⌨️ Text Tool

Text Diff Checker Online Free

Compare two texts side by side and instantly highlight additions, deletions and changes. Perfect for comparing code, documents, or any text. No upload required.

Comparison Mode
📄 Original Text (A)
📝 Modified Text (B)

About Text Diff Checker

This free online text diff checker compares two pieces of text and highlights exactly what changed. Green lines are additions in Text B, red lines are deletions from Text A, and yellow lines are modifications. Unchanged lines are shown normally.

Uses a line-by-line LCS (Longest Common Subsequence) algorithm — the same approach used by Git's diff engine. All comparison happens in your browser — no text is sent to any server.

Updated: May 2025 · Works on Chrome, Firefox, Safari, Edge · Mobile friendly

Frequently Asked Questions

What do the colours mean?+
Green = lines added in Text B. Red = lines removed from Text A (shown with strikethrough). Yellow = lines that were modified. White = identical lines.
Is there a text length limit?+
No hard limit — the comparison runs in your browser. Very large texts (100,000+ lines) may take a second to process.
Can I compare code files?+
Yes! Paste any code — JavaScript, Python, HTML, CSS, JSON — and the diff checker will highlight exactly what changed between versions.
Is my text sent to any server?+
No. All comparison happens locally in your browser using JavaScript. Your text never leaves your device.
Done!