Local AI Writing Tools for Mac: Keep Your Text On-Device (2026)

Every mainstream AI writing assistant has the same fine print: your text is sent to a server. For a casual email that may not matter. For a contract under NDA, a client deliverable, an unpublished manuscript, or an internal memo, it absolutely does. The good news is that in 2026 you no longer have to choose between AI help and confidentiality. A small but growing group of local AI writing tools for Mac run the model entirely on your own hardware — your words never touch the internet, they work on a plane, and there is no metered API bill quietly growing in the background.

This roundup covers the Mac apps where your text can genuinely stay on-device, what each one is good at, and — just as important — what small local models honestly can and cannot do. If you want the broader picture first, see our guide to the best AI writing apps for Mac.

Three flavors of “local” (and one that isn't)

Marketing pages use “private” and “local” loosely, so it helps to separate three very different architectures:

• Built-in on-device AI. The app ships with (or downloads) its own model and runs it inside the app — on Apple Silicon this usually means Apple's MLX framework. Zero setup, works offline out of the box. WunderType, Fluent, Typeahead, and Cotypist take this approach. Note this is different from Apple Intelligence, which is Apple's own system feature with its own limits — we compare the two in WunderType vs Apple Intelligence Writing Tools.
• Local runtime. The app connects to a model server you run yourself, typically Ollama or LM Studio. Still fully private — the “server” is localhost — but you install the runtime and pull models yourself. In exchange, you choose exactly which model to run. WunderType, MyRephra 2, Witsy, and Fluent all support this.
• BYO cloud key. The app has no backend of its own, but it sends your text to OpenAI, Anthropic, or OpenRouter using your API key. That is better than an opaque middleman server — no third party in between, and you control the account — but it is not local. Your text still leaves the Mac. Plenty of “privacy-focused” apps are actually in this category, so read the fine print.

Everything featured below can operate in one of the first two modes. Several apps offer cloud keys as an optional extra, which is fine — as long as local is a real, first-class option.

The local AI writing tools compared

App	Local approach	Setup required	Pricing	Works in any app?	Platform
WunderType	Built-in MLX on-device models + Ollama	None for on-device mode	$8.99 one-time	Yes — in-place text replacement	macOS 15+
Fluent	Local MLX in-app; also Ollama / LM Studio	Model download	From $49 one-time	Yes — floating Smart Panel	macOS
Typeahead	Fully local autocomplete model	~3 GB model download	$79 one-time	Yes — inline suggestions	macOS 14+, Intel or Apple Silicon
Cotypist	Local autocomplete model	Model download	Free tier; Plus $8/mo, Pro $12/mo	Most apps	macOS 14+, Apple Silicon only
MyRephra 2	Ollama (or LM Studio); optional OpenRouter	Install Ollama, pull a model	Free	Yes — fn-key trigger	macOS
Witsy	Ollama / LM Studio; many cloud options	Install Ollama for local use	Free, open source (AGPL-3.0)	Yes — Prompt Anywhere	macOS, Windows, Linux
Ollama	The local runtime itself	Install + pull models	Free, open source	N/A — powers other apps	macOS, Windows, Linux

WunderType — built-in on-device AI, zero setup

WunderType is, as far as we can tell, the only Mac writing tool that combines built-in Apple MLX on-device models with true inline, in-place text replacement. Select text in any app — Mail, Slack, Word, a browser — press a shortcut, and the corrected or rewritten text replaces your selection right where it sits, via the macOS Accessibility API. No panel, no copy-paste. The on-device mode requires no setup at all and works offline; if you want bigger local models, point it at Ollama, or optionally use your own OpenAI or OpenRouter key. It ships five built-in modes plus unlimited custom prompts with per-prompt shortcuts, collects zero analytics, requires no account, runs sandboxed with no backend server, and uses under 5 MB of memory. One-time purchase, $8.99 on the Mac App Store; requires macOS 15.

Fluent — local MLX in a system-wide panel

Fluent is a polished AI assistant built around a floating “Smart Panel” you can summon in any macOS app. It runs local MLX models in-app, and can also use Apple Intelligence or any OpenAI-compatible endpoint including Ollama and LM Studio — so a fully private setup is genuinely possible. Beyond rewriting and tone changes it does document chat and custom actions, making it more of a general assistant than a pure text fixer. Pricing is a one-time purchase starting at $49 for one Mac, with a 7-day trial. The trade-off versus in-place tools: your workflow runs through the panel rather than editing text where it lives. We compare it in depth in our Fluent alternative for Mac guide.

