Overview

Mojisuu (mojisuu.app), whose name means "character count" in Japanese, is a free Japanese-language character counter. You type or paste text and it shows the character count, lines and byte size in real time. The site states that input is processed inside the browser and never sent to a server, and it works on phones, tablets and computers.

What it counts

Characters including spaces and line breaks, and characters excluding them, shown side by side. Full-width (zenkaku) spaces are treated as spaces.
Lines and paragraphs.
Genkō yōshi manuscript sheets: characters without spaces divided by 400, shown as an exact value and rounded up to whole sheets.
Byte counts in both UTF-8 and Shift_JIS. If a character cannot be converted to Shift_JIS, the tool shows a dash and tells you how many characters are affected instead of giving a partial figure.

On supported browsers, emoji and combined characters are counted the way they look on screen, as one character; when it falls back to a compatibility mode, it says so.

Target limits

You can set a target or maximum, either a custom number or a preset for common social limits: X (formerly Twitter) at 140 full-width or 280 half-width characters, Instagram captions at 2,200, Instagram profiles at 150 and Threads posts at 500.

When counts do not match

A helpful section explains why results may differ from Word, Google Docs or a submission form: check first whether spaces and line breaks are counted, then look at emoji, combined characters and Shift_JIS-incompatible characters. The site links to guides on counting in Word and Google Docs, using Excel's LEN and LENB functions, setting limits in Google Forms, and a separate counter for school essays and manuscript paper rules. It also publishes a comparison of how major English counters treat spaces and line breaks.

Pricing

Free to use with no account.

Who it suits

Students writing reports and essays to a character limit, job seekers filling in entry sheets, writers working with manuscript paper, social media users and developers checking byte limits in forms and systems.

Pros: shows both counting rules at once; UTF-8 and Shift_JIS byte counts; text never leaves the browser.
Cons: Japanese-only interface; a focused counter without grammar or style checks; emoji counting depends on browser support.