Results of our English-language spell checker comparison: Mimir Mentor scored 24 out of 25 points, Grammarly 19, LanguageTool 18, Linguix 17 and Scribbr 15. All five tools checked the same English test text, with spelling, grammar, punctuation and academic wording assessed. This is our own comparison, and Mimir Mentor is both the publisher and one of the providers compared. The scores apply to this text and the test conditions, not to every academic paper, language or current product version.
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| Spell Checker | Rating | Spelling & Grammar | Non-Academic Language | Citation Check | Plagiarism Check | AI Suggestions | Costs |
|---|---|---|---|---|---|---|---|
| Mimir Mentor | 24/25 | ✔ | ✔ | ✔ | ✔ | ✔ | Starts at 0€ |
| Grammarly | 19/25 | ✔ | ✖ | Partly (Citation Finder) | ✔ | ✔ | Starts at 0€ |
| LanguageTool | 18/25 | ✔ | ✖ | ✖ | ✖ | ✔ (paraphrasing) | Starts at 0€ |
| Linguix | 17/25 | ✔ | ✖ | ✖ | ✔ (paid credits) | ✔ | Starts at 0€ |
| Scribbr | 15/25 | ✔ | ✖ | ✖ | ✔ (separate paid product) | ✖ | Starts at 0€ |
Score colours: green 20–25, orange 10–19, red 0–9 points. The score is not an accuracy percentage for other texts.
✔ means the provider offers the feature in some form, including as a separate or paid add-on. The scores rate the spell check itself. We ran the test in early 2025 and updated the feature overview in September 2026.
Mimir Mentor (24/25)
Mimir Mentor excelled in our test with 24 out of 25 points.
Spelling & Grammar: Mimir Mentor automatically checks spelling and grammar and provides improvement suggestions.
Academic Text Correction: Mimir Mentor offers specialized features for improving academic writing, identifying filler words and incorrect citations.
Non-Academic Language: Mimir Mentor highlights informal or imprecise expressions and suggests alternatives, helping users improve their academic writing skills.
Integrated Plagiarism Check: Mimir Mentor includes an integrated plagiarism and citation checker to check your referencing and help detect potential plagiarism, a crucial aspect of academic integrity.
Data Protection: Mimir Mentor is GDPR-compliant and runs on servers in the European Union. Submitted documents are deleted after 30 days at the latest and never added to a public database. Over 70,000 students use it.
AI-Powered Suggestions: For more complex problems, Mimir Mentor can suggest an AI rewrite of the whole sentence.
- Outstanding performance in spelling and grammar correction
- Specialized features for academic texts
- Integrated check for plagiarism and correct citations
- AI suggestions for more complex issues
- Free plan limited to 5,000 characters; AI correction and the AI plagiarism check require Pro
Test Mimir Mentor with your own text:
Grammarly (19/25)
Grammarly scored 19 out of 25 points in our test.
Grammarly offers solid performance in spelling and grammar checking and also includes a plagiarism checker. However, it shows weaknesses in identifying non-academic language and occasionally delivers inconsistent results, making it less reliable for academic texts.
- Good performance in spelling and grammar
- Semi-integrated plagiarism checker
- Weaknesses in detecting non-academic language
- Occasionally inconsistent results
LanguageTool (18/25)
LanguageTool scored 18 out of 25 points in our test.
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It offers a reliable tool for spelling and grammar corrections but cannot match the level of specialized features provided by Mimir Mentor.
- Solid performance in spelling and grammar checking
- Almost no false positives
- Weaknesses in handling academic texts; no plagiarism or citation check
Linguix (17/25)
Linguix scored 17 out of 25 points in our test.
Linguix provides reliable performance in spelling and basic grammar checks but struggles with more advanced grammatical structures. It does not detect non-academic language, and its plagiarism check costs extra credits. Some deliberately embedded errors were counted twice, leading to more errors being flagged than actually present.
- Solid performance in spelling and basic grammar
- Weaknesses with detection of non-academic language
- Plagiarism check only with paid credits
Scribbr (15/25)
Scribbr scored 15 out of 25 points in our test.
It offers basic functionality for spelling and grammar checking but has weaknesses in handling academic texts and more complex grammar.
- Solid performance in spelling and grammar checking
- Lacks specialized features for academic texts; plagiarism check only as a separate paid product
- Weaknesses in addressing complex grammar issues
- No comprehensive description of found issues
Conclusion
In our test, Mimir Mentor scored highest (24 of 25 points). Its main advantage for students is the combination of spelling and grammar checks with academic style hints, a citation check and a plagiarism check in one place. If you only need a quick check of everyday texts, the free versions of the other tools can be enough.
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Test method and limitations
Importance of Spell Checkers
Spell checkers are more than simple tools; they are essential helpers for creating high-quality texts. They help avoid embarrassing errors and can even improve writing skills.
Test setup
Before diving into the specific features and performances of different spell checkers, it’s important to understand the test design.
As test text, we used the first part of the Wikipedia article on “Spell checker” and added a few extra errors.
We evaluated the tools on their ability to identify spelling, grammar, and punctuation errors. Additionally, we looked for stylistic improvement suggestions and checks for non-academic language.
All five tools checked the same text. A single English test text cannot show how a tool performs on every kind of academic paper, so treat the scores as an indication rather than a final verdict.
This English-language comparison is a separate test from our German-language comparison. Its providers and scores differ. Results must not be transferred from one test language to another.
FAQs
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What is the best spell checker of 2026?
In our test (run in early 2025, features updated in September 2026), Mimir Mentor scored highest with 24 of 25 points.
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Which spell checker is best for academic texts?
In our test, Mimir Mentor scored best because it combines spelling and grammar checks with hints on non-academic wording. It also offers a citation check and a plagiarism check.
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Why is a good spell checker important?
A reliable spell checker helps avoid embarrassing mistakes and can improve writing skills. For academic texts, specialized tools also flag informal wording and citation problems.
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Is there a free spell checker for academic writing?
Yes. All five tools in our test have a free version. Mimir Mentor’s free plan checks up to 5,000 characters with basic correction; AI correction and the plagiarism check are part of Pro.
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