Text Diff

Compare two texts side-by-side with word-level highlighting. Find differences, track changes, and review document revisions.

What It Does

Text Diff (Text Comparison) tool compares two text documents side-by-side and highlights differences at the word, line, or character level. It shows additions (content in second text but not first), deletions (content in first text but not second), and modifications (changed content). The tool uses advanced diff algorithms (similar to git diff) to find the most efficient set of changes between texts. It displays results in unified view (merged with +/- indicators) or split view (side-by-side comparison). Essential for reviewing document revisions, comparing code versions, tracking changes in contracts or legal documents, identifying what changed between file versions, and quality assurance for content updates.

Key Features:

  • Side-by-side comparison with synchronized scrolling
  • Word-level, line-level, and character-level diff granularity
  • Addition/deletion/modification highlighting with color coding
  • Unified diff view (merged) or split view (side-by-side)
  • Ignore whitespace option for cleaner comparisons
  • Case-sensitive or case-insensitive comparison
  • Diff statistics: additions count, deletions count, changes summary
  • Export diff in various formats (unified diff, HTML, PDF)

How To Use

Paste your original text in the left panel and the modified text in the right panel, select comparison options, and view highlighted differences showing exactly what changed.

1

Enter Original and Modified Text

Paste your original text (version 1, old version) in the left input panel. Paste the modified text (version 2, new version) in the right panel. These could be document revisions, code versions, email drafts, contract revisions, or any text you want to compare. The tool works with documents of any size from short paragraphs to entire files.

2

Configure Comparison Options

Choose comparison granularity: "Line-by-Line" (shows which lines changed—best for code and structured text), "Word-by-Word" (highlights individual word changes—best for prose and documents), or "Character-by-Character" (shows every character difference—best for finding typos). Select "Ignore Whitespace" to focus on content changes ignoring spacing, or "Case Insensitive" to ignore capitalization differences.

3

Review Highlighted Differences

The tool highlights changes with color coding: green background for additions (new content in version 2), red background for deletions (removed from version 1), and yellow for modifications. Switch between split view (side-by-side) for easy visual comparison or unified view (merged with +/- symbols) for git-style diff format. Review statistics showing total additions, deletions, and percentage of change. Export or save diff results if needed.

Benefits

Document Review: Instantly see what changed between document drafts without reading both versions entirely
Code Review: Compare code versions to understand what was modified, similar to git diff but with better visualization
Contract Verification: Ensure legal contracts, agreements, or proposals have only approved changes
Translation Checking: Compare original and translated texts to verify completeness and accuracy
Quality Assurance: Verify content updates match requirements and no unintended changes were made
Plagiarism Detection: Compare texts to identify copied sections or significant similarities
Version Control: Track changes over time when version control systems aren't available

Use Cases

Code Change Review and Version Comparison

Compare two versions of source code files to see exactly what changed before committing, merging, or deploying. Paste the old code version on left and new version on right. Use line-by-line comparison with "Ignore Whitespace" enabled to focus on code logic changes rather than formatting. This is valuable for: reviewing pull requests without git (email-based code sharing), comparing code before/after refactoring to verify behavior unchanged, checking what changed in downloaded file versions, and understanding updates in library code. Green highlights show added code (new functions, lines), red shows deleted code, yellow shows modifications. Much faster than reading both versions separately.

Legal Document and Contract Revision Tracking

Compare contract versions, legal agreements, or policy documents to ensure only approved changes were made and no clauses were unintentionally modified or removed. Before signing updated contracts, paste original version and revised version. Use word-by-word comparison with case-sensitive option. Carefully review all yellow (modified) and red (deleted) highlights—these are critical changes that may affect legal terms. Green (additions) shows new clauses. This prevents: signing contracts with hidden unfavorable changes, missing important clause modifications, accepting documents with unauthorized edits. Essential for lawyers, business professionals, and anyone reviewing contracts, NDAs, employment agreements, or service terms before signing.

Content Updates and Web Copy Verification

Verify that website content updates, marketing copy changes, or CMS edits match approved revisions and copywriter intent. Before publishing, compare current live version (copy from website) with proposed new version (from copywriter or stakeholder). Use word-by-word comparison to catch: typos introduced during editing, unintentional deletions of important information, changes to URLs or CTAs that weren't approved, formatting or style inconsistencies. This QA step prevents embarrassing typos on live sites, ensures SEO keywords weren't accidentally removed, and verifies all requested changes were implemented. Especially important for high-visibility pages (homepage, landing pages) or regulated content (medical, financial, legal disclaimers).

