Text Diff Checker
The Text Diff Checker is a comprehensive text comparison tool that compares two text versions and highlights differences including…
Click to upload original file
Supports: .txt, .md, .html, .json, .xml, .csv
Drop original file here or click to upload
Supports: .txt, .md, .html, .json, .xml, .csv
Click to upload modified file
Supports: .txt, .md, .html, .json, .xml, .csv
Drop modified file here or click to upload
Supports: .txt, .md, .html, .json, .xml, .csv
Comparison Options
Diff Legend
About Text Diff Checker
Unified Diff: Shows changes in a compact format with + and - indicators.
Side by Side: Displays original and modified text side by side for easy comparison.
Inline Changes: Highlights changes within the same line of text.
Word Level: Shows differences at the word level rather than line level.
Related tools
More from the same category
Learn more — open a section when you need details
The Text Diff Checker is a comprehensive text comparison tool that compares two text versions and highlights differences including additions (new content), deletions (removed content), and unchanged content across multiple visualization views including unified diff view (traditional side-by-side with change markers), side-by-side view (parallel columns showing original and modified), inline view (single document with inline changes), and word-level diff (precise word-by-word change highlighting). The tool provides flexible comparison options allowing you to ignore whitespace differences, toggle case sensitivity for case-insensitive comparisons, and show line numbers for precise change references in documents or code. It summarizes line counts by status (lines added, deleted, modified, unchanged) so you can quickly assess the scope and magnitude of edits before detailed review. The tool processes all comparisons entirely locally in your browser, ensuring privacy and fast performance without server uploads. Use it for reviewing content updates and revisions, inspecting code snippet changes outside full version control systems, validating translations and localization changes, documenting editorial changes during content workflows, comparing contract versions and legal document revisions, or any text comparison scenario requiring detailed change analysis and visualization for accurate document comparison and change tracking.
-
1
Paste the Original text version into the first input field or upload an original text file, then paste the Modified text version into the second input field or upload the modified file, ensuring both texts are ready for comparison with proper formatting and encoding for accurate diff calculation and change detection.
-
2
Choose Diff Type from available visualization options: Unified view (traditional diff format with change markers), Side-by-side view (parallel columns showing original and modified versions), Inline view (single document with inline changes marked), or Word-level view (precise word-by-word highlighting) depending on your preference for change visualization and detail level needed for your comparison task.
-
3
Toggle comparison options: enable "Case sensitive" for case-aware comparisons (distinguishing uppercase from lowercase) or disable for case-insensitive comparison, and enable "Ignore whitespace" to focus on substantive content changes by ignoring spaces, tabs, and line ending differences that may not be meaningful for your comparison requirements.
-
4
Enable "Show line numbers" option to display line numbers next to each line in the diff output, providing precise change references for documentation, code review comments, or communication about specific line locations where changes occurred, enabling accurate change location identification and reference.
-
5
Click "Compare" or "Generate Diff" button to process both text versions, calculate differences, apply selected comparison options, and display formatted diff output with highlighted changes, color-coded additions (typically green), deletions (typically red), and unchanged content (typically unchanged) for visual change identification.
-
6
Review the highlighted diff output in your selected view type, examining color-coded changes, line count summaries showing scope of edits (lines added, deleted, modified), and specific change locations to understand what changed between original and modified text versions for comprehensive change analysis.
-
7
Use "Copy" button to copy diff output to clipboard for immediate pasting into documents, reports, or communications, or click "Download" to save diff output as a text file for audit trails, documentation, or archival purposes requiring persistent diff records for change tracking and documentation.
-
8
For large files or documents, consider comparing sections or chunks separately to maintain browser performance, as extremely large text comparisons may slow processing, requiring section-by-section comparison or file splitting for optimal performance when comparing very large text documents exceeding browser processing limits.
Content review and editorial workflows
Compare article revisions, blog post versions, or content updates before publishing, enabling content editors to review changes, verify edits, and ensure content quality by examining what changed between draft versions and final content for editorial review and content quality assurance.
Code snippet change inspection and review
Visually inspect code changes outside full version control systems, compare code snippets for documentation, or review code modifications without accessing VCS, enabling developers to quickly identify code differences, review changes, or analyze code modifications for debugging, documentation, or code review purposes.
Localization and translation quality assurance
Verify that only intended phrases differ between original and translated versions, ensuring translations maintain structure while changing language, enabling localization QA by comparing source and translated text to confirm translation accuracy and verify that only linguistic changes occurred without unintended modifications.
Contract and legal document revision tracking
See edits clearly in contract versions, legal documents, or agreement revisions without tracked changes enabled, enabling legal professionals to identify changes, compare document versions, and document modifications in contracts or legal documents requiring clear change visualization for legal review and documentation.
Technical documentation and specification comparison
Compare technical documentation versions, specification updates, or API documentation changes to identify modifications, track documentation updates, and verify that documentation changes are accurate and complete for technical documentation maintenance and version control workflows.
Configuration file and settings comparison
Compare configuration files, settings files, or parameter files to identify differences, track configuration changes, or verify configuration updates for system administration, deployment workflows, or configuration management requiring accurate identification of configuration differences and changes.
Data validation and integrity checking
Compare data exports, database dumps, or data files to verify data consistency, identify data changes, or validate data integrity across different data versions for data quality assurance, migration verification, or data validation workflows requiring detailed data comparison and change identification.
Educational and learning applications
Compare student submissions with reference answers, compare essay revisions for educational feedback, or demonstrate text changes in educational contexts, enabling educators to provide detailed feedback, show revision examples, or assess student work through comprehensive text comparison and change visualization for educational purposes.
