Code Diff Checker
Compare source code files side-by-side to highlight added and removed lines.
Line-by-Line Text Diff Comparison
Compare two text blocks side-by-side to highlight differences, additions, and deletions.
About Code Diff Checker
The Syntax-Highlighted Code Diff Checker compares two source code snippets across 50+ programming languages (JavaScript, TypeScript, Python, Go, Rust, HTML, CSS, SQL) with inline and side-by-side split diff views.
How to Use Code Diff Checker
Step 1
Paste original code into the left editor.
Step 2
Paste revised code into the right editor.
Step 3
Select programming language syntax.
Step 4
Inspect highlighted additions, deletions, and line edits.
Practical Use Cases for Code Diff Checker
Peer Code Review & Pull Request QA
Review code changes and refactored functions before submitting Git pull requests.
Configuration File & Environment Drift Comparison
Compare staging vs production configuration files and Docker compose setups.
Input & Output Examples
Comparing TypeScript Function Implementations
Snippet A: const add = (a: number, b: number) => a + b;\nSnippet B: const add = (a: number, b: number): number => a + b;
Highlights explicit return type addition `: number` in green
Key Features & Performance
- ✓Side-by-Side (Split) and Unified (Inline) code diff comparison.
- ✓Syntax highlighting across JavaScript, Python, Rust, Go, CSS, and HTML.
- ✓Word-level and character-level change highlighting.
- ✓100% Client-Side memory execution guarantees code confidentiality.
- ✓1-Click Copy patch diff.
Key Terminology & Definitions
Patch / Diff
A text file representing the delta differences between two versions of source code using standard unified format notation.
Hunk
A contiguous block of modified code lines within a diff file marked by line range headers (e.g. `@@ -1,5 +1,6 @@`).