Services / Performance & CRO

Shopify speed optimization & CRO.

Speed optimization and conversion rate optimization (CRO) for Shopify and Shopify Plus merchants: Core Web Vitals, Lighthouse 90+, and checkout A/B tests. We measure before we ship, instrument everything, and only call a change a win when the data agrees.

Book an audit See what's included
LCP < 1.8s
Target
INP < 200ms
Target
CLS < 0.05
Target
+184%
Avg. lift
01 — What we measure

Speed wins.
Experiments prove it.

LCP improvement −54% 3.1s → 1.4s
INP improvement −62% 360ms → 140ms
CLS score 0.02 Below 0.05 target
PageSpeed (mobile) 98 ↑ from 62
Conversion rate +184% Avg. client lift
AOV lift +22% Bundle + upsell
JS bundle size −41% 412kb → 243kb
Checkout drop-off −18% Step 2 → 3 friction
02 — How the work runs

Ninety days,
fixed scope.

How our speed engagements run, against a written performance budget both sides sign. Most stores reach 95+ mobile Lighthouse within 60 days; the third month makes the gains last.

  1. 01

    Audit & baseline

    Weeks 1–2. We pull your real-user Core Web Vitals, run Lighthouse on your top templates, list every app and set up real-user monitoring. You get a written report of the wins, in order.

  2. 02

    Images & fonts

    Weeks 3–6. Right-sized images, subset fonts and trimmed templates. This is where most of the score moves: typically 20–30 Lighthouse points.

  3. 03

    Scripts & apps

    Weeks 7–9. App scripts load only where and when they're needed, stale tags go, theme JavaScript gets trimmed: smaller score gains, a much bigger INP improvement.

  4. 04

    Make it last

    Weeks 10–12. Critical CSS, the last fixes, a Lighthouse check in CI that catches regressions, and a runbook your team keeps.

03 — Questions we hear

What people
actually ask.

What do you measure?
Core Web Vitals from real users (Chrome's CrUX data, which Google ranks on), Lighthouse in CI, and real-user monitoring that shows a change within hours. We target LCP under 1.8 s, INP under 200 ms and CLS under 0.05. When Lighthouse and CrUX disagree, CrUX wins.
Which checkout changes actually work?
In our study of 14 A/B tests on eight Shopify Plus stores, four changes won in every store that ran them: express checkout buttons above the form (+6.4% conversion), address autocomplete (+3.8%), specific trust badges (+2.9%) and a real shipping-cutoff countdown (+2.1%). Three popular changes lost, including collapsing the three-step checkout into a single scrolling form.
How do you run A/B tests?
Each test is planned before it starts: a hypothesis, a sample size and an end date. Tests run at least 14 days, nobody calls a winner early, and results are split by device, because a change can win on mobile and lose on desktop.
How soon will we see results?
Most of the speed gain lands in weeks 3–6. On conversion, the proven checkout changes go live within the first 45 days, and the tests specific to your store run until day 90.
Will you remove our apps?
Only with your sign-off. We sort every app by when it has to load: checkout, cart and search load first; reviews and recommendations wait until they scroll into view; pop-ups wait until the page is idle. Apps nobody has used in 90 days come out, with your approval.
What do we keep when the engagement ends?
A runbook: how to run the performance audit (we hand over the CI workflow), how to check a new app against the budget, and what to do when field data shows a regression. The CRO program comes with its own runbook, so your team can run it every quarter without us.
More from SevSolutions

Custom themes

Bespoke Liquid + Hydrogen builds.

Apps & integrations

Custom apps, checkout extensions, ERP/3PL pipes.

Store migrations

Zero-loss replatforms to Shopify Plus.
Further reading

Go deeper.

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