Code quality

What are complexity metrics?

Measuring how convoluted code is, typically cyclomatic or cognitive complexity per function.

By Cláudia FernandesUpdated 2026-10-02

Cyclomatic complexity counts independent paths through a function; cognitive complexity weights that by how hard the structure is for a human to follow. Both are proxies for how likely code is to hide a defect and how painful it will be to test.

Complexity is most useful as a trend and as a gate ('no new function above this threshold') rather than as a score to chase. Absolute numbers vary too much between languages and problem domains to compare across teams.

What to look for

Which metric is used, and whether the threshold is configurable
Function-level reporting rather than only file or repository averages
Whether complexity can fail a build or only appear on a dashboard
Trend tracking over time, which is more useful than a snapshot

Best 9 code quality, security and code review tools with complexity metrics

Every tool in the directory whose documentation covers this, 6 fully and 3 partially. Full support is shown first. Shown in a random order that changes on every visit, so no tool gets an advantage from its position.

Support is not the same as parity, since some implementations are narrower in scope, gated to a higher plan tier, or maintained only for existing customers. The note under each tool is what its own documentation describes.

Code Quality Platform

Cyclomatic complexity via Lizard and detekt; feeds the repository A-F grade.

PR Review Tool

Cyclomatic complexity analysis with complex-function identification and refactoring suggestions

Code Quality Platform

Code Health combines 25+ factors including nesting depth; cyclomatic complexity weighted low for poor predictive value

Code Quality Platform

Configurable cyclomatic complexity thresholds (low to critical) plus a Complexity Report Card dimension.

Code Quality Platform

First-party cognitive complexity engine plus cyclomatic complexity at file, directory and project level

Code Quality Platform

Complexity metrics reported alongside issue density and distribution measures.

Code Security Platform

AI rules flag long functions and deep nesting; no computed complexity metric.

Code Security Platform

Flags deeply-nested logic/complex one-liners qualitatively; no tracked complexity number

PR Review Tool

Custom rules can cap function length and complexity; no computed complexity metrics reported

Code Smell Detection Duplication Detection Dead Code Detection Test Coverage Tracking Diff Coverage (New Code)Architecture Governance

FAQ

What are complexity metrics?

Measuring how convoluted code is, typically cyclomatic or cognitive complexity per function.

How many tools in the directory offer complexity metrics?

9 of the 20 tools in this directory offer complexity metrics, 6 fully and 3 partially:

Aikido Codacy CodeAnt AI CodeScene Corgea DeepSource Greptile Qlty SonarQube

Support is not the same as parity, since some implementations are narrower in scope, gated to a higher plan tier, or maintained only for existing customers. The note under each tool is what its own documentation describes.

What should you check when comparing tools with complexity metrics?

Four things:

Which metric is used, and whether the threshold is configurable
Function-level reporting rather than only file or repository averages
Whether complexity can fail a build or only appear on a dashboard
Trend tracking over time, which is more useful than a snapshot