Our web fonts are causing layout shifts (CLS) on load. Who optimizes font delivery for web performance?

Data as of Aug 25, 2026 · Based on 349 AI responses from ChatGPT Search and Google AI Mode · See how Parse measures this

Our web fonts are causing layout shifts (CLS) o… | Parse

Sources AI cites for this prompt

Source	Citation share
Optimize web fonts \| web.devhttps://web.dev/learn/performance/optimize-web-fonts	4.4%
Best practices for fonts \| Articles \| web.devhttps://web.dev/articles/font-best-practices	3.4%
Optimize Cumulative Layout Shift \| Articles - web.devhttps://web.dev/articles/optimize-cls	3.0%
Fixing Layout Shifts Caused by Web Fonts - DebugBearhttps://www.debugbear.com/blog/web-font-layout-shift	3.0%
How to avoid layout shifts caused by web fonts — Simon Hearnehttps://simonhearne.com/2021/layout-shifts-webfonts/	1.9%
The Ultimate Guide to Font Performance Optimization \| DebugBearhttps://www.debugbear.com/blog/website-font-performance	1.6%
Why Cumulative Layout Shift (CLS) Is Bad and 4 Ways to Fix It - Coralogixhttps://coralogix.com/guides/real-user-monitoring/cumulative-layout-shift-fix/	1.5%
Web Fonts and the Dreaded Cumulative Layout Shift \| Sentry Bloghttps://blog.sentry.io/web-fonts-and-the-dreaded-cumulative-layout-shift/	1.5%
Google's Layout Shift Culprits Insight: Use It to Fix Page Stabilityhttps://wp-rocket.me/google-core-web-vitals-wordpress/layout-shift/	1.4%
Measure And Optimize Cumulative Layout Shift (CLS) - DebugBearhttps://www.debugbear.com/docs/metrics/cumulative-layout-shift	1.3%

Recent AI responses to this prompt

The person/team you want is a **web performance engineer** or **front-end performance engineer**, ideally someone with **Core Web Vitals** expertise. A front-end engineer specializing in **font loading/typography performance** can also handle it. For your specific CLS issue, they should audit: - **Font loading…

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The person/team you want is a web performance engineer or front-end performance engineer, ideally someone with Core Web Vitals expertise. A front-end engineer specializing in font loading/typography performance can also handle it.

For your specific CLS issue, they should audit:

Font loading strategy — font-display, especially swap vs. optional.
Fallback font metrics — use CSS size-adjust, ascent-override, descent-override, and line-gap-override to make the fallback occupy nearly the same space as the web font.
Font delivery — serve compressed WOFF2, subset unused glyphs/weights, and ideally self-host.
Preloading — preload only the critical above-the-fold font, with crossorigin; over-preloading can hurt other performance metrics.
Actual field CLS — verify the improvement in real-user Core Web Vitals rather than relying only on Lighthouse.

So if you're hiring/searching for someone, I'd use “Web Performance Engineer / Core Web Vitals Specialist” rather than simply “font developer.”

If you want, I can also give you a job-description/search brief for finding the right freelancer or agency for this exact font-CLS problem.

Sources cited

Optimize web fonts | web.devweb.dev

Preload critical assets to improve loading speed | Articles | web.devweb.dev

Optimizing web font delivery to eliminate Cumulative Layout Shift (CLS) typically falls under the wheelhouse of **Front-End Engineers**, **Web Performance Specialists** , and **UX/UI Developers** . If you are looking to fix this internally or hire external help, here is a breakdown of who handles this and the core…

Read the full answer ▾

Optimizing web font delivery to eliminate Cumulative Layout Shift (CLS) typically falls under the wheelhouse of Front-End Engineers, Web Performance Specialists , and UX/UI Developers . If you are looking to fix this internally or hire external help, here is a breakdown of who handles this and the core techniques they use.

Who Optimizes Web Fonts?

Front-End / Web Performance Engineers: Developers who specialize in core web vitals, asset delivery pipelines, critical CSS, and browser rendering behavior.
Design Technicians / Typographic Engineers: Specialists who bridge the gap between brand design and engineering, managing font subsetting and licensing.
Agency / Freelance Web Optimizers: Consultants who audit sites using tools like Google PageSpeed Insights to diagnose layout shifts and rewrite asset-loading strategies.

