# include-what-you-use/include-what-you-use

A tool for use with clang to analyze #includes in C and C++ source files

Repository: https://github.com/include-what-you-use/include-what-you-use
Canonical: https://ross.abutalabs.com/products/include-what-you-use
Homepage: https://include-what-you-use.org
Language: C++
License: NOASSERTION
License Family: other
Last push: 2026-08-26T19:56:42+00:00

## Health v2 (maintenance only)
Score: 82/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 99, release rhythm 51, longevity 100
- inputs: {"age_days": 4097, "days_push": 7, "days_rel": 164, "gap_med": 167, "n_releases_24m": 4}
- flags: no_license
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 4757, forks 432 (observed 2026-08-28T04:08:58.931611+00:00)

## What it is
Include What You Use (IWYU) is a Clang-based tool that analyzes #include directives in C and C++ source files. It detects superfluous includes, suggests missing ones, and recommends replacing includes with forward declarations where possible.

## Use cases
- remove unused #includes from C++ files
- find missing headers for symbols used in source files
- replace includes with forward declarations
- automatically track and clean up header dependencies
- enforce include hygiene in a large C++ codebase

## When to choose
- you maintain a large C or C++ codebase with messy or stale includes
- you want to reduce compile times by eliminating unnecessary headers
- you want automated suggestions for correct includes per symbol usage

## When to avoid
- your project does not use C or C++
- you need a tool decoupled from specific Clang versions, since IWYU breaks with Clang updates
- you need fully stable production-grade behavior, as the project describes itself as experimental

## Facets
- artifact type: cli-tool
- maturity: active
- function: linter, developer-tools, parser
- domain: developer-tools, programming-languages, parsers
- platform: windows, cpp, cli
- tags: clang, static-analysis, c-plus-plus, includes, code-quality, linux, macos

## Member repositories
- include-what-you-use/include-what-you-use (main) score 82

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:08:58.931611+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-29T18:18:52.599694+00:00, confidence not recorded.
  - readme: https://github.com/include-what-you-use/include-what-you-use (fetched 2026-08-28T04:08:58.931611+00:00, sha 0a9c97f1c2e1)
  - homepage: https://include-what-you-use.org (fetched 2026-08-29T09:02:16.636106+00:00, sha 1e949b19b582)
- Data as of 2026-08-30T08:39:29.467469+00:00.