kitio.aiGrammarly vs Duden Mentor
A side-by-side look at pricing plans, free tiers, features, pros and cons, updated for 2026. Grammarly starts at $30/mo and Duden Mentor starts at See pricing page. Check both pricing pages for current plans.
At a glance
Best for
Pricing model
Starting price
Free plan
Made by
Based in
Rating
Key features
- Grammar and spelling checks
- Tone detection
- Full-sentence rewrites
- Plagiarism checker
- Authorship tracking
- German spelling checks
- Grammar and punctuation
- Style tips
- Synonym suggestions
- Word add-in
| Feature | Grammarly | Duden Mentor |
|---|---|---|
| Best for | Grammar, tone and rewrite suggestions in almost every app you type in | German spelling, grammar and style checker from the Duden dictionary |
| Category | Writing | Writing |
| Pricing model | Freemium | Freemium |
| Starting price | $30/mo | See pricing page |
| Free plan | Yes | Yes |
| Made by | Superhuman Platform Inc. | Cornelsen Verlag |
| Based in | United States | Germany |
| Rating | No ratings yet | No ratings yet |
| Key features |
|
|
Pricing compared
Grammarly starts at $30/mo and Duden Mentor starts at See pricing page. Check both pricing pages for current plans.
Free plan
Cheapest paid plan
Top plan
Free trial
3 plans
Free
Free
- Spelling and grammar checks
- Tone detection
- 100 AI prompts
Pro
$30/mo
- Per member
- Full-sentence rewrites
- Tone adjustments
- Plagiarism and AI detection
Enterprise
Contact sales
- BYOK encryption
- Custom roles and permissions
- Data loss prevention
- Dedicated support
Prices in USD, checked Oct 28, 2026 or later. Plans change often, so confirm on each tool's site before you buy.
Pros and cons
Grammarly
- Works in nearly every app and website
- Free plan catches most basic errors
- Clear explanations for each suggestion
- Best features need the paid plan
- Can flatten a writer's personal style
- English only
Duden Mentor
- Follows Duden rules exactly
- Free basic checks
- Works in Word and browsers
- German only
- Style features need Premium
Which one should you choose?
Choose Grammarly if you want:
- Works in nearly every app and website
- Free plan catches most basic errors
- Clear explanations for each suggestion
Watch out: best features need the paid plan.
Choose Duden Mentor if you want:
- Follows Duden rules exactly
- Free basic checks
- Works in Word and browsers
Watch out: german only.
Grammarly vs Duden Mentor FAQ
What is the difference between Grammarly and Duden Mentor?
Grammarly: Grammar, tone and rewrite suggestions in almost every app you type in. Duden Mentor: German spelling, grammar and style checker from the Duden dictionary. Both are writing tools.
Is Grammarly or Duden Mentor cheaper?
Grammarly starts at $30/mo and Duden Mentor starts at See pricing page. Check both pricing pages for current plans.
Do Grammarly and Duden Mentor have free plans?
Grammarly: Yes. Duden Mentor: Yes.
Who makes Grammarly?
Grammarly is made by Superhuman Platform Inc., based in United States.
Who makes Duden Mentor?
Duden Mentor is made by Cornelsen Verlag, based in Germany.
Which should I choose, Grammarly or Duden Mentor?
Choose Grammarly if you value works in nearly every app and website and free plan catches most basic errors. Choose Duden Mentor if you value follows duden rules exactly and free basic checks.