Browser tool Runs locally
JavaScript Diff / Compare
Compare two JavaScript snippets and see structural changes without formatting noise. Runs locally in your browser.
Version A · Original / before
0 chars⌘/Ctrl + Enter to compare
Version B · Updated / after
0 chars⌘/Ctrl + Enter to compare
Examples:
Comparison result
Click Compare JavaScript to see structural differences.
How to compare JavaScript
- Paste the original source in Version A.
- Paste the updated source in Version B.
- Click Compare JavaScript.
- Review the structural differences.
What this JavaScript diff compares
- Identifiers, literals, operators.
- Statements, functions, classes.
- Modules and their sources.
- Structural order.
What formatting differences are ignored
- Indentation and line breaks.
- Whitespace around operators and punctuation.
- Comments (not part of the AST).
- Equivalent literal representations.
- Redundant parentheses.
Example
Given a change to an operator inside a function, the result reports exactly that.
Structural diff vs. text diff
A text diff compares line by line and reports every character. A structural diff parses both sources and reports only what changed in the program's structure.
Frequently asked questions
- What does this JavaScript diff tool compare?
- It parses both versions and compares their abstract syntax trees. Formatting and whitespace are not part of the AST.
- Does it execute my JavaScript?
- No. The parser reads both sources as text; nothing is evaluated.
- Is my code uploaded?
- No. Parsing, comparison, and rendering all happen in your browser.
- Does formatting affect the comparison?
- No. Indentation, line breaks, and whitespace are not in the AST.
- Are comments compared?
- No. Comments are not part of the executable AST that this tool compares.
- Does it support JSX or TypeScript?
- No. Non-standard syntax is detected and reported clearly.