Compare two texts and highlight the differences.
The Text Diff Checker lets you instantly compare two blocks of text and see exactly what changed. Paste your original and updated content side by side, and the tool highlights every addition in green and every removal in red — line by line. Whether you're proofreading edits, reviewing code snippets, or auditing document revisions, this free online diff checker gives you a clear, color-coded breakdown in seconds.
A text diff checker compares two versions of text and highlights the differences between them. Lines that were removed are marked with a '-' prefix and a red background, while lines that were added are marked with a '+' prefix and a green background. Unchanged lines appear normally.
Yes. The comparison is case-sensitive by default, so 'Hello' and 'hello' are treated as different text. This matches the behavior of standard diff tools used by developers.
Absolutely. The diff viewer uses a monospace font and preserves whitespace, making it easy to compare code, configuration files, JSON, or any plain-text content line by line.
The tool uses a Longest Common Subsequence (LCS) algorithm — the same approach used by classic Unix diff utilities. It finds the maximum set of lines common to both texts, then marks everything else as added or removed, giving you an accurate and minimal diff.