nfd2nfc

[!NOTE] nfd2nfc is now on homebrew-core! If you previously installed via the tap, see Migration.

A macOS tool that watches directories and converts NFD filenames to NFC in real time, ensuring cross-platform compatibility.

What is NFD/NFC?

Unicode has two main ways to represent composed characters such as Korean Hangul, accented Latin (é, ü, ñ), Japanese kana (が, ぱ), and more:

NFC (Composed): One codepoint per character — 가 = U+AC00
NFD (Decomposed): Base + combining marks — 가 = U+1100 U+1161

macOS stores filenames in NFD, while Windows and Linux use NFC. This mismatch causes problems when sharing files across platforms:

Hangul syllables appear as decomposed jamo (e.g., 한글 → ㅎㅏㄴㄱㅡㄹ)
Accented characters may render or sort incorrectly
Git sees identical files as untracked or modified
Cloud sync and archive tools fail to match paths

nfd2nfc provides an interactive TUI, a scriptable CLI, and a background watcher service that handles conversion automatically.

Features

Real-time monitoring — Converts NFD filenames to NFC as soon as they appear
Flexible watch paths — Mix watch/ignore actions with recursive/children modes to control exactly which directories are monitored
Manual conversion — Convert filenames between NFD and NFC, individually or recursively
Log viewer — Review past watcher logs or follow new entries live
Intuitive TUI — Every keybinding is shown on screen, with full mouse support
CLI mode — Script and AI-agent friendly, with --json output and --dry-run previews

Home

The Home tab displays the current watcher service status and provides controls to start, stop, or restart it.

Config

The Config tab manages which directories the watcher monitors. Each path entry has an action (watch or ignore), mode (recursive or children), and validation status.

Logs

The Logs tab lets you browse past watcher logs and follow new entries in real time. Logs are stored in macOS system logs, and retention is managed by the OS.

Browser

The Browser tab lets you inspect files and directories for their Unicode normalization form and convert them directly. The watcher only picks up newly created or modified files, so use this tab to convert any existing NFD names.

CLI Mode

Running nfd2nfc without arguments launches the TUI. Add a command to use CLI mode. Run nfd2nfc <command> --help for detailed options.

nfd2nfc status [--json]
nfd2nfc watcher start|stop|restart
nfd2nfc config list [--json]
nfd2nfc config add <path> [--action watch|ignore] [--mode recursive|children] [--dry-run] [--json]
nfd2nfc config remove <index> [--dry-run] [--json]
nfd2nfc config sort
nfd2nfc convert <path> [--mode name|children|recursive] [--target nfc|nfd] [--dry-run] [--json]
nfd2nfc log show [--last 30m] [--json]
nfd2nfc log stream [--json]

Example:

$ nfd2nfc status
Watcher:          running
Version:          2.1.0
Binary:           /opt/homebrew/Cellar/nfd2nfc/2.1.0/bin/nfd2nfc
Watcher binary:   /opt/homebrew/Cellar/nfd2nfc/2.1.0/bin/nfd2nfc-watcher
Config:           ~/.config/nfd2nfc/config.toml
Plist:            ~/Library/LaunchAgents/io.github.elgar328.nfd2nfc.plist
Registered paths: 6 total (4 active, 1 overridden, 1 not found)
Full Disk Access: granted
Update:           up to date

Limitations

nfd2nfc solves the root cause of filenames breaking across operating systems — macOS storing them in NFD. However, other software (browsers, email services, cloud storage, messaging apps, archive tools, etc.) may independently convert filenames to NFD when transferring files. This is application-level behavior outside the scope of nfd2nfc.

Installation

Requires Homebrew.

brew install nfd2nfc

Then run it:

nfd2nfc

On first launch, the watcher service is automatically registered as a LaunchAgent. After that, you can start and stop it from the TUI or CLI.

Permissions

If macOS repeatedly prompts for folder access when the watcher converts files, grant Full Disk Access to the watcher binary:

Run which nfd2nfc-watcher to find the binary path
Open System Settings → Privacy & Security → Full Disk Access
If nfd2nfc-watcher is already listed, remove it completely (click -, not just toggle off)
Click +, press Cmd+Shift+G, paste the path from step 1, and add it
Run nfd2nfc status and verify that Full Disk Access shows granted

After upgrading to a new version, you must re-do the steps above to grant Full Disk Access again.

Note: On macOS Tahoe 26.1–26.2, Full Disk Access does not take effect for command-line binaries due to a system bug. This is resolved in macOS 26.3.

Migration

Starting with v2.0.7, nfd2nfc moved from the personal tap to homebrew-core. If you are using v2.0.6 or earlier, migrate with:

brew uninstall nfd2nfc
brew untap elgar328/nfd2nfc
brew install nfd2nfc

Upgrading

brew upgrade nfd2nfc

If you have granted Full Disk Access, you must reconfigure it after upgrading.

Uninstallation

brew uninstall nfd2nfc

License

MIT

Nfd2nfc

Install / Use

README