Fixing grammar and rewriting text on a Mac, without uploading the draft
Grammarly Pro costs $30 a month, or $144 a year, and checks your text on Grammarly's servers. macOS spelling and grammar is free. Apple Writing Tools are free on an Apple silicon Mac, though proofreading may go to Apple's servers. Vocemo rewrites text on your Mac for $15 a month.
- Grammarly Pro
- $30 a month, $60 a quarter, or $144 a year
- ProWritingAid Premium
- 30 a month, 120 a year, or 399 once for a lifetime licence
- Free on every Mac
- Spelling and grammar checks, plus Writing Tools on Apple silicon
- The local option
- A rewrite palette on your own Mac, $15 a month
Does Grammarly read everything you type?
Grammarly answers this on its own support pages, and the answer is more precise than either side of the usual argument. Its product "can't access anything you type unless you are actively using a Grammarly product offering, such as the browser extension". But when it is active, the position is plain: "While you're using Grammarly, it needs access to your text in order to provide suggestions."
That access is not local. Grammarly's privacy pages say it hosts data in Amazon Web Services data centres in the US East region. Its article on why the iPhone keyboard needs full access is blunter still: the keyboard needs an internet connection "because we use powerful servers to check your text and provide suggestions". The checking happens on a server, so the text has to get there.
On a Mac the interesting part is how wide "actively using" turns out to be. The desktop app is designed to sit inside text fields in other apps, and the browser extension covers most of what you type in a browser. Grammarly says credit card numbers and passwords are excluded on a best effort basis, and that you can turn a feature off or switch the product off for a particular piece of text. So the honest description is not "it reads everything", it is "it reads what you write wherever you left it switched on, which for most people is nearly everywhere".
What does that mean for a confidential draft?
For a shopping list, nothing. The cases that matter are ordinary work.
- A solicitor drafting a letter about a live matter.
- An HR note about a named employee.
- A clinician writing a referral with a patient's history in it.
- A product announcement with a launch date that is not public yet.
- A board email written the week before results.
- Anything covered by a non disclosure agreement you signed.
None of those are secret in a dramatic sense. They are simply documents that a contract, a regulator or a professional duty says you will not hand to a third party. A grammar checker that sends the text to a server is a third party, however careful that server is. Many employers already answer this with a policy, and it is worth checking yours before installing anything that types alongside you. The general shape of this trade is covered in running AI on your own Mac.
Does macOS have a built in grammar checker?
Yes, and people forget it because it is quiet. Spelling and grammar checking is part of the text system, so it works in TextEdit, Mail, Notes, Pages and most apps that use standard text fields. In TextEdit you turn the options on under TextEdit, Settings, New Document. System wide, the settings live under System Settings, Keyboard, Text Input, Edit.
It catches misspellings, doubled words, some agreement errors and obvious punctuation slips. It runs on your Mac and it costs nothing. What it does not do is rewrite. It will not shorten a paragraph, change a tone or turn a rambling dictated sentence into a clean one.
Are Apple Writing Tools on device?
Partly, and Apple says which part. Writing Tools can proofread text, rewrite it to be more professional, friendly or concise, and summarise long passages. They are free, and they need Apple Intelligence turned on, which means a Mac with Apple silicon, macOS Sequoia 15.1 or later and about 7 GB of storage for the models.
Apple's privacy page for Apple Intelligence says models run entirely on device "when possible", then gives the exception using this exact feature: "when you use Writing Tools to proofread or edit an email, your device may send the email to Private Cloud Compute for a server based model to do the proofreading or editing". Apple states that data sent to Private Cloud Compute is not stored or made accessible to Apple, and is processed only to fulfil the request.
That is a much better bargain than a standard cloud service, and it is still not the same as nothing leaving the machine. If you need to know what left, macOS keeps a record: System Settings, Privacy and Security, Apple Intelligence Report. Turn it on, use the feature, then export the file and read it. Note also that the optional ChatGPT extension is a separate hop to a separate company, and only applies when you choose it.
What do the grammar and rewriting tools cost?
Prices checked September 2026, taken from each vendor's own pricing page.
| Tool | Where the text goes | Price |
|---|---|---|
| macOS spelling and grammar | Stays on your Mac | Free with macOS |
| Apple Writing Tools | On device, or Apple's Private Cloud Compute | Free, needs an Apple silicon Mac and macOS 15.1 or later |
| Grammarly Free | Grammarly's servers | $0, with 100 AI prompts a month and no sentence rewrites |
| Grammarly Pro | Grammarly's servers | $30 a month, $60 a quarter, or $144 a year, which is $12 a month |
| ProWritingAid Free | ProWritingAid's servers | Free, with 500 words a check, 2 report runs a day and 10 rephrases a day |
| ProWritingAid Premium | ProWritingAid's servers | 30 a month, 120 a year, or 399 once for a lifetime licence |
| ProWritingAid Premium Pro | ProWritingAid's servers | 36 a month, 144 a year, or 699 once for a lifetime licence |
| Vocemo | Stays on your Mac | $15 a month, or $144 a year, which is $12 a month |
If you would rather this ran on your own Mac, that is what Vocemo does. Free for 7 days, then $15 a month for 3 Macs.
