TEXT DIFF CHECKER
Compare texts side-by-side, spot differences instantly.
Everything runs locally in your browser. Your data never leaves your device - no uploads, no servers, no data transmission.
All processing happens directly on your machine using JavaScript. Close the tab and all data is released.
Comparison mode
Conversion analytics
Choose mode
Select comparison type
Input texts
Paste or upload two texts
View differences
See changes highlighted
Why choose this text diff checker?
4 modes, 16 file formats, ignore whitespace/case, similarity %, TXT/MD/DOCX export
4 comparison modes
Line-by-line, word-by-word, character-by-character, or unified view for precise difference detection.
Drag & drop file upload
Drop files directly into the editor. 16 formats: TXT, MD, CSV, JSON, XML, HTML, CSS, JS, TS, JSX, TSX, SQL, DOCX, ODT, LOG.
Split & Unified views
Side-by-side comparison or unified diff view. Choose what works best for your workflow.
Export to multiple formats
Download your diff results as TXT, Markdown, or DOCX. Share or archive comparisons easily.
Synchronized scrolling
Scroll both text panels together to keep corresponding lines aligned for easier comparison.
Color-coded changes
Visual highlighting with green for additions and red for deletions. Instantly spot every difference between two texts.
Frequently Asked Questions
Everything about comparing and analyzing text differences
What is a text diff checker?
A text diff checker compares two texts and highlights the differences between them. It shows what was added, removed, or changed.
How do I compare two texts?
Paste your original text in the left panel and modified text in the right panel. Select a comparison mode and click Compare to see the differences.
What are the different comparison modes?
Line mode compares line by line, word mode compares word by word, character mode compares character by character, and unified mode shows changes in a single view.
Can I compare code files?
Yes. Upload or paste any code files (JavaScript, Python, HTML, CSS, etc.) and the tool will highlight the differences with syntax preserved.
Can I save or export the comparison results?
Yes. Click the download button to save the diff as a text file, or use the copy button to copy the results to your clipboard.
What does ignore whitespace and ignore case do?
Ignore whitespace removes all spaces and line breaks before comparing. Ignore case makes the comparison case-insensitive (A = a).
Is my data safe with this tool?
Yes. Everything runs locally in your browser. Nothing is uploaded, nothing stored. Close the tab and all data is released.
What file formats can I upload?
16 formats: TXT, MD, CSV, TSV, JSON, XML, HTML, CSS, JS, TS, JSX, TSX, SQL, DOCX, ODT, and LOG. Just drag and drop or click upload.
Can I compare large files?
Yes. This diff checker handles texts of any size with optimized performance. For very large files (100k+ lines), comparison may take a few seconds.
Technical Details
How this text diff checker compares and analyzes differences
Diff Algorithm
This text diff checker implements the Myers diff algorithm with O(ND) time complexity, where N is the total length and D is the edit distance. The algorithm finds the shortest edit script (minimum insertions + deletions) to transform the original text into the modified version. Line-level and character-level granularity are both supported.
View Modes
The online diff checker offers side-by-side and unified diff views with synchronized scrolling. Added lines are highlighted in green, removed lines in red, and modified lines show character-level changes within the line. Line numbers, word wrap, and syntax-aware highlighting help locate changes across large documents.
Comparison Statistics
The text comparison tool calculates detailed metrics: total lines changed, additions, deletions, modifications, and similarity percentage. Word-level and character-level diff counts provide granular change analysis. Statistics update in real-time as you edit either text panel, with all processing running client-side.
Input Methods
The diff checker online supports direct text input, file upload (16 formats: TXT, MD, CSV, TSV, JSON, XML, HTML, CSS, JS, TS, JSX, TSX, SQL, DOCX, ODT, LOG), clipboard paste, and drag-and-drop. Auto-beautify formats JSON, XML, HTML, CSS, JS, and SQL on import. Export diff results as TXT, Markdown, or DOCX.