cmakefmt

Why cmakefmt?

Up-to-date specs

Built-in specs for 150+ commands, audited against CMake 4.3. cmake-format hasn't been updated since 2021 and misses many modern commands and arguments.

Whole-project, instant

Recursive discovery and parallel formatting by default. Point it at your project root — no file lists, no wrapper scripts.

Zero dependencies

One binary. No Python, no virtualenv, no dependency drift. Drop it in CI and forget about it.

Editor-ready

Built-in LSP server, VS Code extension, format-on-save for Neovim, Helix, Zed, and Emacs — plus config autocomplete via SchemaStore.

Built for workflows

--check, --diff, --staged, --explain, Git-aware file selection, semantic verification, JSON reporting — all first-class.

One-command migration

Already using cmake-format? cmakefmt config convert translates your existing config — no manual rewriting.

See all features ↓

Quick Start

macOS

❯ brew install cmakefmt/cmakefmt/cmakefmt

Cargo

❯ cargo install cmakefmt-rust

pip

❯ pip install cmakefmt

Or download a pre-built binary from GitHub Releases.

Then — just point it at your project. It discovers all CMake files recursively and formats them in parallel:

cmakefmt config init               # generate a starter .cmakefmt.yaml
cmakefmt --check .                 # dry-run: just show which files would change
cmakefmt .                         # dry-run: preview formatted output; changed lines shown in blue
cmakefmt --diff .                  # dry-run: view a unified diff of what would change (like `git diff`)
cmakefmt --in-place .              # apply formatting across the whole project
cmakefmt --staged --check          # use in pre-commit hooks
cmakefmt --path-regex 'src/.*' .   # format CMake files only under src/

Before and After

Formatter Demo

Watch rough CMake settle into a stable layout.

The landing-page animation shows the kind of cleanup cmakefmt performs in one pass: casing becomes consistent, simple lists collapse, and larger calls wrap into a readable structure.

normalises casing collapses obvious lists wraps complex calls

messy input cmakefmt output

Play Replay

CMAKE_MINIMUM_REQUIRED(VERSION 3.20)
Project(myproject LANGUAGES CXX)

set(SOURCES src/main.cpp
src/utils.cpp
  src/parser.cpp)

target_link_libraries(mylib PUBLIC
Boost::filesystem Boost::system    fmt::fmt
  PRIVATE
    spdlog::spdlog)

IF(WIN32)
MESSAGE(STATUS "building on Windows")
ENDIF()

Performance

1× geometric-mean speedup over cmake-format across 11 real-world fixtures. On a 282-file repository: ~997× faster sequentially, ~2,853× faster with --parallel.

Linear Log

See Performance for the full methodology and benchmark environment.

Want to try it without installing? Open the Playground →

Where to Go Next

New to cmakefmt?

Getting Started Install and run your first format in under a minute.

Formatting Cookbook Common formatting goals with before/after examples.

Migrating from cmake-format?

Migration Guide Switch from cmake-format with one command.

CLI Reference Every flag, every output mode, every exit code.

Embedding cmakefmt as a library?

Library API format_source and friends, with full Rust code examples.

Architecture How the parser, registry, and formatter pipeline works.