Download free for MacTwo notes on those figures. Grammarly's support page states the default currency is the US dollar, with regional pricing in euros, pounds and rupees. The ProWritingAid page bills in local currency and showed euros when it was checked, so the figures above are 30, 120 and 399 in the currency your checkout offers. Check the number at the payment step rather than trusting a comparison table, this one included.
The annual figures are worth reading twice. Grammarly Pro at $144 a year and Vocemo at $144 a year are the same money. One does the work on a server in Virginia, the other does it on the laptop in front of you.
What can a local rewrite actually do?
Vocemo runs a small language model on the Mac and puts it behind a rewrite palette. You give it text, usually text you have just dictated, and it comes back cleaned up: punctuation added, repetition dropped, the false starts of speech turned into sentences. Two other pieces do the boring work around it. Replacement rules fix the same recurring error every time, which is how you stop a product name, a drug name or a client's surname being mangled. Snippets expand a short trigger into a fixed block of text you type often.
Nothing about that needs a network. Models download the first time a feature needs one, then shut down after 120 seconds of sitting idle. The installer is 5.5 MB, because the weights are not in it. It costs $15 a month, or $144 a year, there is a 7 day trial with no account, and one licence covers 3 Macs.
For the common job, which is turning spoken sentences and hurried typing into clean prose, that is enough. A small model on Apple silicon is good at tidying and shortening, because those tasks depend more on structure than on world knowledge.
What does the local option not do?
Worth being blunt, because the gaps are real and none of them are secret.
- It does not underline errors as you type in every app. The palette is something you invoke on text. Grammarly's habit of appearing inside any text field is genuinely convenient, and that convenience is exactly the thing that makes it read your writing.
- No plagiarism checking and no AI detection. Both need a corpus the size of the web. Neither can run on a laptop.
- No writing reports. ProWritingAid's readability scores, overused word counts, sentence length graphs and author comparisons are its main attraction for novelists. There is no local version of that here.
- No team style guide or brand tones. Shared rules across an organisation are a server feature, because they are shared.
- No browser extension, Google Docs panel or Word add in.
- A small model has limits. On unusual syntax, technical prose or a language it handles poorly, a large server model will produce a better rewrite. That is a real quality difference, not a marketing one.
- Apple silicon only, macOS 13 or later. No Intel Macs, no Windows.
Which tool for which draft?
- A confidential letter, note or announcement. Keep it on the Mac. Built in spelling and grammar for the errors, a local rewrite for the tidying.
- A novel manuscript. ProWritingAid, and pay the lifetime price if you write every year. The reports are the product and nothing local replaces them.
- Everyday email and public marketing copy. Grammarly Free covers spelling and tone signals at no cost. Pro buys sentence rewrites.
- Dictated text that needs punctuating. A local rewrite palette, because the job is cleanup rather than judgement.
- Anything your employer's policy names. Read the policy first. Several sectors already forbid pasting client material into any external service.
Questions
Is there a grammar checker that works offline on a Mac?
Yes, in two forms. macOS has spelling and grammar checking built in to the text system, so it works in Mail, Notes, Pages and TextEdit at no cost. For rewriting rather than error marking, a local language model can clean up text on an Apple silicon Mac, which is what Vocemo's rewrite palette does for $15 a month.
Does Grammarly send my text to its servers?
Yes, when it is active in a text field. Grammarly's support pages say the product needs access to your text to provide suggestions, and that its iPhone keyboard needs an internet connection because the checking runs on Grammarly's servers. Its data is hosted in Amazon Web Services data centres in the US East region.
How much does Grammarly Pro cost?
Grammarly's support page lists $30 a month, $60 for three months, or $144 a year, which averages $12 a month per member. The free plan stays at $0 and includes 100 AI prompts a month, but not sentence rewrites or tone adjustment. Grammarly does not sell lifetime or one time plans.
How much does ProWritingAid cost?
Premium is 30 a month, 120 for a year, or 399 as a one time lifetime licence. Premium Pro is 36 a month, 144 a year, or 699 for life. The free plan allows 500 words a check, 2 runs of each report a day and 10 rephrases a day, and the site prices in your local currency.
Are Apple Writing Tools free and private?
They are free with Apple Intelligence on a Mac with Apple silicon running macOS Sequoia 15.1 or later. Apple says models run on device when possible, but that proofreading or editing an email may be sent to Private Cloud Compute for a server based model. You can see what left the Mac in System Settings, Privacy and Security, Apple Intelligence Report.
Can a local rewrite replace Grammarly?
For cleaning up dictation, tightening sentences and fixing recurring errors, yes. For plagiarism checks, AI detection, writing reports and a suggestion layer inside every text field, no. Those either need a large corpus or a service watching what you type, and neither of those runs on your own Mac.
Sources
Every price on this page was read from the vendor's own page on the date shown above. Prices change; if you find one out of date, tell us and we will correct it.
Competitor prices in this article were checked in September 2026. Prices change; if you find one out of date, write to us and we will correct it.