Variable Font Optimizer - Reduce Font File Size by 94% for Better Core Web Vitals
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Reduce font file size by up to 94%.
2.4 MB 144 KB
Trusted by teams at
See the Difference
Drag the slider to compare file sizes
Everything You Need
Professional-grade font optimization tools that run entirely in your browser.
Axis Instancing
Pin variable font axes to specific values. Eliminate unused variation data and dramatically reduce file size.
Glyph Subsetting
Keep only the characters you need. Remove unused glyphs to create lean, optimized font files.
Format Conversion
Convert TTF/OTF to WOFF2 for maximum web compression. Up to 30% smaller than WOFF.
100% Private
Your fonts never leave your browser. All processing happens locally using WebAssembly.
Lightning Fast
WebAssembly-powered processing delivers near-native performance. Optimize fonts in seconds.
Live Preview
See your changes in real-time. Preview text with your optimized font before downloading.
How Sift Compares
See why developers choose Sift over traditional font optimization tools.
| Feature | Sift | Font Squirrel | Google Fonts | Transfonter |
|---|---|---|---|---|
| Privacy (No Upload) | ||||
| Variable Font Support | ~ | ~ | ||
| Axis Instancing | ||||
| WOFF2 Output | ||||
| Self-Hosted | ||||
| GDPR Compliant | ? | ? |
See It In Action
A clean, powerful interface that makes font optimization effortless.
No sign-up required
Three Simple Steps
Optimize your fonts in under a minute. No account required.
Drop Your Font
Drag and drop any TTF, OTF, WOFF, or WOFF2 file. Variable fonts fully supported.
Configure Options
Select axis values, choose character sets, and pick your output format.
Download
Get your optimized font file instantly. Copy the CSS snippet and you're done.
Real Performance Gains
Measured results from actual font optimizations. See what Sift can do for your project.
Popular Font Benchmarks
| Font | Original | Optimized | Reduction |
|---|---|---|---|
| Inter Variable | 2.4 MB | 156 KB | -94% |
| Roboto Flex | 3.1 MB | 89 KB | -97% |
| Source Sans Variable | 1.8 MB | 124 KB | -93% |
| Playfair Display | 856 KB | 68 KB | -92% |
Dive Deeper: Font Performance Guides
Loved by Developers
Join thousands of developers shipping faster, lighter fonts.
"Saved 2MB on our main font bundle. Lighthouse performance score went from 74 to 96. Incredible tool."
"Finally a font optimizer that doesn't require uploading to sketchy servers. Privacy-first and blazing fast."
"We use Sift for every client project now. The WOFF2 output is perfectly optimized. A must-have in our workflow."
Privacy by Architecture
Your fonts never leave your browser. Here's exactly how it works.
Local Processing
Font files are processed entirely in your browser using WebAssembly. Zero server uploads.
Sandboxed Execution
HarfBuzz runs in isolated memory. No filesystem access, no network calls.
Verify It Yourself
Open DevTools → Network tab → Process a font. You'll see zero outbound requests. What happens in your browser stays in your browser.
Sound Familiar?
Whatever brought you here, Sift has you covered.
Launching a Rebrand?
New brand identity means new custom fonts. Ensure they load fast from day one.
Lighthouse Score Below 90?
"Ensure text remains visible during webfont load." Sound familiar? Fix it in seconds.
LCP Over 2.5 Seconds?
Fonts blocking your Largest Contentful Paint? Subset and self-host for instant gains.
Building a New Product?
Start with optimized fonts from the beginning. Don't inherit performance debt.
Standardizing a Design System?
Create consistent, optimized font packages across all your products and teams.
Cutting CDN Costs?
High-traffic sites pay per byte. Reduce font payloads by 90%+ and watch costs drop.
For Developers
Improve Core Web Vitals, generate @font-face CSS, reduce bandwidth costs, and keep fonts version-controlled.
For Designers
Preview any variable font, extract specific weights, prepare web-ready files, and ensure design-to-dev consistency.
Trusted by Performance-Focused Teams
See how developers and designers are improving their Core Web Vitals with optimized fonts.
"Reduced our Inter variable font from 312KB to 18KB. LCP dropped by 200ms and our Lighthouse performance score jumped from 74 to 96. This is exactly what we needed."
"Finally, a tool that understands variable fonts. I extracted only the weights my design system uses and the generated CSS is production-ready. Saves hours every project."
"We switched from Google Fonts to self-hosted optimized fonts using Sift. No more third-party requests, better privacy, and our bundle is 85% smaller. Brilliant tool."
Frequently Asked Questions
Ready to Optimize?
Start reducing your font file sizes today. No sign-up required.
Launch AppNo account needed · 100% free · Works offline