Grammarly Keyboard Review: Writing Professional Messages on Mobile
An honest review of the Grammarly keyboard for iOS and Android — what it catches on mobile, where it falls short, and whether it's worth using for work.
The Grammarly keyboard is worth installing on your phone if you regularly write professional messages from mobile — emails, Slack messages, Teams chats, LinkedIn replies. It catches grammar errors and offers tone suggestions directly in your keyboard, without switching apps. The limitations are real: it doesn’t catch as much as the desktop extension, the suggestions interface is smaller and harder to use, and the keyboard switching friction bothers some users. For non-native speakers who write professionally from their phone, it’s a net positive.
What the Grammarly Keyboard Actually Does
The Grammarly keyboard replaces your phone’s default keyboard (iOS or Android) with a custom keyboard that includes:
Real-time grammar checking. As you type, underlines appear under suspected errors. Tap the underlined word or phrase to see the suggestion.
Tone detection. For longer messages, a tone indicator shows whether your message reads as confident, uncertain, or neutral. Less precise than the desktop version but functional.
Synonym suggestions. Tap a word to see alternatives. Useful when you know you’re using the same word repeatedly.
Spell correction. Like every smartphone keyboard, but with Grammarly’s vocabulary rather than your phone’s default.
Autocorrect. Standard autocorrect that you can customize to reduce the annoying “corrections” phone keyboards make.
How It Compares to the Desktop Extension
The desktop extension is better in every functional dimension — that’s the honest assessment. It catches more types of errors, the suggestions interface is larger and easier to navigate, and it integrates more deeply with email clients and document editors.
The mobile keyboard is valuable specifically because it’s on your phone — where you’re writing Slack replies, WhatsApp professional messages, LinkedIn comments, and quick emails when you’re away from your desk.
| Feature | Desktop Extension | Mobile Keyboard |
|---|---|---|
| Grammar correction | Comprehensive | Good but less thorough |
| Tone detection | Detailed | Basic |
| Clarity suggestions | Full range | Limited |
| Integration | Native in email/docs | Works in any text field |
| Suggestion interface | Large, easy to read | Small, on keyboard |
| Best for | Long emails, documents | Quick messages, replies |
Installation: iOS vs. Android
iOS setup:
- Install Grammarly app from the App Store
- Go to Settings → General → Keyboard → Keyboards → Add New Keyboard
- Select “Grammarly”
- Tap Grammarly and enable “Allow Full Access” (required for the keyboard to work)
- Set Grammarly as your default keyboard or switch to it manually when needed
The “Allow Full Access” step is the one that makes some users uncomfortable. This permission allows the keyboard to transmit text to Grammarly’s servers for analysis. Grammarly’s privacy policy covers this data. If you’re writing highly sensitive content, this is worth factoring in — the same consideration as the desktop tool.
Android setup:
- Install Grammarly from the Google Play Store
- In the app, tap “Set Grammarly as keyboard”
- Enable Grammarly in your phone’s keyboard settings when prompted
- Grant the requested permissions
Android setup is slightly more streamlined than iOS because Android’s permission model is more flexible.
Real-World Test: A Professional Reply on Mobile
Here’s a common mobile writing scenario — a quick reply to a client asking about a project status:
What you type quickly: “Hi Sarah, just to let you know the project is going on schedule and we will deliver on friday. Let me know if you have question.”
What Grammarly flags:
- “just to let you know” → weak opener (tone suggestion: start more directly)
- “going on schedule” → unclear phrasing (suggest: “on schedule”)
- “on friday” → “on Friday” (capitalization)
- “have question” → “have any questions” (article error)
After accepting suggestions: “Hi Sarah, the project is on schedule and we’ll deliver on Friday. Let me know if you have any questions.”
That’s a meaningful improvement for a 10-second edit. The article error (“have question” → “have any questions”) is exactly the type of ESL error the keyboard is good at catching — it’s a subtle grammatical issue that non-native speakers often miss because it sounds fine in many other languages.
What the Grammarly Keyboard Misses
The keyboard doesn’t catch everything the desktop extension does:
- Complex tone calibration. It won’t tell you that your reply to the angry client might be coming across as dismissive, not just grammatically.
- Long-form structure. If you’re writing a 300-word email on your phone, the keyboard won’t suggest structural improvements.
- Document-level analysis. No overall readability score or writing goals for mobile messages.
- Subject line optimization. No email subject line analysis.
For quick replies (under 100 words), the keyboard covers most of what you need. For long emails drafted on mobile, consider Grammarly’s full mobile app (app.grammarly.com accessed through your phone browser, or the Grammarly app itself) which gives you the full editing experience.
Battery and Performance Impact
Some users report slightly faster battery drain when using the Grammarly keyboard because it’s processing text through a server connection rather than purely locally. In practice, for most users, the difference is negligible — comparable to any other keyboard app that includes cloud features.
Performance is generally smooth on modern phones. On older devices (3+ years), you may notice a brief delay when suggestions load.
Privacy Note for Work Phones
If your company issued your phone and manages it through MDM (Mobile Device Management), check your company’s app policy before installing Grammarly. Some corporate MDM policies restrict which keyboards can be installed on managed devices.
For personal phones used for work, the privacy considerations are the same as the desktop tool — Grammarly processes your text. For most professional content, this is acceptable. For confidential information, be cautious.
For a complete picture of Grammarly’s features across all platforms, see our Grammarly review and Grammarly free vs. Premium comparison.
FAQ
Does the Grammarly keyboard work for WhatsApp?
Yes. The Grammarly keyboard works in any app that uses your phone’s keyboard — WhatsApp, Telegram, SMS, email apps, Slack, LinkedIn, Twitter/X, and more. You type in those apps and Grammarly’s keyboard is what you’re using.
Does Grammarly keyboard require Premium?
The basic keyboard works with a free Grammarly account. Some advanced features — detailed tone analysis and more comprehensive suggestions — require Grammarly Premium. The free keyboard still catches grammar errors and basic issues.
Can I switch between Grammarly and my default keyboard?
Yes. On both iOS and Android, you can switch keyboards at any time using the globe or keyboard icon on the keyboard itself. Many users keep Grammarly as their default and switch to their standard keyboard only for tasks where they don’t want it active.
Does Grammarly keyboard work in different languages?
The Grammarly keyboard checks English text. It won’t provide corrections if you’re writing in another language, though it will still function as a keyboard. If you write professionally in multiple languages, you’ll want a keyboard that supports your other languages for non-English messages.
Is the Grammarly mobile app the same as the keyboard?
No. The Grammarly mobile app is a standalone editor where you can paste text for full analysis. The Grammarly keyboard is a system keyboard replacement that works inline wherever you type. For the best mobile experience, install both — the keyboard for quick messages, the app for longer documents.