NEWBuilt-in offline AI — polish your dictation 100% on-device
May 30, 2026·4 min read

Built-in Offline AI Cleanup: Edit Prompts, Set Tones, Stay Private

offline AI transcriptionon-device speech to textprivate dictationedit AI promptvoice typing tones

Built-in Offline AI Cleanup

Whisper can now clean up your dictation as you speak — fix grammar, drop the "ums," and even reshape a blunt note into something polished. The part we're most proud of: it runs entirely on your own computer. No account, no API key, nothing sent to the cloud.

This guide covers everything: how to turn it on, the built-in tones, how to edit the prompt yourself, undo, and how numbers and times are handled.

It's off by default. Whisper works exactly as it always has until you choose to enable this. Nothing changes unless you want it to.

What it does

When enabled, every time you finish dictating, Whisper passes your transcript through a small AI model running locally and pastes the cleaned-up result instead of the raw text. Typical fixes:

  • Grammar, punctuation, and capitalization
  • Removing filler words (um, uh, like)
  • Reshaping tone (warmer, more formal, email-ready)
  • Reformatting into bullet points or code

Turning it on

  1. Open Settings → Post Processing
  2. Flip the master toggle on
  3. Choose a provider:
    • Built-in (offline) — runs on your computer, no setup beyond a one-time model download
    • Or connect your own API provider (OpenAI-compatible) if you prefer

For the built-in option, click Download model once (a ~390 MB file). After that it works fully offline, forever.

Tones (the preset prompts)

Tap a preset to instantly set the behavior:

Preset What it does
Improve Fix grammar, punctuation, remove fillers — keep your meaning and tone
Polite Rewrite to sound warm and professional
Formal Rewrite in a formal, professional tone
Email Format as a clear, well-structured email
Bullet points Convert into concise bullets
Code Format as code with proper indentation

Editing the prompt yourself

This is the real power of the feature: the prompt is just text you can edit. The presets above simply fill in the prompt box for you — you're free to change it to anything.

Want Whisper to always sign off with your name? Translate as it cleans up? Keep it terse? Just write the instruction in the prompt field under Settings → Post Processing. A few examples you can paste in:

  • Fix grammar and make it concise. Never use exclamation marks.
  • Rewrite in British English, formal tone. Only return the rewritten text.
  • Summarize into 3 short bullet points.
  • Translate to German, keeping a professional tone.

Tip: end your prompt with "Only return the rewritten text." so the AI doesn't add commentary.

If a preset is almost right but not perfect, start from it and tweak the wording — that's exactly what it's there for.

Undo: get your exact words back

Don't love the AI's version? Press the Undo AI cleanup shortcut (default ⌥Z on Mac, Ctrl+Shift+Z elsewhere) right after pasting, and Whisper replaces it with your original, word-for-word transcript. You can rebind the shortcut in Settings → Shortcuts.

How numbers and times are handled

Whisper digitizes numbers only when they're clearly a time, amount, or percentage — and leaves everything else as words:

  • "let's meet at two pm" → "let's meet at 2 PM"
  • "ten thirty" → "10:30"
  • "about fifty percent" → "50%"
  • "I have two ideas" → stays "two ideas"

This happens deterministically (not via the AI), so it's consistent. The AI cleanup is also instructed to leave your number formatting alone, so prose numbers stay spelled out even after a rewrite.

Custom vocabulary

Names, brands, and jargon that get mis-transcribed? Add them under Settings → Custom Words. You can add them one at a time or paste a whole list at once (comma- or line-separated) with Import list.

Privacy

With the built-in (offline) provider, your dictation never leaves your computer. There's no account, no API key, and no network request for the cleanup step. That's the whole point of Whisper — and the on-device AI keeps that promise.


Ready to try it? Make sure you're on the latest version from get-whisper.com/download, then head to Settings → Post Processing. And remember — it's off by default, and one toggle turns it back off if it's not for you.

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