What is UFO?

UFO (Unified Font Object) is an open, XML-based font source format used by professional font editors for collaborative font development.

What is SFD?

Spline Font Database (SFD) is the native project file format for FontForge, an open-source font editor for font design.

When Should You Use UFO vs SFD?

Use UFO When...

Reach for UFO when your priority is font design and editing, collaborative font development, glyphs/robofont — its uncompromising quality ensures every detail is preserved.

Use SFD When...

Reach for SFD when your priority is font design and editing, fontforge projects — its uncompromising quality ensures every detail is preserved.

UFO vs SFD: Key Differences

•UFO uses lossless compression while SFD uses lossless compression — both take the same approach to file size management.
•Neither format changes compression philosophy — both are lossless compression — so any size differences are due to encoding efficiency, not a shift in quality approach.
•Transparency: N/A
•UFO files are typically 100KB to 10MB+ depending on glyph count while SFD files range Larger than production fonts due to editing metadata
•Primary audience: UFO is built for font design and editing, collaborative font development, glyphs/robofont scenarios, while SFD focuses on font design and editing, fontforge projects — pick the format that matches your output requirement.

Advantages of UFO

✓UFO uses lossless compression tailored for Font design and editing, collaborative font development, Glyphs/RoboFont.
✓UFO is supported natively on virtually every device, browser, and operating system.
✓UFO files are bit-for-bit perfect, preserving every pixel and sample for professional work.
✓UFO integrates seamlessly with all major creative tools and workflows.

Advantages of SFD

✓SFD uses lossless compression tailored for Font design and editing, FontForge projects.
✓SFD is supported natively on virtually every device, browser, and operating system.
✓SFD files are bit-for-bit perfect, preserving every pixel and sample for professional work.
✓SFD integrates seamlessly with all major creative tools and workflows.

Common Use Cases for UFO to SFD Conversion

Video subtitles
Game UI typography
Website typography
Brand identity
Print design
Mobile apps

Industry Applications

Book PublishingMobile App DevelopmentWeb DesignTypographyGraphic DesignDesktop Publishing

Best Practices for UFO to SFD Conversion

→Before converting UFO to SFD, review the font license — some licenses restrict format conversion
→Check hinting data after conversion: SFD may handle TrueType hinting differently than UFO
→Verify that all character sets (Latin, Cyrillic, CJK, etc.) survived the conversion intact
→Test the converted font in both a browser and a desktop application
→Keep the original font file in case the conversion alters spacing metrics

Troubleshooting UFO to SFD Conversion

!SFD font doesn't render correctly → check if SFD supports all glyphs present in UFO
!Licensing restrictions after UFO to SFD conversion → verify the font license allows format conversion
!Hinting data lost converting UFO to SFD → some font formats like SFD may not preserve TrueType hinting
!Special characters missing from converted SFD → font subsetting may have removed unused glyphs

Related Font Converters

All Font Formats

View all Font converters →

More Font tools

Convert to SFD →Convert from UFO →

Convert UFO to SFD Online - Free & Fast

Convert UFO files to SFD online for free. High-quality conversion with no registration required.

Font Converter

Upload or enter a URL to convert UFO to SFD instantly

Click to upload or drag & drop UFO file

or paste from clipboard

.ufo,.UFO (max 100MB)

SSL EncryptedAuto-deleted in 1 hourProcessed securelyNo registration needed

Verifying security check…

About UFO and SFD

UFO

UFO (UFO) - Unified Font Object, XML-based source format for font design and editing. Best for font design and editing, collaborative font development, glyphs/robofont.

SFD

SFD (SFD fonts) - Spline Font Database, FontForge native font editing format. Ideal for font design and editing, fontforge projects.

Format Comparison

CompressionLossless → Lossless

TransparencySupported

Use CaseConvert from font design and editing, collaborative font development, glyphs/robofont to font design and editing, fontforge projects

File Size~Larger than production fonts due to editing metadata after conversion

FAQs

Is converting UFO to SFD free?

Yes, GoConvertFile offers free conversion of UFO to SFD for files up to 100MB. No registration required.

How long does it take to convert UFO to SFD?

Most UFO to SFD conversions complete within seconds for standard-sized files. Larger files may take longer depending on the conversion complexity.

What is SFD best used for?

SFD is ideal for font design and editing, fontforge projects. Spline Font Database, FontForge native font editing format

What file size should I expect after converting UFO to SFD?

File size after UFO to SFD conversion depends on the content complexity and quality settings. Both formats use similar compression approaches so sizes are comparable.

Related Tools

View all font converter converters