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complexity

Free#16 of 18 in Code Complexity Analyzers

complexity: A lightweight macOS utility for file-level complexity estimates and filterable output. Ranked #16 of 18 in Code Complexity Analyzers by our editors (5.8/10); pricing: Free plan; best for mac users needing a lightweight complexity estimate.

5.8/10Editor score
Visit thoughtbot
complexity5.8 Visit thoughtbot

At a glance

  • Editor score
    5.8 / 10
  • Pricing
    Free plan
  • Best for
    Mac users needing a lightweight complexity estimate
  • Free plan
    Yes
  • Paid from
    None
  • Hotspot detection
    Yes
  • Facts checked
    27 Sep 2026

  • Where it wins

    • Estimates complexity per file with indentation-based heuristics
    • Filters and excludes files by extension or path; honors .gitignore
    • Exports results as JSON or CSV and supports YAML configuration

  • Where it doesn't

    • Indentation-based estimates are not cyclomatic complexity
    • Listed for macOS, with distribution through a Homebrew tap
    • No IDE feedback, pull request gates, or trend history

Our verdict on complexity

For developers who want a local, file-level signal about code that may be difficult to understand, complexity is an open-source command-line utility from thoughtbot. It applies indentation-based heuristics rather than cyclomatic complexity, so it is best treated as a way to identify files for closer review, not as a comprehensive measure of code quality. The README describes use across codebases containing Ruby, Elixir, Python, Scala, TypeScript and JavaScript, Go, Elm, Swift, and Java. The product is distributed through thoughtbot’s Homebrew tap for macOS.

Its practical strengths are in narrowing and shaping the analysis. You can filter files by extension or path substring, exclude paths, and have the tool honor .gitignore settings. A configurable YAML file lets you specify ignored extensions and path substrings. Results can be emitted as text, JSON, or CSV, giving developers options for reading output directly or passing structured results to other tools. This makes complexity a focused fit for solo developers and small teams who want a lightweight local estimate without adding an IDE workflow or hosted service.

The trade-off is its narrow scope: its estimates depend on indentation, and it does not provide IDE feedback, pull request gates, or trend history. Teams that need those capabilities, or a more formal complexity method, should consider a broader analyzer instead. Choose complexity if a simple, filterable file-level signal and exportable output suit your workflow; look elsewhere if you need continuous tracking or automated review controls.

complexity pricing

Plans Free planFree Free to use — no paid tier required for the core job.
See plans on github.com

complexity fact sheet

Free planYes
Paid fromNone
Complexity metricsNot verified
Supported languagesNot verified
Hotspot detectionYes
IDE feedbackNo
Pull-request gatesNo
Trend historyNo
DeploymentDesktop
PlatformsmacOS
Built forSolo, Small business (editorial estimate)
PricingFree plan
Websitegithub.com
Facts checked27 Sep 2026

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Featured on iTechGuides

Featured on iTechGuides — complexity 5.8/10

complexity is listed in our Code Complexity Analyzers directory. Add the badge to your site — it links back to this page.

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Reviewed by iTechGuides Editors · Editorial team · Updated Sep 2026

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