Let's be honest. German grammar rules might be brutal at times and you might need some help fixing these grammar errors. Recognizing and correcting these mistakes is an effective practice method for mastering grammar. If you want to notice and correct your mistakes, you can use online grammar checkers.

In this article, we will review the best German grammar checker tools and discuss which German grammar tool will improve your language skills more.


  • Duden and LanguageTool are two excellent online tools for checking German Grammar.
  • Duden Mentor has features such as spelling & grammar checks and synonyms. (costs €9.95 per month)
  • LanguageTool has features such as spelling & grammar checking, paraphrasing, punctuation fixing, and a synonym checker. (costs €19.90 per month)
  • TextCortex outperforms both of these tools with more functionality and better pricing.

Duden Mentor

Duden Mentor has been a benchmark for improving dictionary quality for years. With Duden Mentor, you can check German spelling and grammar and improve the language quality of your text. Using generative AI and language models, Duden Mentor analyses your text and corrects potential spelling and grammar mistakes.

Using Duden Mentor, it is possible to identify and address grammar mistakes within up to 250 characters of writing, which can enhance adequate levels of language proficiency.

duden mentor german grammar checker

Who can Use Duden Mentor?

Duden Mentor is advantageous for anyone needing to sharpen their German language skills. If you are studying German as a second language, you can use Duden Mentor to boost your grammar and become better in spelling.

Duden Mentor is also a lifesaving tool for those working at start-ups or businesses where the written communication is in German. If you don't want spelling and grammar mistakes in your messages or emails you send to your colleagues or customers, you can use Duden Mentor.

Core Features

Duden Mentor provides a free spelling and grammar check of up to 250 characters. Duden Mentor proves itself to be reliable in its proofreading abilities, but it is particularly excellent at finding grammar mistakes within texts. It is an ideal option when someone needs a high-performing German grammar checker.

Premium plan for Duden Mentor unlocks new features for you. One of these features is the synonym finder. If you want to replace the words in your text with their synonyms, this feature is for you. You can also increase your vocabulary knowledge by using this feature. Knowing or using more than one word for an object/action verb/adjective will improve your language abilities.

Duden Mentor also has an extension for Chrome, Firefox, and Edge. With this extension, you can improve your writing style and take advantage of Duden's writing suggestions.

Duden Mentor Pricing

Duden Mentor has three different pricing plans: monthly, quarterly, and yearly. If you want to use Duden Mentor for a month, you must pay €9.95 (approximately $10.93). For the quarterly option, the cost is €23.85 (around $26.20) and for the annual plan, €83.40 (nearly $91.61).

duden mentor pricing


LanguageTool is a software that provides spelling and grammar checking services in 20+ languages, including German.

If you want your German text to be error-free, we advise checking out LanguageTool as an option.

LanguageTool deutsch Schreibassistent

Who can Use LanguageTool?

LanguageTool is a great choice for those who are dealing with numerous languages as it supports more than 20 languages. Not only this, but the grammar checker works on Windows, Mac and Linux, and can be installed in Chrome and Firefox browsers.

If you need to write an email in German, LanguageTool will come in handy for verifying its spelling and grammar accuracy.

LanguageTool Features

The main features of LanguageTool include:

• Spelling & grammar Checker

• Paraphrase

• Fix Punctuation

• Synonyms Checker

With all these features, you can be sure that your German text is error-free and of high quality.

LanguageTool Pricing

If you want to use all the features of LanguageTool without limits, you need to get its premium plan. LanguageTool offers four different premium plans;

• 2 Years – You will be charged $99 for the two-year license.

• Annual – You will be charged $59.90 for the one-year license.

• Quarterly – You will be charged $39 for the three-month license.

• Monthly – You will be charged $19.90 for the one-month license.

Best Alternative as a German Grammar Checker: TextCortex

TextCortex comes as an All-In-One AI assistant designed to help you with various writing tasks, including spelling and grammar checks. TextCortex is available as a web application and browser extension. You can easily fix your article's spelling and grammar wherever you are working on; all you must do is highlight the text you want to check and choose Fix Spelling & Grammar template.

german grammar fix

We are enabling everyone to write and work more efficient. No more bottlenecks with silly mistakes. All grammar errors fixed in a matter of seconds. You just focus on what is important and creating more.

Translate to/from German

With TextCortex, you can translate your texts to/from German with one click. Simply highlight the text you want to translate and click the translate icon. Then you can select the target language and get the output you want in seconds.

Don't forget to select German as the output language to use all of TextCortex's features, such as paraphrasing, summarizing, and expanding, in German!

TextCortex has unique features that you can use for German. It is possible to use every feature described in the rest of the article in German!

AI german translator

Zeno Assistant

Zeno Assistant is an AI-powered writing assistant developed to help you complete your writing tasks in 25+ languages. Its features include:

• Fix Spelling & Grammar

• Make Texts Longer/Shorter

• Simplify the Language of Your Text

• Creating Blog Posts/Essays/Outlines/Social Media Posts

• Find Action Items/Meeting Agendas 

• Summarize/Break Down/Rewrite

• Continue Writing 

You can use the ALT + ENTER (for Mac: OPTION + ENTER) shortcut to activate Zeno Assistant in Google Docs. You can also install our browser extension to try out Zeno Assistant on 2000+ platforms.

ZenoChat - Superior ChatGPT Alternative with up-to-date knowledge

TextCortex comes with the best conversational AI companion called ZenoChat. ZenoChat is an AI assistant to accompany you on 2000+ websites. You can also get the results you want by giving commands to ZenoChat. For example, if you enter the "fix spelling & grammar: [Your text]" prompt in ZenoChat, it will correct the spelling & grammar of your text for you.

Research faster with ZenoChat

ZenoChat has a great feature called web search. This feature allows it to access recent internet information. Thus, when you want information about current topics, Zeno can provide you with the most accurate information with cited sources. 

Fully Customizable AI Experience

Add your own personas to ZenoChat to make it sound like whomever you want. Or if you want to search from other data sources, be our guests and add your own data sources for Zeno to pull the information from such as your Notion Page, Google Drive files and so many more options.

ZenoChat allows you to immerse yourself with a fully-personalized AI experience.

If you are seeking an AI assistant that will help boost your efficiency and open doors for new possibilities, we suggest you give our AI companion a try!