A code snippet diff compares two code snippets with character-level precision and syntax highlighting. Unlike plain text diff tools, it highlights exactly which characters within a line changed — not just the whole line — and colors keywords, strings, and comments for the selected programming language.
How to Use the Code Snippet Diff
The code snippet diff goes beyond plain text comparison by adding two capabilities critical for code review: character-level precision (highlighting exactly which characters changed within a line) and syntax highlighting for 17 languages. Use it to review function changes, audit configuration edits, or spot subtle variable name typos.
Step 1: Select Your Language
Choose the programming language from the dropdown. This enables syntax highlighting — keywords, strings, comments, and numbers are colored appropriately for the selected language. Supported languages include JavaScript, TypeScript, Python, HTML, CSS, SQL, JSON, YAML, Java, Go, Rust, C/C++, PHP, Ruby, Shell/Bash, and XML.
Step 2: Paste Your Code
Paste the original (before) version in the left textarea and the modified (after) version in the right textarea. Click "Compare Code" — the diff updates automatically as you type, with a 500ms debounce to avoid lag on large snippets.
Reading the Character-Level Diff
Unchanged lines appear without highlighting. Added lines have a green left border. Removed lines have a red left border. Within changed lines, the specific characters that were added are shown with a green background inline, and removed characters are shown with a red background and strikethrough — giving you surgical precision on what exactly changed.
View Modes
Side-by-side shows original and modified code in parallel columns — best for reviewing substantial changes. Unified view shows a single column with + and - line prefixes, matching the output of git diff. Inline view shows the before and after version of each changed line consecutively, making it easy to read changes in context.
Toggling Features
The "Char-level diff" toggle enables or disables character-level highlighting within lines. Turn it off for large snippets if you only need line-level changes. The "Syntax highlight" toggle adds or removes language syntax coloring — disable it for languages not in the list or when you need a clean monochrome view.
FAQ
Is the code diff tool free?
Yes, completely free with no account required. All comparison and syntax highlighting runs locally in your browser — your code is never sent to any server.
How is this different from the plain text diff checker?
The code snippet diff adds two things the plain diff checker lacks: character-level precision (it highlights exactly which characters within a line changed, not just the whole line) and syntax highlighting (keywords, strings, comments, and numbers are colored for the selected language). For code review and debugging, this makes changes far easier to spot.
What languages are supported?
17 languages: JavaScript, TypeScript, Python, HTML, CSS, SQL, JSON, XML, YAML, Java, Go, Rust, C/C++, PHP, Ruby, Shell/Bash, and Plain Text. Syntax highlighting covers keywords, strings, comments, and numbers for each language.
What is character-level diff?
Standard diff tools highlight entire changed lines. Character-level diff goes further: within a changed line, it highlights exactly which characters were added (green background) or removed (red background with strikethrough). This is especially useful for spotting one-character typos or small variable name changes.
What view modes are available?
Three views: Side-by-side shows original and modified in parallel columns. Unified shows a single column with + and - prefixes, similar to git diff. Inline shows both old and new versions of each changed line together in one column, letting you see before and after in context.
Can I diff SQL queries, YAML configs, or shell scripts?
Yes. SQL, YAML, and Shell/Bash are all supported with syntax highlighting. For SQL, keywords like SELECT, WHERE, and JOIN are highlighted. For YAML, keys and values are styled. For shell scripts, builtins like echo, if, and for are recognized.