Convert OpenType (OTF) to WOFF Online Free
Convert OpenType font files to Web Open Font Format for use on websites. WOFF wraps your OTF data with zlib compression, producing smaller files optimized for web delivery while preserving all advanced OpenType typographic features.
By ChangeThisFile Team · Last updated: March 2026
To convert OTF to WOFF, drop your .otf file onto the ChangeThisFile converter. The font is parsed and repackaged as WOFF entirely in your browser using opentype.js. All CFF outlines, OpenType layout features, and kerning data are preserved with zlib compression applied. Free, private, no upload required.
Convert OpenType (OTF) to WOFF
Drop your OpenType (OTF) file here to convert it instantly
Drag & drop your .otf file here, or click to browse
Convert to WOFF instantly
OpenType (OTF) vs WOFF: Format Comparison
Key differences between the two formats
| Feature | OpenType (OTF) | WOFF |
|---|---|---|
| Outline format | CFF (Cubic Bezier curves) | Wraps CFF or TrueType outlines |
| Compression | None (raw data) | zlib compressed (30-50% smaller) |
| OpenType features | Full support (ligatures, stylistic sets) | All features preserved in wrapper |
| Browser support | Supported but suboptimal | Universal modern browser support |
| Primary use | Professional design and print | Web font delivery |
| File size | Larger uncompressed | Reduced by 30-50% via compression |
| Metadata | Standard OpenType name table | Extended metadata block available |
When to Convert
Common scenarios where this conversion is useful
Publishing OpenType fonts on the web
Convert professional OTF fonts to WOFF for use in @font-face rules. WOFF compression reduces file size while preserving all typographic features like ligatures and stylistic alternates.
Maintaining advanced typography on websites
OTF fonts often include sophisticated features like small caps, old-style figures, and contextual alternates. Converting to WOFF preserves these features for CSS font-feature-settings.
Cross-browser font compatibility
While raw OTF files work in some browsers, WOFF is the standard web font format with guaranteed cross-browser support and better caching behavior.
Preparing fonts for a design system
When building a web-based design system, convert your OTF brand fonts to WOFF to ensure consistent rendering across all team members' browsers and devices.
Who Uses This Conversion
Tailored guidance for different workflows
Web Developers
- Convert OpenType (OTF) fonts to WOFF for optimized loading on websites with @font-face declarations
- Transform OpenType (OTF) font files to WOFF for cross-browser compatibility in web projects
Graphic Designers
- Convert OpenType (OTF) fonts to WOFF for embedding in design tools or desktop publishing software
- Transform OpenType (OTF) font files to WOFF for use in print projects that require specific font formats
Typographers
- Convert OpenType (OTF) font files to WOFF for testing and previewing typefaces across different platforms
- Transform OpenType (OTF) fonts to WOFF for building multi-format font packages for distribution
How to Convert OpenType (OTF) to WOFF
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1
Drop your OTF file
Drag and drop your .otf font file onto the converter, or click to browse. OpenType fonts with CFF or TrueType outlines are both supported.
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2
Instant conversion
The font is parsed and wrapped in a WOFF container with zlib compression applied. All glyph outlines, OpenType layout tables, and kerning data are preserved.
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3
Download your WOFF file
Click Download to save the converted .woff file. Use it with @font-face in your CSS for optimized web font loading.
Frequently Asked Questions
Yes. All OpenType layout features — ligatures, stylistic alternates, small caps, old-style figures, contextual alternates — are preserved inside the WOFF wrapper. You can activate them via CSS font-feature-settings.
Yes. WOFF is a container format that compresses without altering the font data. CFF outlines render identically whether served as OTF or WOFF.
WOFF typically reduces OTF file size by 30-50%. CFF-based OTF fonts often compress well because CFF data has patterns that zlib handles efficiently.
For modern browsers, WOFF2 provides better compression. However, WOFF offers broader legacy support. Best practice is to generate both and use WOFF as a fallback format.
No. Converting file format does not alter licensing terms. If your OTF license allows web use, the WOFF version inherits the same permissions. Always verify your font's EULA.
Color font tables (COLR, CPAL, SVG) are included in the WOFF output if present in the original OTF. Browser support for color fonts in WOFF varies by the specific color table format.
No. The entire conversion process runs in your browser using opentype.js. Your font data never leaves your device, keeping proprietary and licensed fonts completely private.
OTF can contain either CFF (PostScript cubic curves) or TrueType (quadratic curves) outlines. Both types convert to WOFF successfully. CFF-based OTFs typically compress slightly better.
WOFF is designed for web browsers and most desktop applications cannot install WOFF fonts. Keep the original OTF for desktop use and use WOFF for your websites.
Yes. Both legacy kern table pairs and modern GPOS kerning data are preserved in the WOFF output, ensuring proper letter spacing in the browser.
Related Conversions
Need to convert programmatically?
Use the ChangeThisFile API to convert OpenType (OTF) to WOFF in your app. No rate limits, up to 500MB files, simple REST endpoint.
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