Japanese Font Subsetting Guide
Learn how to optimize Japanese fonts for the web. This guide covers Hiragana, Katakana, and Kanji subsetting to reduce file sizes by up to 90%.
Understanding Japanese Writing Systems
Japanese is unique because it uses three different writing systems. Each system serves a different purpose. Understanding them helps you make better subsetting decisions.
Hiragana is the basic Japanese script. It has 46 characters plus some variations. Japanese children learn this first. It is used for native Japanese words and grammar.
Katakana also has 46 characters. It looks more angular than Hiragana. Japanese uses it for foreign words, company names, and emphasis. Think of it like italics in English.
Kanji are Chinese characters used in Japanese. This is where the complexity comes in. There are over 50,000 Kanji characters in total. However, the Japanese government lists only 2,136 as commonly used. These are called Joyo Kanji.
Why Japanese Fonts Are Large
A complete Japanese font includes all three writing systems. It needs Hiragana, Katakana, and thousands of Kanji. This makes the font file very large.
Typical Japanese font sizes range from 5MB to 20MB. Compare this to English fonts at around 50-200KB. Loading such large files hurts your website performance badly.
Choosing the Right Character Set
The right character set depends on your website content. Here are the main options:
| Character Set | Characters | Best For |
|---|---|---|
| Hiragana + Katakana | ~200 | Logos, headings, children's content |
| JIS Level 1 | 2,965 | Most Japanese websites |
| Joyo Kanji | 2,136 | Educational content, newspapers |
| Custom Text | Varies | Static content, specific pages |
For most Japanese websites, the JIS Level 1 set works well. It covers nearly all characters used in everyday Japanese text.
How to Subset Japanese Fonts Step-by-Step
Follow these steps to create an optimized Japanese font subset using our free tool:
Go to the Font Subsetter
Open our Font Subsetter Tool in your browser. The tool works entirely online. No software installation needed.
Upload Your Japanese Font File
Drag your font file to the upload area. Or click to browse your computer. We accept TTF, OTF, WOFF, and WOFF2 files.
Popular Japanese fonts include Noto Sans JP, Noto Serif JP, and M PLUS fonts. Google Fonts offers many free Japanese fonts you can download.
Click Analyze Font (Recommended)
Click the purple Analyze button. The tool will scan your font and show coverage information. You will see which presets have the best support.
This helps you choose the right options. It shows how many characters each preset will include from your font.
Select the Japanese Preset
Find "Japanese" in the Quick Presets section. Click it to select. This includes Hiragana, Katakana, and common Kanji.
Also select "Basic Latin" if your site shows English text. Many Japanese websites mix Japanese and English content.
Add Custom Characters If Needed
Have specific text content? Paste it in the "From Text" box. The tool extracts all unique characters automatically.
This is useful for company names, product names, or specialized vocabulary. It ensures those exact characters are included.
Generate and Download
Click the orange "Subset Font" button. Wait a few seconds for processing. Your optimized font will download automatically.
Check the success message. It shows the original size, new size, and reduction percentage. Aim for at least 80% reduction.
Unicode Ranges for Japanese
For advanced users, here are the Unicode ranges for each Japanese script:
/* Hiragana */ U+3040-309F /* Katakana */ U+30A0-30FF /* Katakana Extended */ U+31F0-31FF /* CJK Unified (includes Kanji) */ U+4E00-9FFF /* Japanese Punctuation */ U+3000-303F /* Halfwidth Katakana */ U+FF65-FF9F
You can enter these in the Custom Ranges box. Separate multiple ranges with commas or new lines.
Best Practices for Japanese Web Fonts
Use WOFF2 Format
After subsetting, convert to WOFF2 for best compression. WOFF2 can reduce size by another 20-30%. Use our Font Converter for this.
Include Punctuation
Japanese uses unique punctuation marks. Characters like 。、「」（） look different from English versions. The Japanese preset includes these by default.
Consider Half-Width Characters
Japanese has both full-width and half-width versions of numbers and letters. Include the Halfwidth Forms range if you use these.
Test with Real Content
Always test your subsetted font with actual website content. Some rare Kanji might be missing. Check for boxes or question marks that indicate missing characters.
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Written by
Sarah Mitchell
With help & verified by language expert