Apple Intelligence shipped with iOS 18.1 and made a lot of headlines. Writing Tools showed up in the demo reels. Grammarly put out a blog post about it. Tech reviewers compared them.
Most of the coverage missed two things that actually matter: which iPhones can run Apple Intelligence at all, and what happens to your text with each tool.
Here is an honest breakdown.
Quick verdict
| Apple Intelligence | Grammarly | Proofed | |
|---|---|---|---|
| Price | Free (device requirement) | Free / $30 per month | Free / $4.99 per month |
| Works offline | Yes | No | Yes |
| Device requirement | iPhone 15 Pro+ or iPhone 16+ | Any iPhone (iOS 16+) | iPhone with iOS 17+ |
| Text leaves device | No | Yes | No |
| Account required | No | Yes | No |
| Grammar depth | Basic (Writing Tools) | Deep | Deep (on-device) |
Apple Intelligence: what it actually does for grammar
Apple Writing Tools shows up as a context menu when you highlight text in Notes, Mail, Messages, or any app that supports the standard text view. You get four options: Proofread, Rewrite, Make Shorter, Make Longer.
Proofread is the grammar checker. For basic grammar mistakes and spelling errors, it works fine. It will catch a missing word, a tense mismatch, obvious punctuation errors.
What it does not do: deep style analysis, passive voice suggestions, clarity scores, sentence structure feedback, tone detection. It is closer to a smart spellchecker than a full writing assistant.
The bigger issue: Apple Intelligence requires an iPhone 15 Pro (A17 Pro chip) or any iPhone 16. That is not most iPhones in use right now. Worldwide, the iPhone 13 and 14 are still in hundreds of millions of pockets. None of them can run Apple Intelligence. If you have an older device, Apple Writing Tools for grammar simply does not exist for you.
There is also the region issue. Apple Intelligence rolled out in English first. Other languages have been added gradually. If you write in a language Apple has not yet enabled, or you are in a market where the rollout is still pending, you may not have access regardless of your device.
Grammarly: what it does well and what it costs
Grammarly is a genuinely good product. It catches grammar mistakes that Apple Writing Tools misses. It analyzes sentence clarity, flags passive voice, identifies wordiness. The browser extension works everywhere you type on the web. The desktop app works across applications.
For writers who want deep feedback on their writing quality, not just error correction, Grammarly Premium is the strongest off-the-shelf option. The free tier is more limited but still useful for basic checking.
The tradeoffs:
Privacy. Every time you use Grammarly, your text goes to their servers. They process it remotely and return suggestions. They say they do not sell your data, which is true. But your text still leaves your device, lives on their infrastructure, and is subject to their data retention practices. For most use cases this is fine. For sensitive documents, it is something to think about. (I wrote a longer piece on this if you want the details.)
Cost. The free tier gets you basic grammar. The useful features (clarity, tone, rewriting) require Premium at around $30 per month on a monthly plan, or about $144 per year on annual billing. That is more than most productivity app subscriptions.
Requires internet. Grammarly does not have an offline mode. In airplane mode, it does not work. On a patchy connection, it is slow. This is structural, not a bug they can fix.
The gap: older iPhones and privacy-conscious writers
Here is the situation that neither Apple Intelligence nor Grammarly handles well:
You have an iPhone 14 or older. Apple Writing Tools does not run on your device. Grammarly works, but your text goes to their servers. You want real grammar checking, offline, on your phone, without an account or a subscription that costs more than Netflix.
That gap is why I built Proofed.
Proofed uses Apple Foundation Models on supported devices (iPhone 15 Pro+, iPhone 16+, all Apple Silicon Macs) for deep grammar and rewriting. On older devices, it falls back to a rules-based grammar engine that handles the common stuff: spelling, punctuation, obvious grammar errors, confused word pairs.
Everything runs on-device. No server. No account. No subscription required for the core grammar check.
The honest limitations: no browser extension, no desktop app, no long-term writing analytics. It is a focused tool for checking text on your iPhone, not a full writing platform. If you need the Grammarly feature set, Grammarly is still the answer.
But if you need something that works on your older iPhone, or you want your text to stay on your device, it is a real alternative.
How to pick
Use Apple Intelligence Writing Tools if:
- You have an iPhone 15 Pro or iPhone 16+
- You want basic proofreading built into the OS, no app required
- Your writing errors are mostly typos and simple grammar mistakes
Use Grammarly if:
- You write a lot and want deep feedback on style and clarity
- You need browser integration for web-based writing
- You are okay with cloud processing and the subscription cost
Use Proofed if:
- You have an older iPhone (or want it to work on all your devices)
- Your text is sensitive and you want it to stay on your phone
- You do not want to pay $30 per month for grammar checking
FAQ
Does Apple Intelligence replace Grammarly?
For basic grammar and spelling, it covers a lot of the same ground. For deeper features like tone analysis, clarity scores, and style suggestions, Grammarly still does more. They are not direct replacements. It depends on what you actually need from a grammar tool.
Is Apple Intelligence good enough for grammar?
Good enough depends on what you are writing. For emails and messages, usually yes. For professional documents, reports, or anything where writing quality matters, probably not on its own. It catches obvious errors but does not go deep on style or structure.
What if I have an older iPhone?
Apple Intelligence requires iPhone 15 Pro or iPhone 16+. If you have an iPhone 14 or older, you cannot use Writing Tools for grammar. Your options are Grammarly (cloud-based) or Proofed (on-device, works on iOS 17+).
Which is better for privacy, Apple Intelligence or Grammarly?
Apple Intelligence processes text on your device with no network calls. Grammarly sends your text to their servers. From a privacy standpoint, Apple Intelligence is the stronger choice if your device supports it.
Does Proofed work on iPhone 14?
Yes. Proofed runs on any iPhone with iOS 17 or later. On older devices that do not support Apple Foundation Models, it uses a rules-based grammar engine instead of on-device AI.
Proofed is available on the App Store. Runs on iOS 17+. No account. No internet required.