Text Diff Tool Online Free
Paste two versions of any text and see every difference highlighted instantly. Line level and character level diff, side by side or unified view. Runs entirely in your browser.
Why Use a Text Diff Tool Online Free
Spotting changes between two versions of a document, config file, contract, or code snippet by eye is slow and error-prone. One changed word in a paragraph of text can take minutes to find manually.
This text diff tool online free runs the LCS algorithm in your browser to find the minimum set of changes between two texts. Deleted lines show in red. Added lines show in green. Character level mode zooms into exactly which letters changed within a line.
No server. No upload. Your text stays on your device.
What this tool does
How to compare two texts
Paste original
Paste or type the original version of your text into the left pane.
Paste modified
Paste the new version into the right pane. The diff runs automatically.
Read the diff
Green lines were added. Red lines were removed. Grey lines are unchanged.
Copy or share
Copy the unified diff output to share with teammates or save for review.
FAQ: Text Diff Tool Online Free
Yes, completely free. No account, no signup, and no payment ever required.
No. The diff algorithm runs entirely in your browser using JavaScript. Your text never leaves your device. Safe to use with confidential documents, contracts, or code.
Line level diff treats each line as one unit and marks entire lines as added or removed. Character level diff goes further and highlights the exact characters that changed within each modified line. Use character level when you need to spot small edits inside long lines.
When ignore case is on, the tool treats uppercase and lowercase letters as equal. A line that changed only in capitalization will show as unchanged. Useful when comparing text that may have been reformatted.
It collapses multiple spaces and tabs into a single space before comparing. Two lines that differ only in spacing will count as identical. Useful when comparing code that was auto-formatted or pasted from different editors.
Yes. Paste any plain text including code, JSON, YAML, SQL, HTML, or prose. The tool works on any text content.
The tool uses the Longest Common Subsequence algorithm, the same foundation used by most professional diff tools and version control systems. It finds the minimum number of changes needed to turn one text into another.