Diff Checker

Free Diff Checker — Compare Two Texts Side by Side

Whether you are reviewing code changes, comparing document revisions, verifying configuration file edits, or checking what changed between two versions of any text, a diff checker instantly highlights exactly what is different. This free Diff Checker compares any two pieces of text side by side with line-level and word-level highlighting — showing added content in green, removed content in red, and unchanged content in gray.

Paste the original text on the left and the modified text on the right. Click Compare to see a highlighted diff view showing every addition, deletion, and change. Toggle between line mode (highlights full lines) and word mode (highlights only changed words within lines) depending on how granular you need the comparison to be.

Diff checking is a foundational developer workflow — version control systems like Git use diff algorithms internally to track all code changes. Understanding diff output is an essential skill for any programmer or technical writer working with versioned content.

Diff Checker Use Cases

Code review. Compare code before and after refactoring to verify only intended changes were made. Catch unintentional modifications or merge conflicts.

Document revision. Track changes between versions of legal documents, contracts, articles, and reports without track-changes features.

Configuration comparison. Compare server config files, JSON configs, or environment files between environments (dev/staging/production) to find discrepancies.

Content verification. Verify that translated content matches structure, that copied content was not accidentally modified, or that API responses match expected schemas.

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Frequently Asked Questions