Does ButterKeys work offline?

Yes. Correction works fully offline. Optional Sparkle update checks only contact the release feed and never include keystrokes or typing data.

What macOS permissions does ButterKeys need?

Input Monitoring and Accessibility, granted for the copy in /Applications. After enabling both, quit and relaunch ButterKeys from Applications.

How do I teach ButterKeys my own typos?

Select the mistake and press Control-Option-T (or use Teach in the menu bar) to save an explicit rule. You can also accept Learning suggestions so they become real rules.

How is ButterKeys different from system autocorrect or Grammarly?

System autocorrect and Grammarly focus on spelling and grammar, often with cloud features. ButterKeys is local-first and focused on the finger slips you repeat. When unsure, it leaves your text alone.

Typing,
but smoother.

Q: Is ButterKeys a cloud spellchecker?

No. ButterKeys runs entirely on your Mac. It targets recurring personal motor-pattern slips (like teh→the), not generic cloud grammar or AI rewriting. Corrections never leave the machine.

A macOS menu bar app that quietly melts your recurring finger slips into the words you meant, on your Mac, offline.

Download for Mac GitHub

macOS 14+ · Apple Silicon · Free · No account

Motor patterns, not spellcheck

ButterKeys watches for the mistakes you repeat, adjacent swaps, early spaces, the classic teh, and only acts when it's confident. Teach it the rest.

Melt, don't nag

High-confidence slips become the right word as you type. Unsure? It leaves your text alone.

Teach from selection

Select a typo and press ⌃⌥T (or menu → Teach) to save a personal rule. Learning suggestions become rules when you accept them.

Fridge-local

No cloud AI. No sentence storage. Just compact pairs like soem→some on your Mac.

Not another spellchecker

Same keyboard, different job. ButterKeys is for the slips your fingers keep making, not for rewriting your prose in the cloud.

ButterKeys

Motor-pattern typos you repeat
Runs fully on your Mac
Teach rules; stay quiet when unsure
Code editors stay in a narrower mode

Typical spellcheck / grammar apps

Spelling, grammar, and style suggestions
Often cloud-backed or account-based
Broad rewrites and underline nags
Not tuned for personal finger slips

FAQ

Straight answers for humans and answer engines.

Is ButterKeys a cloud spellchecker?

No. It runs on your Mac and targets recurring personal motor-pattern slips (like teh→the), not cloud grammar or AI rewriting. Corrections never leave the machine.

Does it work offline?

Yes. Correction is fully offline. Optional update checks only contact the release feed and never include typing data.

What permissions does it need?

Input Monitoring and Accessibility for the copy in /Applications. Enable both, then quit and relaunch from Applications. See the install guide.

How do I teach it my typos?

Select the mistake and press ⌃⌥T (or menu → Teach). Accept Learning suggestions to turn them into real rules.

How do I undo a correction?

Press ⌃⌥Z or use Undo in the menu bar. Host-app ⌘Z is not guaranteed to reverse a ButterKeys replacement.

macOS says the app can't be opened. What now?

Early builds may not be Developer ID–notarized yet. In System Settings → Privacy & Security, choose Open Anyway, or right-click the app → Open. Details in the install guide.

Spread some ButterKeys

Version 1.0.0 for macOS 14+. Free DMG from GitHub Releases. Open source.

After install: enable Input Monitoring + Accessibility for ButterKeys in Applications, then relaunch.
Also on GitHub Releases · Report a problem