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ToolText Pro

Free Online Text Tools for Everyone

Text Diff Checker - Free Online Comparison Tool

Compare two texts and see exactly what changed. Perfect for comparing documents, code, versions, or any text content. Features multiple view modes, advanced comparison options, and detailed statistics — all processing happens securely in your browser.

Original Text

0 characters, 0 words, 0 lines

Modified Text

0 characters, 0 words, 0 lines

Enter text in both panels to see the comparison

The differences will be highlighted here

Statistics

Enter text in both panels to see comparison statistics

Comparison Mode:

Options:

View Mode:

Why Use This Text Diff Tool?

Whether you're tracking changes in documents, comparing code versions, or reviewing edits, our Text Diff Checker makes it easy to see exactly what changed. Using the industry-standard Myers' Diff Algorithm, it efficiently identifies and highlights additions, deletions, and modifications between any two texts.

After checking your differences, you can also use our Word Counter or Case Converter to further refine your text. All comparisons happen 100% in your browser — no server uploads, complete privacy, and instant results even for large files up to 50MB.

Perfect For:

Developers & Engineers

Comparing code versions, reviewing PR changes, and identifying debugging differences.

Writers & Editors

Tracking document revisions, verifying corrections, and analyzing draft updates.

Content Managers

Reviewing website copy updates and auditing localized content changes.

QA & Legal Teams

Validating text updates in contracts and verifying compliance modifications.

How It Works

Comparing your texts is simple and happens in three easy steps:

  1. Input: Paste your texts into the "Original" and "Modified" panels, or upload text files.
  2. Compare: The tool automatically calculates differences using the Myers algorithm instantly.
  3. Analyze: Review the highlighted changes using your preferred view mode and export the results.

View Mode Comparison

ModeBest ForVisual Style
Side-by-SideComparing documents visuallyTwo columns, matched lines
InlineCode reviews and PR styleSingle column, interleaved changes
Changes OnlyFinding quick modificationsFiltered list of only modified parts

Frequently Asked Questions

FAQ

A text diff/comparison tool analyzes two text documents and highlights the differences between them. It shows you exactly what was added, removed, or changed, making it easy to track edits, compare versions, or verify changes in documents, code, or any text content.

Our tool uses Myers' Diff Algorithm, a industry-standard algorithm that efficiently finds the longest common subsequence between two texts. It can compare at three levels: character-level for precise changes, word-level for readability, and line-level for structured documents and code.

Character-level: Compares every single character, showing exact positions of changes. Best for finding typos and precise edits. Word-level (recommended): Compares word by word, more readable for general text. Line-level: Compares entire lines, ideal for code comparison and version control.

You can customize comparisons with: Ignore Case (treat uppercase and lowercase as identical), Ignore Whitespace (treat multiple spaces/tabs as identical), Ignore Punctuation (focus on words only), Ignore Numbers (useful when numbers are placeholders), and Trim Line Whitespace (remove leading/trailing spaces).

Side-by-Side: Shows original and modified text in two panels, great for comprehensive comparison. Inline/Unified: Single column with changes marked inline, similar to Git diffs. Changes-Only: Displays only the parts that changed, hiding unchanged sections for faster review.

The similarity percentage shows how much of the content is identical. 90-100% means texts are very similar (green), 70-90% indicates moderate changes (yellow), and below 70% shows significant differences (red). 100% means completely identical texts.

Yes! Our tool supports files up to 50MB and handles thousands of lines efficiently. The comparison runs entirely in your browser with no server upload, ensuring privacy and fast processing even for large documents.

You can upload and compare .txt, .md, .html, .js, .css, .json, .xml, .csv, .log and other plain text files. The tool works with any UTF-8 encoded text content. You can also paste text directly or type in the text boxes.

Absolutely! All text comparison happens 100% in your browser. Nothing is uploaded to any server. Your texts never leave your computer, ensuring complete privacy and security. The tool works offline once loaded.

Yes! Your recent comparisons are automatically saved to your browser's local storage (up to 10 most recent). You can reload them anytime. You can also export results as text files or copy them to clipboard for sharing.