How Under Armour Targets Sub-3-Second Loads — Across 35 Global Storefronts on Fastly

Under Armour is a $5.2 billion company (FY2025 revenue, per SEC filings) running 35 global storefronts. When your ecommerce operation spans three continents, every millisecond of load time multiplies across millions of sessions. Speed isn't a vanity metric at this scale — it's revenue infrastructure.

Under Armour gets this. That's why they invested in rebuilding their entire ecommerce platform — migrating from a legacy homebuilt system to headless Salesforce Commerce Cloud, then layering on a PWA for mobile. Let's look at what they built.

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Google doesn't care about your Lighthouse score. Seriously. Lighthouse is a lab test — it's a simulation. What Google actually uses for rankings are Core Web Vitals: real data from real Chrome users visiting your real site over the last 28 days. Three numbers:

Users are 24% less likely to abandon a page when it passes all three. That's the difference between a $1M/year store and a $1.24M/year store — from metrics alone. Core Web Vitals are also a confirmed SEO ranking signal, which means slow sites lose twice: visitors leave AND Google ranks you lower.

Run a live PageSpeed test on underarmour.com right now → — you'll see their real CrUX field data.

Under Armour's ecommerce evolution is a story of three migrations. They started on a homebuilt commerce platform. As the business scaled to billions in revenue and expanded globally, that system couldn't keep up. So they made the call to move to Salesforce Commerce Cloud (formerly Demandware), partnering with Merkle for the implementation.

But SFCC alone wasn't fast enough. In 2023, Under Armour set an ambitious goal: consistently hit sub-3-second page load times. That's hard for any commerce site, but especially one running 35 storefronts across three regions with dynamic content, personalization, and localization on every page. Merkle helped move the SFCC implementation to a headless front end — decoupling the storefront from the commerce backend entirely.

What "Headless" Means (Without the Jargon)

Normal ecommerce setup: One system builds your page AND handles your payments AND manages your products. It does everything. But when millions of shoppers show up on Black Friday, "everything" becomes "nothing" because it all falls over together.

Under Armour's headless setup: SFCC ONLY handles product data, inventory, and checkout. A completely separate frontend builds the actual pages customers see. The two talk through APIs. If the frontend gets slammed with traffic, checkout keeps working. If checkout hiccups, the frontend keeps showing products. (We break down their full tech stack and security configuration in a separate report.)

The result? Per Merkle's case study, Under Armour now runs "one of the most performant ecommerce sites on the web" — a headless SFCC build spanning 35 global storefronts with sub-3-second page load targets.

Under Armour didn't stop at headless. They partnered with Astound Digital (formerly Mobify) to migrate their UK site from a responsive design to a Progressive Web App (PWA). The goal was clear: faster mobile page loads that translate directly to higher conversions and revenue.

Source: Astound Digital case study. These figures represent the UK PWA pilot results.

The 65% drop in pre-bounce rates is the headline stat. "Pre-bounce" means users who leave before the page even finishes loading. A 65% reduction means the PWA loaded fast enough that nearly two-thirds of those would-be bouncers stuck around long enough to see the page. More eyeballs on products = more conversions. Simple math.

With those results, Under Armour greenlighted a global PWA rollout. The UK was the test case. When a 16% conversion lift proves out in one market, you roll it everywhere. That's the power of investing in speed: the ROI compounds across every market, every storefront, every session.

Under Armour needed separate vendors for speed optimization, PWA development, and analytics. LeadMaxxing combines visitor tracking, lead scoring, and conversion analytics in one lightweight script — so you don't need to stack tools and tank your PageSpeed.

Under Armour runs on Fastly CDN. DNS analysis confirms their domain resolves via a CNAME to n.sni.global.fastly.net with four A records pointing to Fastly edge servers in the 151.101.x.91 range. Fastly's network uses fewer but more powerful points of presence than competitors, with instant cache purging that lets Under Armour update pricing and inventory across 35 storefronts in real time. (See our tracking and privacy audit for the complete picture of what runs on each pageview.)

Security Headers: Room for Improvement

Under Armour scores an F grade on security headers — with only 1 of 6 recommended headers present. While security headers don't directly impact page speed, they affect overall site trustworthiness and can prevent performance-degrading attacks like clickjacking and MIME-type confusion.

Under Armour's speed story proves that platform migration pays for itself. Their PWA pilot delivered a 16% conversion lift in a single market — then scaled globally. You don't need 35 storefronts or a $5B revenue base to benefit from the same principles. The biggest wins are basics: a fast CDN, image optimization, deferred third-party scripts, and monitoring real user data via Core Web Vitals. Study how they handle pricing across markets and what their email and CRM strategy looks like to understand the full picture of their ecommerce operation.

You don't need Under Armour's budget. Here's the 20% of effort that gets you 80% of their speed:

Frequently Asked Questions

How fast is Under Armour's website?

Under Armour targets sub-3-second page load times across their 35 global storefronts, per their partnership with Merkle. Their headless Salesforce Commerce Cloud architecture served via Fastly CDN delivers pages through edge-cached content globally. Their PWA migration on the UK site achieved 65% lower pre-bounce rates, indicating significantly faster perceived load times.

What ecommerce platform does Under Armour use?

Under Armour runs on Salesforce Commerce Cloud (formerly Demandware) with a headless frontend architecture. They migrated from a legacy homebuilt platform to SFCC, and Merkle subsequently helped them move to a headless front end to achieve faster page loads. The ecosystem spans 35 global storefronts across three regions.

What CDN does Under Armour use?

Under Armour uses Fastly as their CDN provider. DNS records show their domain resolves via a CNAME to n.sni.global.fastly.net with four A records pointing to Fastly edge servers (151.101.x.91 range). Fastly's edge network caches content at points of presence worldwide for low-latency delivery.

Did Under Armour's PWA migration improve conversions?

Yes. Per Astound Digital's published case study, Under Armour's PWA migration on the UK site delivered 16% higher conversion rates, 14% growth in revenue per user, and 65% lower pre-bounce rates. These results led Under Armour to greenlight a global PWA rollout across all regions.

How does Under Armour's site speed compare to competitors?

Under Armour's sub-3-second page load target positions them competitively among major athletic apparel brands. Their headless SFCC architecture with Fastly CDN provides structural advantages over brands running monolithic platforms. The PWA migration delivered measurably faster perceived load times, with 65% lower pre-bounce rates compared to their previous responsive site.

Does Under Armour use a headless commerce architecture?

Yes. Under Armour runs a headless Salesforce Commerce Cloud build, with the frontend decoupled from the commerce backend. Merkle helped implement this architecture, which spans 35 global storefronts across three regions. The headless approach allows the frontend to be optimized independently for speed while SFCC handles product data, inventory, and checkout.

What is Under Armour's security header configuration?

Under Armour scores an F grade on security headers, with only 1 of 6 recommended headers present. They implement HSTS (Strict-Transport-Security) with a max-age of 63,072,000 seconds (2 years), but are missing Content-Security-Policy, X-Frame-Options, X-Content-Type-Options, Referrer-Policy, and Permissions-Policy headers.

How many storefronts does Under Armour operate globally?

Under Armour operates 35 global storefronts across three regions, all powered by their headless Salesforce Commerce Cloud architecture. This global footprint was built through a phased migration led by Merkle, starting with key markets and expanding region by region. Each storefront is served through Fastly's CDN for localized edge caching.