Check Your Japanese. Instantly.
Paste any Japanese text below. Our AI flags grammar errors, wrong particles, unnatural phrasing — and explains exactly how to fix them.
Trusted by Japanese learners at every level — N5 beginners to N1 candidates
Real-time correction
Grammar, particles, vocabulary and formality — all checked in one pass.
Spaced repetition
Install the extension to revisit your mistakes with smart flashcard reviews.
JLPT-calibrated
Every check estimates the JLPT level of your writing so you can see progress.
About the free checker
What kind of errors does it catch?
Grammar errors (wrong verb conjugations, tense), incorrect particles (は vs が, に vs で), unnatural vocabulary choices, formality mismatches (casual vs polite), and phrasing that a native speaker would find unusual.
What JLPT levels does it support?
The checker works at all levels from N5 (beginner) to N1 (near-native). The AI estimates your writing level and calibrates its feedback accordingly.
How many checks can I do for free?
Up to 5 checks per hour with no account. Install the free Chrome extension or create a free account for 10 checks per day. Upgrade to Pro for 100/day.
How is this different from Google Translate?
Google Translate converts text between languages. ZISTICA MOJIIQ corrects Japanese you have already written — explaining each error and teaching the rule, so you actually improve over time.
What does ZISTICA MOJIIQ check?
The AI correction engine analyses five dimensions of your Japanese writing simultaneously, giving you actionable feedback beyond simple spell-checking.
Grammar errors
Wrong verb conjugations, incorrect tense, adjective form mistakes (い vs な), and te-form errors — flagged with the correct form and rule.
Particle accuracy
は vs が, に vs で, を vs に after potential verbs, から vs より — the particle errors that even intermediate learners repeat unconsciously.
Verb conjugation
Group 1, 2, and 3 verb form errors across all tenses and forms — including passive, causative, and potential form mistakes.
Naturalness score
Grammatically correct but unnatural phrasing is flagged. The AI suggests how a native speaker would express the same idea.
JLPT calibration
The checker estimates the JLPT level of your writing and calibrates explanations to vocabulary you already know — N5 through N1.
Questions about the checker
Can it check formal Japanese (keigo)?
Yes. The checker flags keigo inconsistencies — using humble forms where respectful forms are required, double-respectful errors (おっしゃられた), and mixing casual and polite registers.
Does it work with handwritten Japanese?
The checker works with typed Japanese text. For handwritten text, use your device's OCR (camera-to-text) app first, then paste the result.
Can I use it to practice for JLPT?
Yes — write Japanese sentences using grammar patterns you are studying, and the checker will flag errors with JLPT-calibrated explanations. It is particularly effective for N3–N2 grammar point practice.
What is the difference between this and a dictionary?
A dictionary tells you what words mean. ZISTICA MOJIIQ analyses the Japanese you have written and tells you what is wrong with it — explaining the grammar rule, showing the corrected form, and calibrating the explanation to your level.