happens in your browser. Your text never leaves your device.

About Diff Checker

Compare two text blocks side by side. Find differences with line-by-line highlighting. Perfect for code review, configuration changes, document revisions, and spotting edits. All processing in your browser.

Side-by-Side View

Split pane comparison with synchronized scrolling. Added lines in green, removed in red, unchanged in white.

Line-Level Diffs

Word-level highlighting within changed lines. See exactly what changed — not just which lines differ.

Unified Diff Output

Get standard unified diff format output. Copy-paste into git commits, code reviews, or documentation.

100% Private

Text comparison runs locally. No uploads — safe for proprietary code, configs, and sensitive documents.

📋 Common Use Cases

Reviewing Code Changes

Paste two versions of a source file side by side to review exactly which lines were added, removed, or modified before committing.

Comparing Configuration Files

Diff two versions of a config file to quickly identify environment-specific changes or accidentally-overwritten settings.

Tracking Document Revisions

Compare draft versions of a document to verify edits were applied correctly and nothing was lost between revisions.

Validating Generated Output

Diff the expected output against the actual result from a code generator or template system to catch discrepancies.

🪜 How to Use This Tool

  1. Paste the original version
    Copy the first version of your text into the left editor panel as the baseline for comparison.
  2. Paste the modified version
    Copy the second version into the right panel to compare against the original.
  3. View the diff instantly
    Added lines highlight in green, removed lines in red, and modified sections show a mixed pattern for quick scanning.
  4. Toggle unified or split view
    Switch between a side-by-side diff and a unified inline view depending on your preference for reviewing changes.

📚 Related Guides

Frequently Asked Questions

Are these dev tools free?▼
Yes. All dev tools are completely free. No signup, no account.
Is my data sent to a server?▼
No. Base64 encoding, URL encoding, JWT decoding, hash generation, and regex testing all happen in your browser. Your tokens and secrets stay on your device.
Can I decode JWTs safely?▼
Yes. JWT decoding happens entirely in your browser. The token never leaves your device. Only the header and payload are decoded — signatures are not verified server-side.

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