methodology / Performance / #36
Font loading strategy (FOUT/FOIT/swap)
#36 · Recommended · Web Quality · weighted · Performance · weight 0.7% · impl implemented · method v1.2.0
Web Quality factor
This factor is part of Web Quality — the weighted 0..100 score that sits above Web Standards. Its weight depends on what kind of site is being measured. Web Standards items take priority; this factor only enters the score once Web Standards passes.
- Base weight
- 0.7 applied to every site type unless overridden below
- Why this weight
- Font loading strategy — FOIT punishes readers; swap is the right default.
Per-site-type overrides
| Site type | Weight | Δ vs base |
|---|---|---|
| News / Publisher | 0.9 | +0.2 |
| Personal site | 0.4 | -0.3 |
| Media / Streaming | 0.9 | +0.2 |
Site types not listed inherit the base weight.
What this means for your business
If custom fonts aren't set up right, your headlines stay blank for a second or two — visitors see a flash of nothing where your name should be, then bounce. The fix is one line of code at the font.
Plain title: Your text shows up while fonts load
What we measure
Custom fonts can either delay your page rendering (FOIT — flash of invisible text) or flash unstyled text (FOUT). `font-display: swap` shows fallback text immediately, then swaps in the custom font when it loads.
How to improve your score
Add `font-display: swap` to your `@font-face` rules, or ensure your font loader (Google Fonts, Adobe Fonts, @fontsource) uses it by default.
Facts
Implementation notes
Parse stylesheets for `font-display` declarations and report the value.
Scoring
Scoring formulas are versioned with the methodology. The current method (v1.2.0) maps raw measurements to pass, warn, fail. Factor weights determine how much each contributes to the composite — see the methodology index for the full table.
Cited by these standards
Standards in the Standards Library whose satisfiedBy requirement tree references this factor. Each link goes to the standard's full entry — methodology, scope, and the other factors it relies on.
Version history
| Version | Change | Date |
|---|---|---|
| v1.2.0 | Factor introduced. Status: live. Scoring impl: implemented. | 2026-04-25 |