How They Fix Font-Caused CLS

When web fonts cause a layout shift, it is usually due to either a FOIT (Flash of Invisible Text) or FOUT (Flash of Unstyled Text) where the fallback font metric doesn't match the custom font metric. Professionals resolve this using several standard techniques:

CSS @font-face Adjustments: Using modern override descriptors like size-adjust, ascent-override , and descent-override in CSS to scale fallback fonts so they match the exact dimensions of your custom web fonts.
Strategic font-display Usage: Setting font-display: swap paired with well-matched fallbacks, or font-display: optional to prevent late-loading layout reflows entirely.
Self-Hosting & Modern Formats: Moving away from third-party requests to self-hosted WOFF2 files, reducing latency and connection overhead.
Font Subsetting: Stripping out unused glyphs, characters, and weights you don't need (e.g., loading only Latin characters or specific numerical weights).
Resource Preloading: Adding <link rel="preload"> for critical fonts in the HTML <head> so the browser fetches them before parsing the CSS stylesheet.

If you want, tell me:

Are you self-hosting your fonts or using a provider like Google Fonts?
What tech stack or framework is your website built on?

I can share a quick code snippet or strategy to help you fix the CLS right away.

Sources cited

7 proven ways to optimize web fonts for faster loading. | Monotype.monotype.com

Optimize Cumulative Layout Shift | Articles | web.devweb.dev

Optimize web fonts | web.devweb.dev

Web Font Performance Checklist - DEV Communitydev.to

When web fonts cause Cumulative Layout Shift (CLS), it usually happens because the browser falls back to a default system font while the custom web font is downloading, and then swaps it out. When the custom font finally renders, its dimensions (line height, character width) differ from the fallback font, causing text…

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Fixing this isn’t typically handled by a separate company or external service; rather, it is a technical optimization solved by front-end engineers, web performance specialists, or UI/UX developers.

Who Fixes It?

Front-End / Web Performance Developers: They implement code-level fixes, CSS adjustments, and asset delivery pipelines.
Designers (Collaborating with Devs): Designers often need to approve fallback font metrics or adjust line-height pairings.

Key Technical Strategies to Eliminate Font CLS

Developers use a combination of CSS APIs and hosting strategies to stop fonts from shifting the layout:

- Setting `font-display: swap` prevents invisible text, but can cause a layout shift when the font swaps.
- Setting `font-display: optional` or `font-display: fallback` tells the browser to use the fallback font immediately and only switch to the custom font if it downloads quickly enough, preventing late layout shifts.[](https://www.monotype.com/resources/expertise/optimize-web-fonts-faster-loading) [[1]](https://www.monotype.com/resources/expertise/optimize-web-fonts-faster-loading)

- Modern CSS allows you to tweak fallback fonts so they match the exact dimensions of your custom web fonts. By using descriptors like `@font-face` properties for `size-adjust`, `ascent-override` , and `descent-override` , the fallback font takes up the exact same physical space as your custom font, reducing CLS to zero during the swap.[](https://web.dev/articles/optimize-cls) [[1]](https://web.dev/articles/optimize-cls)

- Instead of relying on third-party requests (like Google Fonts or Adobe Fonts) which add DNS lookup and connection overhead, host your font files (`.woff2` ) locally on your own origin or CDN.
- Add a `<link rel="preload">` tag in your HTML `<head>` for critical font files so the browser downloads them immediately during the initial document parse.[](https://www.youtube.com/watch?v=ijZc3l6Cci8&t=129) [[1]](https://www.youtube.com/watch?v=ijZc3l6Cci8&t=129)[[2]](https://www.monotype.com/resources/expertise/optimize-web-fonts-faster-loading)[[3]](https://www.youtube.com/watch?v=TETAY3YV8-o&t=170)

- Limit the number of heavy font weights (e.g., loading only 400 and 700 instead of six different weights).
- Use **glyph subsetting** to strip out unused characters, languages, or symbols, drastically shrinking the file size so it finishes downloading before the page layout settles.[](https://www.monotype.com/resources/expertise/optimize-web-fonts-faster-loading) [[1]](https://www.monotype.com/resources/expertise/optimize-web-fonts-faster-loading)

If your site is built on a specific platform (like WordPress, Next.js, Shopify, or a custom stack ), let me know and I can guide you on the exact plugins, configuration steps, or code snippets needed to fix your CLS.

