TextDiff Pro Free · Local · Private
LIVE
Original 0 words · 0 chars
Drop file here
Modified 0 words · 0 chars
Drop file here

Free Online Text Diff & Comparison Tool

TextDiff Pro is a free, instant text comparison tool. Paste two pieces of text — documents, code, emails, articles — and see every difference highlighted side-by-side in real time. No login, no uploads, no limits. Everything runs privately in your browser.

Features

  • Real-time diff — results update as you type with auto-compare mode.
  • Word-level diff — individual added and removed words are highlighted green and red.
  • Character-level diff — see exactly which characters changed inside a word.
  • Line-level diff — compare entire lines, ideal for code and structured text.
  • Similarity score — percentage match shown with a visual ring indicator.
  • Side-by-side & unified view — switch between split and unified diff layouts.
  • Ignore case / whitespace — optional flags for flexible comparison.
  • Export diff — download as HTML, plain text, JSON, or Markdown.
  • Drag & drop files — load .txt, .md, .json, .js, .php and more.
  • Dark & light theme — with automatic system preference detection.
  • 100% private — your text never leaves your browser.

How to Use

  1. Paste your original text into the left editor.
  2. Paste your modified text into the right editor.
  3. Click Compare Texts or enable Auto-compare to see differences instantly.
  4. Added words appear highlighted green. Removed words appear highlighted red.
  5. Use Word / Char / Line mode to control diff granularity.
  6. Navigate between changes with the ← → buttons in the stats bar.
  7. Export your results in HTML, TXT, JSON or Markdown format.

Frequently Asked Questions

Is TextDiff Pro free?

Yes, completely free. No account, no subscription, no usage limits. Free forever.

Is my text private?

Yes. All processing happens in your browser with JavaScript. Your text is never sent to any server.

What types of text can I compare?

Any plain text — articles, essays, code, contracts, emails, JSON, CSV, Markdown, HTML, or any other text-based content.

What is the difference between word, character and line mode?

Word mode highlights individual words that were added or removed. Character mode goes deeper and highlights the exact characters that changed. Line mode compares entire lines — useful for code diffs.

Can I compare files instead of pasting text?

Yes. Click the file icon in either editor or drag and drop a .txt, .md, .json, .js, .php, .html or similar text file directly onto the editor.

How is similarity percentage calculated?

Similarity is calculated as the ratio of unchanged characters to the total characters in the longer of the two texts, expressed as a percentage.

Who Uses a Text Diff Tool?

TextDiff Pro is used daily by writers, developers, students, legal teams and businesses worldwide to track and verify changes in text.

✍️

Writers & Editors

Compare draft versions of articles, blogs or books. See exactly what changed between revisions without reading the entire document again.

💻

Developers

Quickly diff code snippets, config files, JSON responses, or API outputs without opening a full IDE. Spot regressions in seconds.

🎓

Students & Teachers

Detect plagiarism or unintended copying between essays. Compare assignment submissions to find common phrases and differences.

⚖️

Legal & Compliance

Compare contract versions, terms of service updates, or policy documents. Identify every added, removed or changed clause instantly.

🌐

Translators

Compare source and translated texts or two translation variants. Ensure nothing was skipped or mistakenly added during translation.

📊

SEO & Content Teams

Compare page copies before and after edits. Track keyword additions, sentence changes and ensure brand guidelines are maintained.

Understanding Diff Modes

TextDiff Pro gives you three powerful modes to control exactly how differences are detected and displayed.

Word

Word-Level Diff

The default mode. Each word is treated as a single unit. Added words are highlighted green, removed words red. Perfect for comparing paragraphs, articles, emails and general text where you care about which words changed.

Original
The quick brown fox
Modified
The slow brown fox
Character

Character-Level Diff

Goes deeper than words. Every individual character is compared. Ideal when you need to find small typos, changed punctuation, or subtle edits like a missing letter inside a word.

Original
testing
Modified
esting
Line

Line-Level Diff

Each line is treated as a single unit. An entire line is highlighted if anything on it changed. This is the standard mode used by Git, GitHub and most code review tools.

Original
version: 1.0
Modified
version: 2.0

Tips & Tricks

Get more out of TextDiff Pro with these power-user features.

01

Use Auto-Compare for Live Editing

Enable the Auto-compare toggle and the diff updates in real time as you type — no need to click Compare each time. Results appear within 350ms of your last keystroke.

02

Keyboard Shortcuts Save Time

Press Ctrl+Enter to run a comparison instantly. Use Alt+↓ and Alt+↑ to jump between changes. Press Ctrl+E to open the export panel.

03

Ignore Whitespace for Clean Diffs

When comparing code that was reformatted or text with inconsistent spacing, enable Ignore Whitespace to focus only on meaningful content changes.

04

Ignore Case for Content Review

Toggle Ignore Case when case differences don't matter — for example when comparing user-generated content that may have inconsistent capitalisation.

05

Drag & Drop Files Directly

You don't need to open a file and copy-paste. Drag any .txt, .md, .json, .js, .php, .html or similar file directly onto either editor.

06

Export as HTML for Sharing

Click Export → HTML File to download a fully self-contained HTML page with all the colours and highlights intact. Share it with colleagues by email or upload it anywhere.

07

Export as JSON for Automation

The JSON export contains the full diff op stream with stats. Use it in your own scripts, CI pipelines or applications to process diff results programmatically.

08

Switch to Unified View for Code Review

The Unified view shows both sides merged into one panel with + and − prefix markers — exactly like git diff. Great for developers reviewing patches.

TextDiff Pro is part of a growing suite of free developer and productivity tools at techsolexpert.com.

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