kitio.aiLanguageTool vs Duden Mentor
A side-by-side look at pricing plans, free tiers, features, pros and cons, updated for 2026. LanguageTool starts at See pricing page 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
- Checks 30+ languages
- Browser and Office add-ins
- AI paraphraser
- Personal dictionary
- Self-hostable engine
- German spelling checks
- Grammar and punctuation
- Style tips
- Synonym suggestions
- Word add-in
| Feature | LanguageTool | Duden Mentor |
|---|---|---|
| Best for | Multilingual grammar and style checker for more than 30 languages | German spelling, grammar and style checker from the Duden dictionary |
| Category | Writing | Writing |
| Pricing model | Freemium | Freemium |
| Starting price | See pricing page | See pricing page |
| Free plan | Yes | Yes |
| Made by | Learneo | Cornelsen Verlag |
| Based in | Germany | Germany |
| Rating | No ratings yet | No ratings yet |
| Key features |
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Pricing compared
LanguageTool starts at See pricing page and Duden Mentor starts at See pricing page. Check both pricing pages for current plans.
Free plan
Cheapest paid plan
Top plan
Free trial
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
LanguageTool
- Strong support for European languages
- Open-source core
- Works in LibreOffice
- Free plan limits text length
- Style suggestions weaker than in English-only tools
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 LanguageTool if you want:
- Strong support for European languages
- Open-source core
- Works in LibreOffice
Watch out: free plan limits text length.
Choose Duden Mentor if you want:
- Follows Duden rules exactly
- Free basic checks
- Works in Word and browsers
Watch out: german only.
LanguageTool vs Duden Mentor FAQ
What is the difference between LanguageTool and Duden Mentor?
LanguageTool: Multilingual grammar and style checker for more than 30 languages. Duden Mentor: German spelling, grammar and style checker from the Duden dictionary. Both are writing tools.
Is LanguageTool or Duden Mentor cheaper?
LanguageTool starts at See pricing page and Duden Mentor starts at See pricing page. Check both pricing pages for current plans.
Do LanguageTool and Duden Mentor have free plans?
LanguageTool: Yes. Duden Mentor: Yes.
Who makes LanguageTool?
LanguageTool is made by Learneo, based in Germany.
Who makes Duden Mentor?
Duden Mentor is made by Cornelsen Verlag, based in Germany.
Which should I choose, LanguageTool or Duden Mentor?
Choose LanguageTool if you value strong support for european languages and open-source core. Choose Duden Mentor if you value follows duden rules exactly and free basic checks.