Text Diff Checker
Enter text in both panels above to see the difference
The two texts are identical
Free online text diff checker and comparison tool. Compare two texts with side-by-side or unified view. Supports word-level, line-level, and character-level diff. Added content highlighted in green, removed in red. Features swap, clear, sample text, copy diff, ignore case, and ignore whitespace options. All processing runs locally in your browser — no data upload.
What is Text Diff?
Text diff (short for difference) is a comparison between two texts that shows what has been added, removed, or changed. It is widely used in version control systems, code review, document editing, and content management to track changes between versions.
Tips & Tricks
Three Comparison Levels
Switch between word-level, line-level, and character-level comparison. Word level is best for prose text, line level for structured data or code, and character level for spotting small typos and spelling changes.
Two View Modes
Side-by-side view shows both texts aligned vertically for easy scanning. Unified view interleaves additions and deletions in a single column, which can be more compact for large diffs.
Privacy & Security
All text comparison is performed entirely in the browser. Your text never leaves your device. No data is uploaded to any server. Ideal for comparing sensitive documents, source code, or confidential information.
Common Use Cases
Code Review
Compare code changes between versions
Document Editing
Track edits in articles and documents
Data Validation
Spot differences in data exports and CSV files
Plagiarism Check
Quickly check for copied or rewritten content
Configuration Change
Compare old and new config files
Learning & Reference
See before-and-after changes in tutorials
FAQ
What is a text diff checker?
A text diff checker is a tool that compares two texts and highlights the differences between them. It shows what content was added (highlighted in green), removed (highlighted in red), and what remained unchanged. This is useful for code reviews, document editing, tracking changes, and verifying modifications.
How does word-level diff differ from line-level diff?
Word-level diff breaks the text into individual words and compares them, which is best for prose and natural language editing — it shows exactly which words were changed within a sentence. Line-level diff compares entire lines at once, which is ideal for structured data like code or CSV files. Character-level diff compares individual characters and is useful for spotting small typos.
Is my data safe when using this tool?
Yes. All text comparison is performed entirely in your browser using JavaScript. Your text never leaves your device and is never uploaded to any server. This tool is completely safe for comparing sensitive documents, source code, passwords, or any confidential information.
What is the difference between Side-by-Side and Unified view?
Side-by-side view displays the original and modified texts in two parallel columns with the differences aligned. Unified view merges both texts into a single column, showing removed lines prefixed with a minus sign (−) and added lines prefixed with a plus sign (+). Side-by-side is generally easier to read for large documents, while unified view is more compact and familiar for developers.
How should I use the Swap button?
The Swap button exchanges the content of the Original and Modified text boxes. This is useful when you accidentally pasted the texts in the wrong order, or when you want to verify the diff from the opposite direction (showing what was reverted rather than what was changed).
What does Ignore Case do?
When Ignore Case is enabled, the comparison treats uppercase and lowercase letters as identical. For example, 'Hello' and 'hello' would be considered the same. This is useful when comparing text where capitalization differences are not meaningful, such as verifying content while ignoring formatting differences.
Can I compare large texts?
Yes, the tool can handle large texts efficiently. The diff algorithm runs entirely in your browser and works well with documents of several thousand lines. However, for extremely large files (100,000+ words), there may be a brief processing delay. If you need to compare very large files, we recommend using line-level mode and disabling word-level comparison.