Sources cited

Optimize Cumulative Layout Shift | Articles | web.devweb.dev

How to Improve Cumulative Layout Shift (CLS) on WordPressyoutube.com

7 proven ways to optimize web fonts for faster loading. | Monotype.monotype.com

Improve WordPress Speed: Load Google Fonts Locallyyoutube.com

The role you’re looking for is usually a **Web Performance Engineer / Front-End Performance Engineer**, often with a specialization in **Core Web Vitals and font loading**. For your specific CLS issue, they’d typically optimize: - **Font loading strategy:** `font-display: swap`, `fallback`, or `optional` to avoid…

Read the full answer ▾

The role you’re looking for is usually a Web Performance Engineer / Front-End Performance Engineer, often with a specialization in Core Web Vitals and font loading.

For your specific CLS issue, they’d typically optimize:

Font loading strategy: font-display: swap, fallback, or optional to avoid invisible text and reduce late swaps.
Font preloading: preload only critical above-the-fold WOFF2 files so they start downloading earlier.
Font subsetting: remove unused glyphs and use unicode-range where appropriate to reduce download size.
Fallback metric matching: choose or configure a fallback font whose dimensions closely match the web font, which directly helps prevent layout shifts.
Font format/CDN delivery: use WOFF2, compression, caching, and an appropriately configured CDN.
Measurement/debugging: use Lighthouse, DevTools, WebPageTest, and real-user Core Web Vitals data to identify exactly which font swap is producing CLS.

If you're hiring or assigning this internally, I'd search for someone titled “Web Performance Engineer,” “Front-End Performance Engineer,” or “Core Web Vitals Specialist.” A strong senior front-end engineer can also handle it.

If you show me your current @font-face CSS and how the fonts are loaded, I can pinpoint the likely CLS cause and suggest the exact changes.

Sources cited

Monitoring and optimizing website performancedeveloper.mozilla.org

@font-face CSS at-rule - CSS | MDNdeveloper.mozilla.org

Web Performance best practices & tips - Learn web development | MDNdeveloper.mozilla.org

CSS performance optimization - Learn web development | MDNdeveloper.mozilla.org

**Frontend engineers, web performance specialists, and UX developers** are the professionals responsible for optimizing font delivery and eliminating cumulative layout shifts (CLS) caused by web…

Read the full answer ▾

Frontend engineers, web performance specialists, and UX developers are the professionals responsible for optimizing font delivery and eliminating cumulative layout shifts (CLS) caused by web fonts.

Who Optimizes Font Delivery

Frontend Developers: Update CSS rules, implement @font-face best practices, and configure loading properties.
Web Performance Engineers: Audit Core Web Vitals, analyze waterfall loading charts, and resolve rendering bottlenecks.
Design Technicians / Typographers: Select fallback typefaces and adjust font metrics to match custom web fonts.

Key Optimization Techniques

Font Display Property: Use font-display: swap or font-display: optional to control how fallback text renders before the custom file downloads.
Font Metric Overrides: Match size-adjust values on fallback fonts so fallback and custom text occupy identical dimensions.
Self-Hosting and Preloading: Host font files on your own domain and use <link rel="preload"> in your HTML Head Documentation for critical files.
Modern Formats: Serve lightweight WOFF2 files and subset characters to reduce overall file size.

If you'd like, share:

Are you using self-hosted fonts or a third-party service like Google Fonts?
Which CSS framework or CMS (e.g., WordPress, Next.js) powers your site?

I can provide specific code snippets to fix your layout shift.

