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Analyze cyclomatic complexity and code metrics. Use when reviewing quality; for formatting use js-minifier. Input: code ≤10MB. Returns complexity scores. 100% client-side.
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Analyzes JavaScript and TypeScript code in the browser to estimate cyclomatic complexity, lines of code (total, code, comment, and blank), and a simple maintainability indicator. Highlights which functions are the most complex so you know where to refactor.
Complex code is harder to test and maintain, and it correlates with bugs, but it's hard to judge by eye. A quick complexity metric lets developers flag the riskiest functions and protect code quality before complexity becomes unmanageable.
This tool is part of the DevStackIO platform — a collection of free online developer tools from DevStackIO. Browse more free developer resources on DevStackIO.
Developers and tech leads performing code reviews, maintainers measuring technical and cognitive debt, and engineers deciding where to split or refactor functions.
Paste your JavaScript or TypeScript code into the editor
The analyzer reads LOC counts and complexity automatically
Review the overall score for the snippet
Read the function-level breakdown to find the highest-complexity functions
Use the recommendations to plan your refactoring
Run it again after refactoring to confirm complexity dropped
A function with 5 if/else branches and 2 loops → cyclomatic complexity ~8A 20-line pure function with no branches → cyclomatic complexity 1A module with many >10-complexity functions → the module is likely hard to maintainLOC breakdown: 120 total, 95 code, 12 comments, 13 blankWhat is cyclomatic complexity?
A count of independent paths through a function, based on decision points like if, else, case, and loop.
What is a good complexity score?
Value 10 per function is a common guideline; lower is easier to test and maintain.
Can it analyze TypeScript?
Yes, it understands TypeScript syntax as well as JavaScript.
Is my code sent anywhere?
No, all analysis runs locally in your browser.
Authoritative specifications, standards, and in-depth reading for Code Complexity Analyzer.
Total lines
12
Code
10
Comments
1
Blank
1
Overall
Cyclomatic complexity ~5
1 function · avg 5.0 per function · Moderate (68/100)
Highest complexity functions
Complexity counts decision points (if, for, while, catch, conditionals). It is a guide, not a judgement. All analysis happens locally in your browser.
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