Paste or upload both texts into utilAZ's diff checker. The left panel holds the original, the right panel holds the modified version. Click Compare and the tool highlights additions (green), deletions (red), and modifications (yellow) line-by-line or word-by-word. You can also use command-line tools like diff file1.txt file2.txt on Linux/Mac or fc file1.txt file2.txt on Windows.

A diff tool compares two pieces of text (files, strings, or code) and identifies the exact differences between them: insertions, deletions, and modifications. It's essential for code review, version control (Git uses diff internally), document proofreading, configuration auditing, and detecting unauthorized changes.

utilAZ's Text Diff Checker is a free online tool that offers side-by-side and unified views, multiple algorithms (Myers, patience, histogram), whitespace/case ignore options, syntax highlighting, and runs entirely in your browser for privacy. No sign-up required, no file size watermarks, and works offline once loaded.

Use a diff tool with syntax-aware comparison: paste both code versions, enable 'ignore whitespace' to skip formatting noise, and choose word-level or character-level granularity. For Git repos, use git diff branch1..branch2 or git diff HEAD~1. IDE integrations (VS Code, IntelliJ) also provide inline diff with syntax highlighting.

utilAZ's diff tool processes everything client-side in your browser. No text is uploaded to any server. Your data never leaves your device, making it safe for confidential code, legal documents, and proprietary content. For maximum security, the tool works offline once the page is loaded.