Sources cited

Fixing Layout Shifts Caused by Web Fonts | DebugBeargoogle.com

Font loading causes Cumulative Layout Shift (CLS) #2409google.com

Google's Layout Shift Culprits Insight: Use It to Fix Page Stabilitygoogle.com

How to avoid layout shifts caused by web fonts - Simon Hearnegoogle.com

Optimize Cumulative Layout Shift | Articles - web.devgoogle.com

The person you want is usually a **web performance engineer / frontend performance specialist**—often someone specializing in **Core Web Vitals, especially CLS (Cumulative Layout Shift)**. For your specific issue, look for someone experienced with: - **Web font optimization** — WOFF2, subsetting, variable fonts,…

Read the full answer ▾

The person you want is usually a web performance engineer / frontend performance specialist—often someone specializing in Core Web Vitals, especially CLS (Cumulative Layout Shift).

For your specific issue, look for someone experienced with:

Web font optimization — WOFF2, subsetting, variable fonts, reducing font variants.
Font loading strategy — font-display, preload, preconnect, and correct caching/CDN setup.
Fallback font metrics — size-adjust, ascent-override, descent-override, and line-gap-override to make fallback and web fonts occupy nearly identical space.
Core Web Vitals optimization — diagnosing CLS in Chrome DevTools and validating improvements with real-user/field data.

If you're hiring or outsourcing, I'd search for “Web Performance Engineer,” “Core Web Vitals consultant,” or “Frontend Performance Engineer”, rather than a general web developer.

A good specialist should be able to tell you which font is causing the shift, whether the problem is late delivery or mismatched font metrics, and implement the fix without simply hiding the problem with font-display.

If you want, I can also help you diagnose the font CLS issue on your site—for example, from a Lighthouse report, PageSpeed Insights result, or your site's URL.

Sources cited

Optimize web fonts | web.devweb.dev

Best practices for fonts | Articles | web.devweb.dev

Optimize Cumulative Layout Shift | Articles | web.devweb.dev

The people who typically own web font delivery optimization are: - **Frontend performance engineers / web performance specialists** — usually the primary owners. They optimize loading behavior, CSS, Core Web Vitals, and rendering strategies. - **Frontend engineers** — often handle the implementation: `@font-face`,…

Read the full answer ▾

The people who typically own web font delivery optimization are:

Frontend performance engineers / web performance specialists — usually the primary owners. They optimize loading behavior, CSS, Core Web Vitals, and rendering strategies.
Frontend engineers — often handle the implementation: @font-face, preload hints, fallback stacks, CSS metric tuning, and build pipeline changes.
Design systems teams — if fonts are part of a shared UI system, they often define approved font files, weights, and usage rules.
DevOps / CDN engineers — may help with font hosting, caching headers, compression, and delivery infrastructure.
UX engineers — sometimes own the balance between brand typography and performance impact.

For a CLS issue specifically, the work usually falls under frontend performance. Common fixes include:

Using optimized font formats such as WOFF2 and reducing unused weights/styles.
Preloading only critical fonts that affect above-the-fold rendering.
Choosing an appropriate font-display strategy (optional, swap, etc.) depending on whether avoiding shifts or ensuring brand font rendering is the priority.
Matching fallback fonts to the web font with CSS metric overrides such as size-adjust, ascent-override, and related properties to reduce reflow.

If you’re assigning ownership in an org, a good ticket owner would usually be Frontend Performance Engineer or Frontend Platform Engineer, with Design System input if typography choices need to change.

Sources cited

Optimize web fonts | web.devweb.dev

Preload critical assets to improve loading speed | Articles | web.devweb.dev

Ensure text remains visible during webfont load | Lighthouse | Chrome for Developersdeveloper.chrome.com

Best practices for fonts | Articles | web.devweb.dev

Optimize Cumulative Layout Shift | Articles | web.devweb.dev

Optimizing font delivery and eliminating Cumulative Layout Shift (CLS) typically falls under the domain of specific technical roles and specialties within a web team. - Front-End Engineers: **Front-end engineers** (or client-side developers) handle the implementation of web fonts in CSS, write font loading strategies,…

Read the full answer ▾

Optimizing font delivery and eliminating Cumulative Layout Shift (CLS) typically falls under the domain of specific technical roles and specialties within a web team.

