8 CRO Agencies That Actually Move the Needle for E-commerce Stores

Spending money on ads without CRO is like paying premium prices at the gas pump but driving a car with a leaky tank. You’re putting in fuel, but not all of it turns into mileage. You can keep piling on traffic, but unless you optimize your site to convert, a lot of that spend just dribbles away before it moves you forward. For your e-commerce store, Conversion Rate Optimization is the sharpest lever for growth because it turns the traffic you already have into revenue.

Here are 8 agencies with strong CRO chops. These aren’t one-trick ponies, they’re versatile partners that can help you optimize while keeping an eye on your bigger growth picture (because sometimes you need more than just a shiny checkout button).

How We Selected These Agencies

We didn’t just pull names out of a hat. To make this list, we looked at agencies with proven chops in e-comm optimization and beyond. We dug through public case studies, client reviews, and industry chatter to separate hype from reality. Each agency here treats CRO as a serious discipline, not a side hustle, and has worked with recognizable brands or delivered tangible lifts you’d want for your store.

CRO is a central strength, but not their only service
Proven record of measurable lifts in e-commerce
Transparent engagement models like performance-based, retainer, or project
Tech stack fluency with Shopify, WooCommerce, Magento, and GA4
Client proof through testimonials, case studies, or guarantees

Ranking Criteria

Before you dive into the list, here’s what mattered most when weighing agencies. These criteria keep the focus on real, measurable results and make sure any partner you choose can actually help your e-comm brand grow sustainably.

Results: Documented conversion and revenue lifts
E-comm expertise: Shopify and DTC brand experience
Engagement model: Performance-based, retainer, or project
Technology: Compatibility with e-commerce stacks
Client satisfaction: Reviews, case studies, and public proof

Summary Table

Before you dig into the agency profiles, here’s a quick side‑by‑side look. This table is for when you want the highlights at a glance before committing to the full story.

Rank	Agency	Avg Results	Strengths	Pricing Model	Focus
1	Spiralyze	38% lift in 90d	Predictive engine, full-service	Performance-based	E-commerce, SaaS
2	ConversionTeam	30% lift promise	Hands-on, custom tooling	Guarantee-based	E-commerce
3	Rocket CRO Lab	Varies	CRO + growth marketing	Retainer	E-commerce, SaaS
4	Conversion.com	Varies	Data-heavy, enterprise focus	Retainer	Mid/Large brands
5	AWA Digital	Varies	A/B test velocity, reputation	Retainer	E-commerce
6	Conversion Rate Store	Performance-tied	CRO plus funnel growth	Performance-based	E-commerce
7	SplitBase	Varies	Shopify & DTC, CRO + strategy	Boutique model	E-commerce
8	Wpromote	Varies	CRO as part of full-service	Retainer	E-commerce, DTC

Agency Profiles

This is where you get into the good stuff. Below you’ll find a closer look at each agency, what makes them unique, and why they might be the right pick for you.

1. Spiralyze: Predictive CRO With Guaranteed Wins

Spiralyze isn’t just another CRO shop. They’ve built a predictive engine scraping 78,000+ A/B test patterns to know what works before testing. That means you get high-probability wins faster. They also handle everything in-house: design, copy, dev, QA, analytics, project management. (No vendor juggling for you.)

On average, clients see a 38% lift in 90 days, with highlights like ADT doubling lead conversions, Biz2Credit gaining 84% more conversions, and a Fortune 500 healthcare client generating $54M in incremental revenue. If you’re running Shopify, their program even guarantees a 15% sales lift in 90 days or you don’t pay. Bold!

2. ConversionTeam: Transparent Testing and Tools

ConversionTeam built its reputation on structured testing and custom CRO tech that keeps everything disciplined and efficient. They focus on transparency: every experiment comes with clear reports and ROI snapshots, so you always know where you stand.

Brands like GymShark and Daniel Wellington have leaned on ConversionTeam to boost conversions and engagement. If you’re a marketer looking for a partner who’s both methodical and hands-on, this could be your play.

3. Rocket CRO Lab: CRO Meets Growth Marketing

Rocket CRO Lab is where CRO and growth marketing collide. They use behavioral research and experimentation to uncover objections, then validate with quantitative testing. But they don’t stop there: they also weave in acquisition insights, helping you optimize not just clicks but the entire customer journey.

They’ve supported fashion DTC brands and SaaS firms, reducing bounce rates by 25% and raising order values by 18%. If you’re curious about blending psychology with data science, Rocket CRO Lab makes it work.

4. Conversion.com: Data-Heavy, Enterprise-Friendly

Conversion.com (formerly WiderFunnel UK) is famous for large-scale, data-driven experimentation. Enterprise brands love their rigorous analytics and statistically validated results. They thrive on complexity, making them a match if your e-comm store gets a ton of traffic and every percentage point matters.

Clients like Domino’s Pizza, Canon, and BMW have seen millions in added revenue from their programs. If you’re a mid-to-large retailer who wants CRO proof you can show the board, these are your folks!!

5. AWA Digital: Reputation and Test Velocity

AWA Digital is all about speed and precision. With thousands of A/B tests under their belt, they know how to keep momentum without sacrificing quality. Their research phase is particularly strong, combining heuristics, analytics, and user testing before experiments go live.

They’ve helped Canon lift sales by 19% and Interflora increase conversions by 22%. If you want a CRO partner who can give your e-commerce brand a steady flow of insights and wins, AWA Digital is a safe bet.

6. Conversion Rate Store: No Win, No Fee

Conversion Rate Store works on a performance-based model, charging only when results happen. This “skin in the game” approach is appealing if you’ve been burned by vague promises before. Their bread and butter: funnel audits, test design, and execution.

Results include a 21% conversion lift for an electronics retailer and a 17% boost in AOV for a fashion store. Beyond CRO, they’ll also advise you on retention and funnel growth, making them more versatile than their pricing model suggests.

7. SplitBase: Shopify & DTC CRO Plus Strategy

SplitBase is a boutique firm laser-focused on Shopify and DTC brands. They’re known for mixing qualitative research (heatmaps, surveys, customer interviews) with quantitative funnel analysis. This means you get tests that not only convert but also strengthen customer loyalty.

Wins include Dr. Squatch boosting subscription signups by 28% and Kettle & Fire lowering cart abandonment by 15%. If you want a partner who can optimize while also advising on positioning, SplitBase brings both.

8. Wpromote: CRO as Part of a Bigger Growth Engine

Wpromote is a full-service digital agency that treats CRO as part of the bigger growth play. They integrate optimization with acquisition channels like SEO, paid search, and social, so you make the most of every traffic dollar.

They’ve worked with brands like Forever 21, TransUnion, and Zenni Optical, tightening conversion funnels while scaling acquisition. If you want CRO baked right into your broader growth strategy, Wpromote is your match.

How to Pick the Right CRO Partner

Okay, so you’ve seen the names and the numbers. But how do you actually choose the right partner for your e-comm brand? Here are some practical tips to help you spot the perfect fit.

Match platform expertise: Make sure they know Shopify, WooCommerce, or your setup
Check pricing models: Performance-based may suit you, retainers others
Ask about transparency: What does their testing cycle look like and how do they report?
Think culture fit: Your CRO partner should feel like part of your crew, not just a vendor

Final Word

The right CRO partner won’t just tweak your pages, they’ll unlock hidden gems that will lead to revenue. With the agencies above, you can squeeze more out of every visitor. The real question: who are you going to test first?