21phi turns funnel data, UX friction and merchandising gaps into a disciplined A/B testing program on Shopify, read by segment, and stays embedded with your team to act on what it finds.
21phi is a Shopify CRO agency: we run conversion rate optimization (CRO) and A/B testing for DTC brands on Shopify and Shopify Plus, as an ongoing program rather than a one-off audit. It is for brands with real traffic, a storefront they control and a team that wants decisions made on segment-level data, not averages.
CRO is the work of finding where shoppers hesitate or leave, forming a hypothesis about why, and testing a change against the current experience. An A/B test is a controlled experiment that splits traffic between variants and reads one change at a time. Together they become a steady rhythm of learning about your customers.
We are a small senior team: the people who read your funnel build the variant in the storefront code, ship it and walk you through the result at the weekly review. No hand-off between an analyst, a designer and a developer at three companies. And if traffic is too thin for a test to read, we say so on the first call.
Most CRO starts with a wish list. Ours starts with the funnel. We map the customer journey from first visit to repeat purchase, read each step from product view to completed order, and watch session replays where the numbers drop. The result is a short list of friction points ranked by how many shoppers hit them.
Only then do we write hypotheses. Each one names the surface, the change, the segment it should affect and what a win would look like. That is the testing roadmap your team can see, question and reorder.
Discipline separates a program from a guess. We test one change per variant, hold the traffic split steady across channels so paid and organic shoppers are not weighted differently, and let the test run until the segment reads are stable. We do not stop early because a chart looks good on Tuesday.
Typical surfaces, all tested on a Shopify Plus apparel storefront we run: trust block and shipping-and-returns placement on the product page, collection grid layouts (a curated system view against a filterable view-all grid), color selector UI, campaign image variants, cart upsell placement and pop-up triggers, and size selector defaults with fit hints.
Results are read by segment, never as one average. A variant that wins with returning mobile shoppers and loses with new desktop traffic is a finding, not a tie.
You get a weekly review run by us: what changed in the funnel by segment, which tests closed, what they said and what we propose next. Requests land in your own channels, where we sit alongside your founder, customer care and ads partners, and go onto a shared task board you can open.
We are honest about limits. Shopify's hosted checkout can be branded within what the platform allows and no further, some app widgets cannot be filtered the way a brief imagines, and some ideas are better deferred. We say so before the work starts.
Shopify Hydrogen is Shopify's React-based framework for building headless storefronts on top of Shopify's Storefront API. On a Hydrogen storefront we build variants directly in the storefront code, behind a controlled split, and read them in Amplitude, the product analytics platform (events, funnels, retention, session replay) 21phi uses for storefront analysis and A/B test reads. No third-party script injects changes after the page loads, so variants are fast, consistent and visible to your analytics.
The tracking layer is ours end to end: pixels in code rather than a tag-manager container, an event taxonomy (the named set of tracked storefront events and their properties) covering every interaction a test might move, and purchase events verified through to Shopify checkout. A test is only as good as its data, which is why our ecommerce analytics and CRO work are run by the same people.
An ecommerce CRO agency that hands you a report and leaves has solved half the problem. The winning variant still has to be built into the storefront, the next test queued, and the landing page for Friday's drop still has to ship. We stay for all of it.
That is the shape of every 21phi engagement: a build or a program first, then we stay on as your embedded commerce team. The agency works inside the client's channels and roadmap as the storefront, analytics and growth team, on a monthly retainer scoped per client. In that retainer we close any request from any department: integrations, broken apps, urgent fixes, campaign visuals, analytics questions, a chat widget the support team asked for. One request, one named senior person who knows your codebase. See Shopify support and maintenance.
This costs more than a body shop, and it should. A body shop bills hours against tickets and has no view of your funnel. An embedded team carries context from one test to the next, catches the broken checkout event before it poisons your data, and spends your budget where it is most likely to pay.
If you are comparing a Shopify conversion rate optimization agency with a freelancer or an in-house hire, ask three things. Who builds the variants, and do they know your storefront code? Are results read by average or by segment? What happens after the test closes?
21phi is a Shopify Partner with Shopify Plus experience, based in Toronto and working with brands across the United States and Canada. We run CRO and A/B testing on Shopify and Shopify Plus, and we do our best work where the storefront is a Hydrogen build we know line by line. Every program is scoped individually; the first step is the contact form.
A Shopify Hydrogen storefront for a men's performance apparel brand, built around product systems and run by 21phi as the embedded storefront, analytics and growth team.
Shopify Plus · Shopify Hydrogen on Remix / React Router · Oxygen edge hosting · Storefront API and Customer Account API · Shopify Markets · Shopify web pixels and ad pixels, implemented in code · Amplitude for funnels, retention and session replay · Mux for video
A Shopify CRO agency finds where shoppers hesitate or leave a Shopify store, forms hypotheses about why, and runs A/B tests to prove or disprove each one. 21phi does this as an ongoing program: UX and conversion audits, journey mapping, landing page, cart and merchandising tests, with results read by segment in Amplitude and the winner built into the storefront by the same team.
Conversion rate optimization (CRO) is the whole practice of improving the share of visitors who buy, from research and hypotheses through to shipping the change. A/B testing is one method inside it: a controlled experiment that splits traffic between variants and reads one change at a time. CRO without testing is guesswork; testing without a CRO program is a pile of unconnected experiments.
No, and any agency that does is selling something else. A disciplined A/B testing program delivers learning, not a number: some variants win, some lose, and both tell you how your customers behave. What 21phi commits to is method: one variable at a time, stable traffic splits, segment-level reads and honest weekly reporting, including the tests that did not work.
Only when there is enough traffic for a test to reach a readable result. Below that, splitting visitors between variants produces noise, not findings, and the budget is better spent on the storefront itself, analytics foundations or acquisition. 21phi says this on the first call. For stores with real volume on Shopify or Shopify Plus, the case for a program is strongest: each well-read test builds on the last.
The winning variants become the permanent storefront, the losers are removed, and the next hypotheses move up the roadmap. 21phi stays on as the embedded commerce team, working inside your channels and roadmap as the storefront, analytics and growth team, on a monthly retainer scoped individually. Every week your team sees what changed in the funnel, what it meant and which test runs next.
21phi builds and runs the analytics layer for Shopify Plus and Hydrogen storefronts, from pixels and event taxonomy to attribution, cohorts and a weekly review, and stays embedded as the team that answers the next question.
21phi designs product pages, collection grids, design systems and campaign visuals for Shopify Plus brands, builds them on Shopify Hydrogen, and stays as the team that keeps the storefront sharp after launch.
The real work starts after launch.
