Source Sans 3
Source Sans 3 is a sans serif font in 8 weights with italics, also available as a variable font. Its lowercase letters are 8% narrower than the typical sans serif font. Last updated 5 September 2025.
Editing a PDF that uses Source Sans 3
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 Source Sans 3 from the widths stored in your PDF, loads the complete open font, and sets your new text in Source Sans 3 itself. The rest of the page is carried over untouched.
Measured metrics
| Average lowercase letter width | 474.9 units per 1000 em |
|---|---|
| Average capital letter width | 569 units per 1000 em |
| Word space | 200 units per 1000 em |
| Digits | tabular (every digit is 497 units wide, so columns of numbers line up) |
| Spacing | proportional |
| Width of i compared with m | 30% |
| Printable ASCII characters covered | 94 of 94 |
| Category | Sans serif |
Weights and styles
- Source Sans 3 ExtraLight Italic
- Source Sans 3 ExtraLight
- Source Sans 3 Light Italic
- Source Sans 3 Light
- Source Sans 3 Italic
- Source Sans 3 Regular
- Source Sans 3 Medium Italic
- Source Sans 3 Medium
- Source Sans 3 SemiBold Italic
- Source Sans 3 SemiBold
- Source Sans 3 Bold Italic
- Source Sans 3 Bold
- Source Sans 3 ExtraBold Italic
- Source Sans 3 ExtraBold
- Source Sans 3 Black Italic
- Source Sans 3 Black
Languages beyond basic Latin
Open fonts closest to Source Sans 3
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.
- Source Sans Pro Regularidentical letter widths (0 units)
- Mada Regularidentical letter widths (0 units)
- Assistant Regularnearly identical widths (2.6 units)
- Varta Regularnearly identical widths (2.9 units)
- Tirra Regularvery close widths (12.8 units)
- Akatab Regularvery close widths (12.8 units)
- Chiron Hei HK Regularsimilar widths (22.7 units)
- Kedebideri Regularsimilar widths (23.3 units)
Compare Source Sans 3
Questions people ask
+Can I edit a PDF that uses Source Sans 3?
Yes. Drop the PDF into MythosPDF and click the text. New letters are set in Source Sans 3 itself, loaded from the open font, so the edit matches the rest of the page.
+Is Source Sans 3 free to use?
Source Sans 3 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 Source Sans 3?
By measured letter widths, Source Sans Pro 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 Source Sans 3 support?
It includes these character sets: Cyrillic, Cyrillic Extended, Greek, Greek Extended, Latin, Central European, Vietnamese.
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