ABOUT

FAST Score™

A simple, comparable UX performance metric for real users on real pages.

FAST Score™ is a page-level UX performance model created by J.R. Le Haye. It combines Friction, Access and Speed into a single Total score out of 100, so you can quickly see which pages are working well for users – and which need attention, combine with other webpages to measure overall journey quality.

Use FAST Score™ when you want to:
— Compare performance across a number of key pages
— Track the impact of UX or accessibility changes over time
— Prioritise where to focus design, engineering or CRO effort
— Give stakeholders a simple view of journey quality, not just traffic and revenue

Try FAST Score GPT

FRICTION

Measures how often users click on elements that do nothing.

— Metric: number of dead clicks over the last 30 days
— Output: Normalised Friction score (0–100 – fewer dead clicks = higher score)

FrictionScore = max(0, 100 - (DeadClicks / 10))

ACCESS

Measures how easy the page is to use for everyone.
‍
— Metric: Google Lighthouse accessibility score
— Criteria: ARIA tagging, screen reader support, WCAG 2.2 AA
— Output: Access score (0–100)

AccessScore = min(100, max(0, LighthouseScore))

SPEED

Measures how easy the page is to use for everyone.

— Metric: Google Lighthouse accessibility score
— Criteria: ARIA tagging, screen reader support, WCAG 2.2 AA
— Output: Access score (0–100)

SpeedScore = max(0, min(100, 140 - 20 * TimeToFirstClick))

TOTAL

Each page gets a Friction, Access and Speed score between 0 and 100.

FAST then combines them into a single weighted total:
(FrictionScore * 0.4) + (AccessScore * 0.3) + (SpeedScore * 0.3)

‍Example bands:
80–100 – Strong: the page is performing well for most users
‍60–79 – Needs improvement: targeted fixes will unlock value
‍Below 60 – Critical: users are struggling and key journeys are at risk

This allows you to benchmark templates, track releases, and share a simple number with non-design stakeholders.

GET STARTED

1. Collect your page data: dead clicks, Lighthouse accessibility, and time to first click (or dwell time × activity).

2. Add the numbers into the FAST Score template.

3. Review which pages fall into Strong, Needs Improvement or Critical.

4. Prioritise fixes starting with high-value, low-scoring pages.

Try FAST Score GPT

CONTACT

For enquiries about bringing FAST Score™ into your workflow, please contact me via the form.

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FAST Score™ was created by J-R Le Haye in 2025 as a practical way to connect UX, accessibility and behaviour into a single, human-centred performance metric. J-R is a digital design leader specialising in product design, accessibility and data-led journey optimisation.

FAST Score™ — © 2025 Jon-Ross Le Haye. All rights reserved.