Typeahead — fully local autocomplete, pay once

Typeahead does one thing: inline autocomplete in every Mac app, powered entirely by a model on your machine. Its pitch is blunt and refreshing — “your words never leave your computer,” no servers, no accounts, no telemetry — and after the one-time license activation it runs offline. Suggestions appear as you type and you accept them with Tab; the model adapts to your writing style over a few days. It needs macOS 14+, 8 GB of RAM, and about 3 GB of disk for the model, and notably it still supports Intel Macs. At $79 one-time it is the priciest tool here, though with no subscription it can still win long-term. See our Typeahead alternatives comparison for how it stacks up.

Cotypist — local autocomplete with a free tier

Cotypist also does system-wide autocomplete with a fully local model — all processing happens on your Mac, so nothing you type ends up in anyone's training data. It works across most apps (Google Docs needs a small settings tweak), and completions are near-instant on an M-series machine. Unlike Typeahead it is Apple Silicon only and subscription-based: a free tier covers your first 100 completed words per day, with Plus at $8/month and Pro at $12/month for unlimited completions. Expect roughly 1–2.5 GB of memory use while active, with 16 GB RAM recommended. If autocomplete is your thing but the subscription isn't, our Cotypist alternatives roundup and Cotypist vs WunderType comparison cover the options.

MyRephra 2 — free rephrasing via Ollama

MyRephra 2 is a free, system-wide paraphrasing utility: select text anywhere, tap the fn key (or double-tap Shift), and it rewrites the selection through a local Ollama model — no intermediate servers, no logging, no subscription. You can build a library of custom prompts, and if you'd rather not download model files it can optionally use OpenRouter with your key instead (which, per the taxonomy above, is no longer local). The catch is the setup: you install and manage Ollama yourself, and the experience depends heavily on which model your Mac can comfortably run. As a zero-cost entry point into local AI writing, though, it's hard to argue with.

Witsy — the open-source Swiss Army knife

Witsy is a free, open-source (AGPL-3.0) desktop AI assistant for macOS, Windows, and Linux. Its “Prompt Anywhere” feature generates text into whatever app you're using via a shortcut, and “AI Commands” run transformations on selected text system-wide. It connects to just about everything, and crucially that includes Ollama and LM Studio, so a fully local configuration works. It even does speech-to-text with local Whisper. Being a cross-platform app, it feels less Mac-native than the others here, and the sheer number of options means more fiddling before it clicks. But for tinkerers who want maximum flexibility at zero cost, Witsy is the obvious pick.

Ollama — the runtime behind the apps

Ollama isn't a writing app, but it earns a spot because half this list plugs into it. It's a free, open-source runtime that downloads and serves open models — Llama, Gemma, Qwen, Mistral and friends — on localhost. Install it, pull a model with one command, and any compatible app (WunderType, MyRephra 2, Witsy, Fluent) can use that model privately. The advantage over built-in models is choice: on a 16 GB or 32 GB Apple Silicon Mac you can run notably larger, smarter models than most apps would bundle. The cost is disk space (2–20 GB per model), RAM while a model is loaded, and a little command-line comfort.

What local models can and can't do

Honesty time. The models that run comfortably on a consumer Mac are in the 1–12 billion parameter range — a fraction of the size of frontier cloud models. For the tasks most writing tools are built around, that's fine: grammar and spelling correction, tone adjustment, tightening a paragraph, rewriting a sentence, translating short passages are well within reach of a good small model, and on Apple Silicon they respond fast because there is no network round-trip.

Where small models fall short is nuanced long-form work: drafting a subtle 2,000-word essay, deep restructuring of a document, or reasoning-heavy edits where the model must hold a lot of context at once. They also hallucinate more readily when asked to generate facts. Practical hardware notes: Apple Silicon (M1 or later) is effectively required for a good experience — MLX is Apple Silicon-only, and Cotypist won't even install on Intel. 8 GB of RAM works for small models; 16 GB and up is where local AI gets comfortable. Budget a few gigabytes of disk per model.

The sensible pattern most local-first apps enable: do everyday corrections and rewrites on-device, and keep an optional cloud key for the rare heavy-duty task — used knowingly, not by default.

Verdict

If you want the shortest path to private, local AI writing on a Mac, WunderType is the standout: it's the only tool here with built-in MLX on-device models and in-place text replacement in any app, it needs zero setup, and at $8.99 one-time it costs less than a single month of most subscriptions — part of why it also features in our one-time purchase AI apps guide. Pick Typeahead or Cotypist if autocomplete-while-you-type is specifically what you want, Fluent if you prefer a do-everything panel, and MyRephra 2 or Witsy if free and tinker-friendly beats polished.

Your drafts, contracts, and half-formed ideas don't need to be uploaded to be improved. Download WunderType from the Mac App Store and keep your writing on your Mac, where it belongs.