Translation Verification and Completeness Check

Compare original text with translated version to ensure all content was translated (no missed sections) and formatting/structure was preserved. Paste original English (or source language) on left, translation on right. While words won't match (different languages), structure should align: same number of paragraphs, similar line breaks, equivalent headings. Use line-by-line view to verify: every paragraph has translation, no sections were skipped, placeholders like {NAME} or URLs are preserved, formatting (bold, italics) matches. This catches: incomplete translations where translator missed paragraphs, merged or split paragraphs affecting readability, removed formatting affecting emphasis, omitted important details. Essential for website translations, document localization, and product descriptions in multiple languages.

Academic Writing and Plagiarism Checking

Compare student submissions to detect copied content, verify revisions between drafts, or check if content was reused from previous assignments. Paste original source or earlier draft on left, current submission on right. Word-by-word comparison highlights: exactly matching sections (potential plagiarism), paraphrased content (yellow modifications—some rewording), completely original content (no matches). This helps: educators identify copied content, students verify their revisions improved drafts, researchers ensure proper paraphrasing not copying, writers confirm rewrites sufficiently differ from sources. Note: For comprehensive plagiarism detection across internet/databases, use specialized tools (Turnitin, Grammarly Plagiarism). Text diff is best for comparing two specific documents.

Frequently Asked Questions

1 What's the difference between line-level, word-level, and character-level diff?
Line-level diff compares entire lines: if any character in a line changed, the whole line is marked as modified. Best for code, structured data, and when you want to see which lines were affected. Word-level diff compares word-by-word: highlights specific words that changed within lines. Best for prose, documents, and when you need to see exact word changes. Character-level diff compares every character: shows precisely which characters differ, even within words. Best for finding typos, single-character changes, or subtle differences. For most document comparisons, word-level provides the best balance of detail and readability. For code, line-level is standard (matching git diff behavior). For debugging subtle issues, character-level shows maximum detail.
2 Why does "Ignore Whitespace" make my diff cleaner?
"Ignore Whitespace" treats differences in spaces, tabs, and line breaks as identical, focusing comparison on actual content. This eliminates noise from: reformatting (code auto-formatted with different indentation), copy-paste issues (trailing spaces added), line ending differences (Windows CRLF vs Unix LF), tab vs space differences. Example: without ignore whitespace, "Hello World" vs "Hello World" (two spaces) shows as different. With ignore whitespace enabled, they're treated as same. This is essential for code comparisons where you care about logic changes not formatting, document comparisons where spacing doesn't affect meaning, and comparing content from different editors or platforms. Disable it when whitespace is significant (Python indentation, Makefiles, ASCII art).
3 Can this tool replace git diff for code comparison?
This tool provides similar functionality to git diff with better visualization for non-git users, but has limitations: no context awareness (git knows about file history, renames, moves), no integration with version control, no patch file generation for applying changes, and no conflict resolution features. Use this tool for: comparing code when not using git, comparing code snippets or examples from documentation/tutorials, reviewing email-shared code changes, and understanding differences with visual highlighting. Use git diff for: actual development workflows with version control, comparing branches or commits, generating patches, code reviews integrated with git history. This tool is excellent for one-off comparisons or when sharing with non-technical stakeholders who need visual diff without git knowledge.
4 How accurate is text diff for large documents?
Modern diff algorithms (like Myers diff used by git) are highly accurate and efficient even for large documents. Accuracy concerns: complex changes with many edits may be harder to visualize clearly, very large files (>100MB) may cause browser memory issues, heavily reformatted text where almost everything changed shows as replaced rather than modified. The algorithm finds the "minimal edit distance" (smallest set of changes) between texts, which usually matches human intuition of what changed. For best results: compare similar versions (small changes), use appropriate granularity (word-level for documents, line-level for code), and enable "Ignore Whitespace" when formatting doesn't matter. For extremely large files or need for performance, use command-line tools (diff, Beyond Compare, WinMerge) which handle gigabyte files.
5 What do the different colors mean in the diff view?
Standard diff color coding: Green (or light green background) indicates additions—content present in new version but not in old version. Red (or light red/pink background) indicates deletions—content present in old version but removed in new version. Yellow or orange indicates modifications—content changed from old to new version. Gray or blue may indicate unchanged context lines (lines around changes for reference). Some tools use: strikethrough text for deletions, underline for additions, side borders or line numbers with colors. In unified view: + prefix = addition, - prefix = deletion. In split view: green on right side = addition, red on left side = deletion. These conventions follow git diff and most version control tools, making them familiar to developers and widely understood.

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