Seymour One
Seymour One is a sans serif font in 1 weight. Its lowercase letters are 61% wider than the typical sans serif font. Last updated 16 September 2025.
Editing a PDF that uses Seymour One
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 Seymour One from the widths stored in your PDF, loads the complete open font, and sets your new text in Seymour One itself. The rest of the page is carried over untouched.
Measured metrics
| Average lowercase letter width | 837.6 units per 1000 em |
|---|---|
| Average capital letter width | 1066.5 units per 1000 em |
| Word space | 234.9 units per 1000 em |
| Digits | proportional (digit widths differ) |
| Spacing | proportional |
| Width of i compared with m | 34% |
| Printable ASCII characters covered | 94 of 94 |
| Category | Sans serif |
Weights and styles
Languages beyond basic Latin
Open fonts closest to Seymour One
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.
- Goblin One Regularloosely similar widths (96.7 units)
- Vast Shadow Regularloosely similar widths (98.9 units)
- Oi Regularloosely similar widths (103.1 units)
- Sonsie One Regularloosely similar widths (103.4 units)
- Climate Crisis Regularloosely similar widths (104 units)
- Geostar Regularloosely similar widths (106.6 units)
- Unbounded Regularloosely similar widths (107.6 units)
- Geostar Fill Regularloosely similar widths (107.6 units)
Compare Seymour One
Questions people ask
+Can I edit a PDF that uses Seymour One?
Yes. Drop the PDF into MythosPDF and click the text. New letters are set in Seymour One itself, loaded from the open font, so the edit matches the rest of the page.
+Is Seymour One free to use?
Seymour One 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 Seymour One?
By measured letter widths, Goblin One is the closest match among open fonts (a mean difference of 96.7 units per 1000 em). Text set in one takes almost the same space in the other.
+Which languages does Seymour One support?
It includes these character sets: Cyrillic, Latin, Central European.
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