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Text Diff — Free Online Diff Checker (Line, Word & Character)

Compare two blocks of text — side-by-side, inline, or unified patch. Line, word, or character granularity.

Free No signup Client-side Privacy friendly Updated
+ added - removed unchanged Computing…

How to use

  1. 1 Paste the original text on the left, the modified text on the right.
  2. 2 Pick a view — side-by-side, inline, or unified patch.
  3. 3 Pick a granularity — line, word, or character.
  4. 4 Stats and color-coded output update live.

Why use this tool

  • Powered by Google's <code class="font-mono text-xs">diff-match-patch</code> — the same algorithm used in many production diff tools.
  • Pure client-side — your text never leaves the browser.
  • Multiple views — pick the format that fits your review.
  • Unified patch output is paste-ready for <code class="font-mono text-xs">patch -p0</code>.

Frequently asked questions

What's the difference between line, word, and character granularity?

Line groups changes by full lines (cleanest for code review). Word highlights edited words within a paragraph. Character is finest-grained — useful for small typo fixes.

Can I export the diff as a patch file?

Yes — pick the Patch view. The output uses the diff-match-patch unified format, compatible with most patch utilities.

Need to compare JSON or XML?

Use <a class="text-brand-600 hover:underline" href="/json-diff">JSON Diff</a> for structural JSON comparison.

Related tools?

<a class="text-brand-600 hover:underline" href="/json-formatter">JSON Formatter</a> for cleaning input before comparing; <a class="text-brand-600 hover:underline" href="/deduplicate-lines">Deduplicate Lines</a> for list cleanup.

What is Text Diff?

A Text Diff tool compares two blocks of text and highlights the additions, deletions, and unchanged regions. Line-level diffs match the behaviour of `git diff`; word- and character-level diffs surface small edits inside long lines. Three display modes are common: side-by-side (original vs new), inline (one stream with insertions/deletions marked), and unified patch (the format git produces).

Features

Three views

Side-by-side (original vs new), inline (one stream with marks), or unified patch — the format git produces.

Line / word / character

Pick the granularity to catch a whole-line rewrite or a single-character typo.

100% private

Both texts are compared on your device and never uploaded.

Example

Input

The quick brown fox
The quick red fox

Output

  The quick
- brown
+ red
  fox

Common use cases

  1. 1

    Review document edits

    Compare two versions of a document to see exactly what changed.

  2. 2

    Inspect config drift

    Diff two config files to find the line that differs between environments.

  3. 3

    Generate a patch

    Produce a unified diff to share, or apply later as a git patch.

How Text Diff compares to alternatives

Text Diff versus typical browser and desktop alternatives — features compared at a glance.
Feature Zerethon Tools Typical online tools Desktop apps
Side-by-side view Yes Yes Yes
Inline view Yes Sometimes Yes
Unified patch output Yes Rarely Yes
Line / word / character All three Line only All three
Content leaves device No Sometimes No
Free Yes Yes Often paid
Summary

Zerethon's text diff compares two blocks of text and highlights additions, deletions, and unchanged regions in your browser. Line-level diffs match the behaviour of `git diff`; word- and character-level diffs surface small edits inside long lines. Results display side-by-side, inline, or as a unified patch. Nothing is uploaded.

Category
Developer
Pricing
Free
Privacy
Browser-based
Signup
Not required

References

Privacy

Your data never leaves your browser unless explicitly stated. Text Diff runs entirely client-side — no server upload, no logging, no tracking of your input.

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