Punctuation Checker

Detect punctuation issues in Japanese text: consecutive periods, too many commas, unterminated long sentences, and spacing errors.

Text to Check

How to Use

STEP 1
Paste the text you want to check into the input area.
STEP 2
Issues are automatically highlighted and categorized as Error, Warning, or Info.
STEP 3
Review the issue list and revise your text accordingly.

Rule-based detection may occasionally flag contextually correct expressions as errors.
Poetry, scripts, and other stylized writing intentionally use unusual punctuation. Use your judgment.

If a sentence has 4+ commas, consider splitting it into multiple sentences.

Japanese style guides generally recommend ≤80–100 characters per sentence.

Use this tool for a final check before sending business emails or official documents.

Q1
Are '、' and '，' treated the same?
Yes. Both are treated as Japanese commas and checked with the same rules.
Q2
Can I check English text?
This tool is designed for Japanese punctuation rules. Some rules may not apply to English text.
Q3
What is a good comma count per sentence?
Generally, 2–3 commas per sentence is considered readable. Four or more can make text feel run-on.