Technical SEO
font-display
The font-display descriptor controls what a browser shows while a web font loads: block the text, show a fallback and swap, or never swap.
What is font-display?
The font-display descriptor controls what a browser shows while a web font loads: block the text, show a fallback and swap, or never swap. The swap value shows the fallback immediately and replaces it when the font arrives.
What it affects
It decides whether a slow font means invisible text or a visible layout shift, and both are measurable failures.
How it gets implemented
Set to swap for body and heading fonts, paired with a fallback whose metrics are close to the web font so the swap does not move the layout.
The common misunderstanding
Swap avoids invisible text and causes layout shift unless the fallback metrics are matched. Fixing one without the other just moves the problem.
Worth knowing because it comes up in almost every conversation about this.
Where this comes up in the work
It is part of AI Automation and Workflows, and more specifically of AI in the workflow. Across the rest of the work it shows up in:
- AI Automation and Workflows, where it sets the ceiling on working out which part of a process needs judgement and which does not
- AI Platform Optimization, because working the sub-questions a system asks itself, not only the headline query depends on it
- Agentic Commerce, in which it shows up as deep linking from an assistant answer to the exact variant rather than a category
- App Store Optimization, where it decides getting the developer page to support the app rather than sit there
What to check
Two questions that establish whether this is actually in order on a given site:
- Whether the measurement that would expose a problem is even being collected
- Whether a change to it would be noticed, or discovered a quarter later
Common questions
How would we know font-display is a problem?
By measuring it rather than by argument. Set to swap for body and heading fonts, paired with a fallback whose metrics are close to the web font so the swap does not move the layout.
Is font-display just another name for something?
Swap avoids invisible text and causes layout shift unless the fallback metrics are matched. Fixing one without the other just moves the problem.
Does font-display affect rankings directly?
Not on its own, and claims that it does are usually overselling. It decides whether a slow font means invisible text or a visible layout shift, and both are measurable failures. The evidence is in LinkedIn Ads management. The argument about what it means is in Meta Ads management.
How do you check font-display on a site?
Set to swap for body and heading fonts, paired with a fallback whose metrics are close to the web font so the swap does not move the layout. Two pages carry the detail this one summarises: Udaipur, and then Vancouver.
Who owns font-display in a business?
Whoever is accountable for making the category pages earn their position instead of listing products. Problems with this tend to persist because nobody is. A lot of the work here is really Manufacturing and industrial, with Marketplaces and platforms close behind.
How much work is font-display?
Less than people expect to check and sometimes more than they expect to fix. Set to swap for body and heading fonts, paired with a fallback whose metrics are close to the web font so the swap does not move the layout. If this is already in place, Content and Editorial and Conversion Rate Optimization are the next two things to fix.
Get a scoped answer rather than a proposal
Send what you have. We read it before the call, so the call is about decisions rather than discovery.