Text Diff / Compare
Compare two texts side by side and highlight the differences.
How to Use the Text Diff / Compare Tool
Paste your original text in the left box and the modified version in the right box, then click Compare. The diff output shows each line color-coded:
- Green (+) — lines that were added in the modified text.
- Red (-) — lines that were removed from the original text.
- Gray — lines that are unchanged between both versions.
Extra Controls
- Swap — switches the original and modified texts so you can view the diff in reverse.
- Clear — empties both text areas and resets the output.
Common Use Cases
Compare two versions of a document, review code changes before committing, verify configuration file edits, or check translation differences. Everything runs in your browser — no data is uploaded.
Frequently Asked Questions
How does the diff algorithm work?
The tool uses a longest common subsequence (LCS) algorithm to compare lines. It finds the longest sequence of lines common to both texts, then marks remaining lines as added or removed.
Is my text stored or uploaded anywhere?
No. All processing happens locally in your browser. Your text never leaves your device.
Can I compare code files?
Yes. The diff output uses a monospace font and preserves indentation, making it suitable for comparing code, config files, or any structured text.
What does the Swap button do?
Swap exchanges the original and modified texts. This is useful when you want to see the diff from the opposite perspective — what was added becomes removed and vice versa.
Is there a size limit?
There is no hard limit, but very large texts (tens of thousands of lines) may slow down the comparison since it runs in your browser. For typical documents and code files the tool works instantly.
More Text Tools
Word Counter
Count words, characters, sentences, paragraphs and estimate reading time.
Open tool →Case Converter
Convert text between UPPER, lower, Title, Sentence, camelCase, snake_case and more.
Open tool →Lorem Ipsum Generator
Generate placeholder text in paragraphs, sentences or words.
Open tool →Text to Slug
Generate URL-friendly slugs from any text.
Open tool →Text Reverser
Reverse text by characters, words or lines.
Open tool →Character Counter
Count characters with platform-specific limits for Twitter, Instagram and more.
Open tool →