Use "Ignore whitespace" option to focus on substantive content changes when formatting differences (spaces, tabs, line breaks) aren't meaningful, as ignoring whitespace highlights only content changes rather than formatting variations, enabling focus on actual content modifications rather than formatting differences for efficient change review.
Select inline or word-level views to pinpoint small edits, typos, or precise character-level changes, as word-level diff provides granular change identification showing exactly which words changed, enabling precise change location and detailed change analysis for typo detection, minor edit identification, or character-level change tracking.
Save diff comparisons as text artifacts or files for audit trails, documentation, or change history, as persistent diff records enable change tracking over time, documentation of modifications, or reference for future comparisons, requiring diff output preservation for comprehensive change management and documentation workflows.
For large files, compare sections or chunks separately to maintain browser performance, as extremely large text files (over 10MB) may cause browser slowdowns or memory issues, requiring section-by-section comparison or file splitting for optimal performance when comparing very large documents or datasets.
Normalize line endings beforehand (convert to consistent line ending format: \n, \r\n, or \r) to avoid false differences, as different line ending formats (Unix, Windows, Mac) create false diffs for every line when line endings differ, requiring line ending normalization before comparison to show actual content differences rather than line ending variations.
Review diff statistics (lines added, deleted, modified) before detailed change analysis to understand change scope, as statistics provide overview of change magnitude enabling prioritization of review effort and understanding whether changes are extensive or minimal before committing time to detailed change-by-change review.
Use appropriate diff view type based on content characteristics: unified view for code, word-level view for prose, side-by-side for parallel comparison, as different view types work better for different content types (structured code vs flowing prose vs tabular data), requiring view selection matching content characteristics for optimal change visualization and efficient change identification.
Test diff output formatting before sharing or downloading, as different diff formats may have different styling, color coding, or markup that affects readability, requiring verification that diff output displays correctly with appropriate highlighting, colors, and formatting for effective change visualization and communication to recipients.
Comparing files with different line endings without normalization, when Unix (\n), Windows (\r\n), or Mac (\r) line endings create false differences for every line, causing diff to show entire files as different when only line endings differ, requiring line ending normalization before comparison to show actual content differences.
Leaving case sensitivity on when casing is irrelevant, when case-sensitive comparison flags minor capitalization differences as significant changes, causing diff to highlight irrelevant case variations instead of focusing on substantive content changes, requiring case-insensitive option when case differences aren't meaningful.
Assuming exact HTML copy preserves highlighting styles, when copied HTML from diff output loses CSS styling and color highlighting that makes differences visible, causing plain text diff output that lacks visual distinction between additions, deletions, and unchanged content, requiring download or screenshot for styled output.
Forgetting to include context when sharing unified diffs, when unified diff format shows only changed lines without surrounding context, causing confusion for recipients who need surrounding lines to understand change location and meaning, requiring context addition or alternative diff view that includes surrounding content.
Not using appropriate diff view type for content type, when unified view works for code but word-level view is better for prose, causing inefficient change detection if wrong view type is selected, requiring view selection matching content characteristics (structured code vs flowing prose vs tabular data).
Comparing extremely large files causing browser performance issues, when very large text files (over 10MB) require significant processing that slows browser, causes memory problems, or times out, requiring file splitting, section-by-section comparison, or server-side diff tools for large file comparison workflows.
Ignoring whitespace differences when they matter for code, when code formatting, indentation, or whitespace changes are significant for code correctness, causing important formatting changes to be hidden if whitespace is ignored, requiring whitespace sensitivity selection based on whether formatting matters for content type.
Not reviewing diff statistics before analyzing changes, when statistics show change scope (lines added, deleted, modified) that helps prioritize review effort, causing inefficient change analysis if large change sets aren't identified early, requiring statistics review to understand change magnitude before detailed diff review.
Assuming diff output is production-ready without validation, when diff shows what changed but doesn't verify correctness, causing errors if changed content isn't validated, requiring change review and testing to ensure modifications produce correct results and maintain intended functionality or accuracy.
Comparing files with encoding differences (UTF-8 vs UTF-16), when different character encodings create apparent differences even when content is identical, causing false diff results if encoding isn't normalized, requiring encoding conversion to common encoding (UTF-8) before comparison for accurate diff results.
Not preserving original files before using diff output for updates, when diff output is used to update files, causing loss of original content if updates are incorrect or need rollback, requiring original file preservation for restoration if diff-based updates produce unexpected results or need correction.
Mixing diff types without understanding output format differences, when unified, side-by-side, inline, and word-level views serve different purposes, causing confusion if wrong view type is selected for intended use case, requiring understanding of each view type's strengths and appropriate selection for specific comparison needs.
A lightweight line/word comparison suited for quick, local checks.
No, this tool compares text only. Convert to text first.
Use Download to save a text report, or copy HTML from the output if needed.
Check whitespace/case options and normalize line endings (\n vs \r\n).
Large inputs are possible but may be slow in-browser; split by sections.
No. Everything runs locally in your browser.
It presents human‑readable output, not a git‑compatible patch.
A simple merge helper is included; use VCS for full merges.
Copy the diff output or download the comparison as a text file.
This focuses on structural changes; syntax highlighting is not applied.
No, this tool compares two texts at a time. For multi-file comparison, compare files pairwise sequentially, or use version control systems (Git) that provide multi-file diff capabilities for comprehensive change analysis across multiple files.
The diff algorithm focuses on line-by-line and word-by-word comparison, suitable for most text comparison needs. For extremely large files or complex merging scenarios, consider using specialized version control diff tools (Git diff, Mercurial diff) that use more sophisticated algorithms optimized for code change detection and three-way merging.