Ballast

What it is

Ballast is a native SwiftUI app for macOS 26 that answers three questions in order: where did the space go, what can go safely, and will anything break? It is aimed at everyone who runs out of disk, and especially at developers, whose disks fill with node_modules, build output, toolchains, simulators and package-manager caches — things that are safe to throw away but hard to find.

How it sees the disk

Ballast walks /System/Volumes/Data once (not /, so firmlinked folders like /Users count once) and stores every folder in a SQLite index, with sizes taken from what is actually allocated on disk — what du reports — and hard links counted once. Every later launch replays the FSEvents log macOS already keeps and rechecks only the folders that changed. If that log can't be trusted — events dropped, IDs wrapped, the root changed — it falls back to a full scan instead of guessing.

External drives and other volumes get their own index, scanned only when you ask. APFS and Mac OS Extended drives are updated from their own change log; ExFAT and FAT start a new log on every mount, so Ballast rescans them and says so.

Never breaks anything

Every item gets one of four verdicts, checked again at the moment it is deleted:

Verdict	Examples
Safe	App caches, node_modules, DerivedData, downloaded installers
Quit the app first	A browser's cache while the browser is open
Check first	Git repositories, tool folders, apps
Protected	App data, Keychains, Mail, Photos, .ssh, .git

The default is Move to Trash, and every cleanup is logged so Put Back can restore it — never over something new that has appeared at the same path. Tools with their own cleanup command (npm cache clean, go clean -modcache, brew cleanup) run that command instead of deleting files. Ballast never asks for admin rights to delete.

Features

• Suggestions: tool caches (npm, Bun, pnpm, pip, Cargo, Go, Gradle, uv …), Xcode DerivedData and device support, logs, Trash, and folders untouched for six months or a period you choose.
• Build folders by type, each confirmed by the file that proves it — target/ only next to a Cargo.toml, .next only next to a package.json or Next config — never by name alone.
• Unused apps with what uninstalling frees, finding the app's data by exact identity only.
• What grew: the deepest folders that explain growth since last time, or over 24 hours, 7 or 30 days, without counting a byte twice.
• Largest files, duplicate files (APFS clones recognised as already sharing storage), and a breakdown of macOS's "System Data".
• Homebrew and Git worktree management through brew and git.
• Auto-clean rules, a menu bar item, a desktop widget, Shortcuts/Siri actions, and a low-space alert.
• A command line in the same binary for cron jobs or CI boxes.

Privacy

The index, growth history and cleanup log stay in ~/Library/Application Support/Ballast. Update checks (Sparkle) and anonymous usage data are both off until you allow them; usage events carry only values from fixed lists, booleans and ranges — never paths, names or exact sizes.

Install

Releases are on GitHub as Ballast.zip. Builds are signed ad-hoc and not notarized, so macOS asks you to approve the first launch. Full Disk Access is recommended so privacy-protected folders can be measured.

Stack

Swift 6, SwiftUI, SQLite, FSEvents, WidgetKit, App Intents, Sparkle. Licensed under the GNU AGPL v3.