Kaisei Opti
Kaisei Opti is a serif font in 3 weights. Its lowercase letters are 7% wider than the typical serif font. Last updated 11 September 2025.
Editing a PDF that uses Kaisei Opti
Most PDFs embed only the letters they already use. Type a new letter and many editors either refuse or swap in a different font. MythosPDF recognises Kaisei Opti from the widths stored in your PDF, loads the complete open font, and sets your new text in Kaisei Opti itself. The rest of the page is carried over untouched.
Measured metrics
| Average lowercase letter width | 555.2 units per 1000 em |
|---|---|
| Average capital letter width | 722 units per 1000 em |
| Word space | 250 units per 1000 em |
| Digits | tabular (every digit is 590 units wide, so columns of numbers line up) |
| Spacing | proportional |
| Width of i compared with m | 37% |
| Printable ASCII characters covered | 94 of 94 |
| Category | Serif |
Weights and styles
Languages beyond basic Latin
Open fonts closest to Kaisei Opti
Measured on every printable character both fonts contain. A smaller difference means the same words take the same space, so lines break in the same places.
- Kaisei Decol Regularidentical letter widths (0 units)
- Kaisei Tokumin Regularidentical letter widths (0 units)
- Kaisei HarunoUmi Regularidentical letter widths (0 units)
- UoqMunThenKhung Regularidentical letter widths (0 units)
- Gelasio Regularloosely similar widths (39.4 units)
- PT Serif Caption Regularloosely similar widths (42.2 units)
- Laila Regularloosely similar widths (42.8 units)
- M PLUS 2 Regularloosely similar widths (43.5 units)
Compare Kaisei Opti
Questions people ask
+Can I edit a PDF that uses Kaisei Opti?
Yes. Drop the PDF into MythosPDF and click the text. New letters are set in Kaisei Opti itself, loaded from the open font, so the edit matches the rest of the page.
+Is Kaisei Opti free to use?
Kaisei Opti is released under the SIL Open Font License 1.1, an open licence that allows free use in documents, including commercial ones. Check the licence text for your exact use.
+Which font is closest to Kaisei Opti?
By measured letter widths, Kaisei Decol is the closest match among open fonts (a mean difference of 0 units per 1000 em). Text set in one takes almost the same space in the other.
+Which languages does Kaisei Opti support?
It includes these character sets: Cyrillic, Japanese, Latin, Central European.
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