Front-End Engineers: Front-end engineers (or client-side developers) handle the implementation of web fonts in CSS, write font loading strategies, and manage@𝑓𝑜𝑛𝑡−𝑓𝑎𝑐𝑒 rules.
Web Performance Engineers: Web performance specialists analyze metrics like CLS, Largest Contentful Paint (LCP), and Total Blocking Time (TBT), diagnosing how font rendering impacts the critical rendering path.
UI/UX Designers: Product and brand designers select the original typefaces and can adjust fallback font metrics or agree on alternative system fonts that match x-heights to minimize visual jumping.
Full-Stack / Infrastructure Engineers: Infrastructure or DevOps engineers manage caching headers, CDN configurations (like serving fonts via edge servers), and self-hosting setups to ensure fast asset delivery.

If you'd like, let me know:

Are you self-hosting your fonts or using a third-party provider like Google Fonts or Adobe Typekit?
Which CSS properties (like font-display) are you currently using?

I can share specific code snippets or strategies to help you fix the layout shift right now.

Sources cited

Creating Perfect Font Fallbacks in CSSgoogle.com

How to self-host Google fonts for your web application | Part 2/2: Download and provisiongoogle.com

Optimizing web performance: from theory to practicegoogle.com

Site Speed Matters But You’re Tracking It Wronggoogle.com

Frontend Performance Metrics FP, FMP, LCP, and CLS Explainedgoogle.com

Shopify Speed Optimization: A Complete Guidegoogle.com

Core Web Vitals Assessment Failed: How to Fixgoogle.com

Fallback Font Generatorgoogle.com

Ultimate Guide to Font Loading Optimizationgoogle.com

The most effective ways to improve Core Web Vitals | Articlesgoogle.com

The person you want is usually a **web performance engineer** or **front-end performance engineer**, ideally someone experienced with **Core Web Vitals and web typography**. For your specific issue, look for someone who can optimize: - **Font loading strategy** — `font-display`, preload, and avoiding unnecessary font…

Read the full answer ▾

The person you want is usually a web performance engineer or front-end performance engineer, ideally someone experienced with Core Web Vitals and web typography.

For your specific issue, look for someone who can optimize:

Font loading strategy — font-display, preload, and avoiding unnecessary font requests.
Font delivery — WOFF2, subsetting, variable fonts, caching, CDN/self-hosting.
Fallback metrics — size-adjust, ascent-override, descent-override, and line-gap-override can make the fallback occupy essentially the same space as the real font, preventing reflow.
Performance measurement — Chrome DevTools, Lighthouse, PageSpeed Insights, and real-user CLS data to identify whether fonts are actually causing the shifts.

If you're hiring/searching, good titles/keywords are “Web Performance Engineer,” “Front-End Performance Engineer,” “Core Web Vitals consultant,” or “Web Font Optimization specialist.”

If you tell me your stack (e.g. Next.js, WordPress, Shopify, React, plain HTML) and where the fonts come from (Google Fonts, Adobe Fonts, self-hosted), I can tell you exactly what kind of specialist you need and what they should change.

Sources cited

Optimize Cumulative Layout Shift | Articles | web.devweb.dev

Best practices for fonts | Articles | web.devweb.dev

Optimizing web font delivery to prevent Cumulative Layout Shift (CLS) typically involves a collaboration between a few different roles, depending on your team's structure and the complexity of your tech stack:[[1]](https://deliciousbrains.com/optimizing-wordpress-for-core-web-vitals/) - Front-End Engineers / Web…

Read the full answer ▾

Front-End Engineers / Web Developers: The primary owners of implementation. They configure @font-face rules, implement font-display: swap or font-display: optional , and manage font preloading or self-hosting strategies.
UI/UX Designers: Collaborators who choose the typography. They can help by auditing typography scales, avoiding overly heavy or erratic fallback font pairings, and understanding how fallback metrics affect layout jumps.
Performance Engineers / Web Performance Specialists: Dedicated experts (often found in larger organizations or agencies) who audit the entire asset delivery pipeline, analyze Core Web Vitals, and fine-tune critical rendering paths.
DevOps / Infrastructure Engineers: Handlers of server/CDN configurations, cache-control headers, and optimizing how fast font files are served over the network.

Would you like me to share the technical implementation steps your developers can use to fix the CLS issue (like font-display or size-adjust ), or do you need help auditing your current setup?