ToolSnap
Developer Tool

Diff Checker

Compare two texts side by side and instantly see every line that was added, removed, or kept the same.

Original 0 lines
Changed 0 lines

Paste both texts above and click Compare to see the differences.

Tip: press ⌘ + ↵ when ready.

How to use the Diff Checker

  1. Paste the original text in the left panel and the changed text in the right panel.
  2. Click Compare (or press ⌘ ↵) to see the differences highlighted.
  3. Choose between Unified view (both texts interleaved) and Split view (side by side) using the toggle.
  4. The stats bar shows the number of added, removed and unchanged lines.
  5. Click Clear to reset both panels and start a new comparison.

Common use cases

  • Code review. Paste two versions of a function or config file to quickly see what changed between commits without opening a Git client.
  • Document editing. Compare two drafts of a contract, article or email to verify which sentences were added, removed or reworded.
  • Configuration files. Spot differences between two .env, JSON, YAML or TOML files when debugging environment issues.
  • Log comparison. Paste two server log snapshots to identify new error lines or changed status codes.
  • Translation review. Compare the source text and translation side by side to verify no sentences were skipped or duplicated.

Limitations

  • Each side is limited to 2,000 lines or 200 KB. For larger files, use a local tool like diff or your IDE's built-in diff viewer.
  • The comparison is line-by-line, not word-by-word. Inline word-level changes within a line are not highlighted separately.
  • The tool works with plain text only. Binary files (images, PDFs, Word documents) cannot be compared here.

Frequently asked questions

What is a diff checker?
A diff checker compares two texts and highlights differences — added lines (green), removed lines (red), and unchanged lines. Widely used by developers to review code changes.
Is my text stored or shared?
No. All comparison happens locally in your browser using JavaScript. No text is sent to any server.
Can I compare code with this tool?
Yes. Works with any plain text: code, config files, logs, documents, CSV, JSON, and more.
What do the colors mean?
Green lines were added in the new version. Red lines were removed from the original. Lines with no color are unchanged.

Related tools

Tip Calculator Word Counter Base64 Encoder / Decoder JSON Formatter Hex to RGB Password Generator Aspect Ratio Calculator UUID Generator Unix Timestamp Converter URL Encoder / Decoder Lorem Ipsum Generator BMI Calculator Markdown Previewer Color Contrast Checker Random Number Generator Percentage Calculator Fantasy Name Generator Age Calculator Salary to Hourly Calculator Online Stopwatch Tuner Rhythm Trainer Online Metronome