2,351 stars · MIT · v0.9 on GitHub, 0.9.0 on crates.io (2026-01-23) · Track this in Scout
Finds the rebuildable dependency and build folders that old projects leave behind across twenty-odd ecosystems, and shows the list before deleting anything.
▶Repo detailsthe review · specs · pros & cons · install
What it is
kondo is a small command-line program, with an optional window, that recognises more than twenty kinds of project — Rust, Java with Maven or Gradle, JavaScript, Python, .NET, Swift, Unity, Unreal Engine, Godot, Terraform and others — and knows which folder in each is safe to throw away.
What it is good for. Anyone whose disk filled up and who does not know where it went. A general disk-usage tool will tell you that fifty gigabytes sits in a hundred different node_modules folders; it will not tell you that all hundred are safe to delete. That is the difference here: it understands what kind of project it is looking at, so the list it shows you is a list of things you can lose without consequence. The payoff is usually tens of gigabytes on a machine that has been used for a few years.
- It knows more than one ecosystem. The single-language tools in this field each handle one; this handles over twenty, which is what makes it useful on a machine with a mixed pile of old work.
- It reports before it acts. There is a dry-run mode and a single-key mode, added in the current release, so the normal way to use it is to look at the list first.
- A plain MIT licence read from
/blob/master/LICENSE, unmodified, "Copyright (c) 2020 Trent Billington", and packages in Homebrew, winget, Arch Linux's pacman and MacPorts so there is no need to build it.
- It deletes, and there is no undo. The files are rebuildable, which is the point, but rebuilding means downloading everything again. On a slow connection, or for a project you need to work on this afternoon, that is a real cost. Run it with a dry run first, every time.
- The project is quiet. Release v0.9 is dated 23 January 2026 — the yearless GitHub date was confirmed against the Rust package index, which timestamps 0.9.0 at 2026-01-23 — and the newest code landed on 24 April 2026, about five months before this edition. That is well inside the eighteen-month line and it is not being called dead, but nothing has shipped since the spring. 32 open issues against 10 pull requests.
- Because it works from a list of known project types, a language it has not been taught is simply invisible to it. It will quietly skip what it does not recognise rather than warn you.
- voidcosmos/npkill
Does the same job for JavaScript alone, listing every node_modules folder with its size, which is tidier for a machine that only holds JavaScript work and useless for anything else.
Track this in Scout - holmgr/cargo-sweep
The Rust-only equivalent, and more precise there because it can delete only build output older than a given date, but its own page states that the project is currently unmaintained and looking for a maintainer.
Track this in Scout 
Byron/dua-cliEdition 36 covered this: it shows what filled a disk and can delete anything at all, which is more powerful and much less safe, because it has no idea which folders are rebuildable.
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brew install kondo # macOS or Linux with Homebrew winget install kondo # Windows sudo pacman -S kondo # Arch Linux # then, from the folder that holds your projects kondo --dry-run ~/code kondo ~/code # shows each folder and its size, and asks
