Mojisuu Character Counter is a free browser-based tool for counting Japanese text. Users paste or type text and instantly see character counts with and without spaces, line and paragraph counts, 400-character manuscript page estimates, and UTF-8 and Shift_JIS byte lengths. The text is processed locally in the browser and is not uploaded to a server, and no account is needed.
Who it is for
Japanese writers, editors and students who need to check a character limit, line and paragraph counts, or byte length before submitting their work.
Problem it solves
Japanese text is written without word spacing, so word-based counters and editors that show only a rough length make it hard to confirm a character limit, and pasting a draft into an online counter may upload it to a server.
The solution
Pasted text is counted in real time with and without spaces, alongside line count, paragraph count, 400-character manuscript page estimates and both UTF-8 and Shift_JIS byte lengths, so a submission limit can be checked in one place.
What makes it unique
Counting runs in the browser and the text is not uploaded to a server, so a draft can be checked without sending it anywhere, and manuscript-page conversion and Shift_JIS bytes are shown together with the usual character count.
Features4 listed
Count Japanese characters with and without spaces
Count lines and paragraphs in real time
Estimate 400-character manuscript pages
Show UTF-8 and Shift_JIS byte lengths
Details
Platforms
Web
Pricing
Free
Built for
Japanese writers, editors and students who need to check a character limit, line and paragraph counts, or byte length before submitting their work.
In IndieTools' mobile lab test on November 12, 2026, the Mojisuu Character Counter website scored 99 out of 100 (good). All 5 lab metrics were rated good. It placed #137 overall in the finalized week 2026-W45.
Measured (UTC)
LCPLargest Contentful Paint
901 ms
Good
TBTTotal Blocking Time
104 ms
Good
CLSCumulative Layout Shift
0.000
Good
FCPFirst Contentful Paint
901 ms
Good
Ranked #137 overall in 2026-W45, best #21.
Mojisuu Character Counter lab metrics
Speed metrics for Mojisuu Character Counter, measured November 12, 2026
Metric
Result
Status
Trend
Mobile lab testMid-range phone on a throttled 4G connection, two runs averaged. Changes compare with the run on Nov 11.
Performance score
GoodDown 1 points
99 / 100
GoodDown 1 points
First Contentful PaintFCP
GoodAbout the same
901 ms
GoodAbout the same
Largest Contentful PaintLCP
GoodAbout the same
901 ms
GoodAbout the same
Speed IndexSI
Good209 ms faster
907 ms
Good209 ms faster
Total Blocking TimeTBT
Good37 ms slower
104 ms
Good37 ms slower
Cumulative Layout ShiftCLS
GoodAbout the same
0.000
GoodAbout the same
Unthrottled observationsTimed on the test machine's own fast connection, so they read lower than the lab metrics above.
Page loadLoad
137 ms faster
558 ms
137 ms faster
Server responseTTFB
About the same
3 ms
About the same
Mojisuu Character Counter performance history
55 comparable mobile lab runs since September 27, 2026. Choose a metric and a range, then move along the line to read each run.
Mojisuu Character Counter Speed ranking
Weekly Speed standing for Mojisuu Character Counter
Weekly standingLatest finalized week 2026-W45. Bests cover the last 52 finalized weeks.
Stored lab observations from controlled test runs, not real-user Core Web Vitals or a guarantee of search rankings. Weekly standings remain attached to their finalized edition.Method psi-mobile-two-sample-mean-v1, 2 samples per reading. Lab results can vary between runs.
Model difference+9. DR4 is 9 points higher than DR3.
Measured · mojisuu.app
What do DR4, DR3 and the model difference mean?
DR4:
Ahrefs' newer model. It gives more weight to links from sites with organic search traffic and rates a subdomain on its own links.
DR3:
The previous model, shown in the Ahrefs app until 1 December 2026.
Model difference:
DR4 minus DR3 for the same domain. The models calculate differently, so this is not growth or a drop; the “since” lines compare each model with itself.
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