Developer Tools
Code Complexity Calculator
Code Complexity: code Complexity Calculator estimates cyclomatic complexity by counting the decision points (branches, loops and logical operators) plus one. Worked through below with real figures, and the calculator repeats the working on your own inputs — free, on-device, instant.
Code Complexity Calculator turns your source code into a complexity score using cyclomatic-complexity counting. The maths runs locally, so nothing you enter leaves the page.
Browser-side developer and utility helpers for everyday and learning use. Everything runs locally in your browser and nothing you enter is uploaded. Validate production or security-critical output with trusted, official tools before relying on it.
About this tool
It matters when a format, encoding or size has to be exactly right for the system reading it. The governing relationship: Code Complexity Calculator estimates cyclomatic complexity by counting the decision points (branches, loops and logical operators) plus one. See it on real numbers: Cyclomatic complexity = decision points + 1. A function with 3 if/loop branches scores 3 + 1 = 4 — lower is easier to test. The calculator above applies the same steps to whatever you enter — computed locally, nothing sent anywhere.
How to use
- Paste a function or code snippet into the box.
- Let the tool scan for decision keywords.
- Run it to count the branching points.
- Read the approximate cyclomatic complexity score.
Why use the Code Complexity Calculator
Instant
Each result is computed on your device the moment you run the tool.
Private
The text and numbers you enter stay in your browser and are never uploaded.
Free
No signup and no paywall to use any tool in this set.
Works offline
Once the page has loaded it keeps working on a weak or dropped connection.
Built for developers
Plain inputs and outputs you can copy straight into code, configs, or notes.
Honest by design
Conversions and heuristics are for everyday and learning use; verify security-critical output with trusted, official tools.
Common uses
Code Complexity in onboarding to a codebase
Code Complexity in code-review preparation
Use it for prioritising tech-debt work
Use it for quick complexity reference
Code Complexity in static-analysis workflows
Use it before merging a large change
Technical notes
Code Complexity Calculator estimates cyclomatic complexity by counting the decision points (branches, loops and logical operators) plus one.
Results are reference values; validate against your own environment before relying on them in production.
Nothing you type is uploaded — the calculation happens entirely on your device.
Worked example
Cyclomatic complexity = decision points + 1. A function with 3 if/loop branches scores 3 + 1 = 4 — lower is easier to test.
FAQ
How is the score calculated?
It counts decision points such as if, for, while, case, catch, and the and, or, and ternary operators, then adds one for the base path.
Is this an exact complexity measurement?
No. It is a keyword-based heuristic and can miscount in unusual code, so treat it as a rough guide rather than a precise metric.
Which languages does it work with?
It works best with C-style languages that use these keywords and operators, including JavaScript, Java, C, and similar.
Does pasted code leave my browser?
No. The snippet is analysed locally in your browser and is never uploaded or stored.