Verified Nov 8, 2026
Overview of SIL Open Font License 1.1
The SIL Open Font License (OFL), version 1.1, is a dedicated open-source license authored by SIL International specifically tailored for digital typefaces and typographic software.
Traditional software licenses (such as the GNU GPL) were not originally designed for typographic art and often introduced ambiguity regarding whether documents embedding a font become subject to copyleft requirements. SIL OFL solves this problem by allowing open collaboration and unrestricted use in digital products while maintaining author attribution and preserving typographic integrity. The vast majority of fonts in Google Fonts and FontLens (including Pretendard and Inter) are governed by OFL 1.1.
Permission Summary by Use Case
| Use Case | Status | Practical Rule & Scope |
|---|---|---|
| Commercial Use | Allowed | Print publications, advertising, packaging, broadcast video, and digital media |
| Logo & Brand Mark | Allowed | Vector text and raster artwork in logos and corporate identities |
| Web Embedding | Allowed | Self-hosting as WOFF / WOFF2 via @font-face declarations |
| App Embedding | Allowed | Bundling font files directly into iOS, Android, macOS, or desktop software packages |
| Modification & Derivatives | Conditional | Derivative font software permitted, provided Reserved Font Names (RFN) are changed |
| Redistribution | Conditional | Permitted as long as copyright notices and the full OFL text remain attached |
| Standalone Sale | Prohibited | Selling the font file on its own as a standalone product is strictly disallowed |
Key Compliance Requirements
No Standalone Sale (Clause 1)
- The font software, whether original or modified, cannot be sold by itself. However, it can be bundled, redistributed, or sold with any software package or design suite.
Copyright & License Notice Preservation (Clause 2)
- When redistributing the font files or packaging them within applications, you must retain the author's copyright statement (
Copyright (c) ...) and the fullOFL.txtfile.
- When redistributing the font files or packaging them within applications, you must retain the author's copyright statement (
Reserved Font Name Restrictions (Clause 3)
- If the author specifies a Reserved Font Name (RFN), modified versions of the font cannot use that reserved name in their typeface family title without explicit written consent.
Reciprocal OFL Requirement (Clause 5)
- Any modified font files derived from an OFL font must also be distributed under the SIL Open Font License.
Notable Fonts in FontLens Under OFL 1.1
- Pretendard: Modern multi-script typeface optimized for Korean and Latin digital interfaces
- Inter: Carefully crafted UI variable typeface designed by Rasmus Andersson
- D2Coding: Monospaced font designed for readability in developer IDE environments
Official Source Text & Citations
SIL International maintains the official canonical text, version history, and detailed community interpretations:
- SIL OFL Official Project Site: https://openfontlicense.org/
- SIL International OFL 1.1 Canonical Text: https://scripts.sil.org/OFL
- Official OFL FAQ (Detailed Interpretations): https://scripts.sil.org/OFL-FAQ_web
