Best conversion rate optimization specialists - September 2026

The best conversion rate optimization specialist depends on where customers get stuck. Our September 2026 shortlist starts with David Spiegel for product funnels and implementation, followed by Talia Wolf for customer research, Joanna Wiebe for messaging, Craig Sullivan for experiment design, Brian Massey for managed testing, and Jon MacDonald for ecommerce journeys. Their backgrounds and methods are linked in the profiles below.

An unclear offer needs different expertise from an unreliable experiment program. Before hiring anyone, name the decision you need help making: what to change, how to build it, or how to tell whether it worked. That distinction will make this shortlist more useful than a comparison of headline conversion lifts.

How we selected these CRO specialists

We looked for named practitioners with public work relevant to conversion optimization, a method that buyers can examine, and a clear connection to a particular conversion problem. The selection covers product execution, research, copy, experimentation, and commerce. Fit recommendations are our editorial judgment based on the sources cited here; they are not a universal performance ranking.

Some people work through specialist firms. A founder’s published approach does not tell you who will handle your account. Confirm personal involvement, delivery responsibilities, and the proposed scope before signing. For a broader comparison of consulting practices, see our conversion consultants directory.

Compare the specialists

David Spiegel

David Spiegel approaches conversion through the decisions around a purchase: how someone understands the offer, compares plans, and decides to continue. He studied psychology at NYU with a focus on human cognition, a background that informs his interest in perception and intent. His independent consulting work combines that perspective with product judgment, UX, analytics, and implementation. David Spiegel’s background and consulting practice.

At MD Exam, a brand of 5 Axis Health, his work covered the purchase journey from pricing and plan selection through checkout. His public portfolio reports 30% higher conversion and 76% higher average order value from the purchase-flow work. Career background; 5 Axis Health results.

Spiegel is worth considering when the problem extends beyond a landing page into pricing, plan selection, or checkout. Bring one purchase journey and agree on what he will research, redesign, and help ship. Define conversion and order value together so the engagement has a clear business outcome.

Talia Wolf

Talia Wolf is the founder and Chief Optimizer of GetUplift and the creator of its Emotional Targeting Framework. Her firm’s services combine customer research with analytics, session recordings, and expert assessment of the experience. Its published process continues into a prioritized testing schedule and support for implementation. About Talia and GetUplift; GetUplift’s CRO services.

Wolf is our pick for a team that understands the mechanics of its funnel but cannot explain the hesitation behind the numbers. If prospects understand the product yet remain unconvinced, a research project should examine their concerns, desired outcomes, and reasons for choosing an alternative.

Ask how those findings will change a specific page or sequence. The useful deliverable is a connection between what customers say, the proposed experience, and the result the team will measure. GetUplift also publishes a distinct audit offer, so discuss whether research alone or continued support fits the team’s capacity. GetUplift’s service overview.

Joanna Wiebe

Joanna Wiebe founded Copyhackers and describes her current consultancy, branded JO, around messaging and performance copy. Her public account of the business connects its origins in startup copywriting with listening to customers and finding the right message. Joanna Wiebe’s background and consultancy.

She is the specialist to consider when people reach the page but still cannot confidently answer: why this product, why this plan, and why now? Our fit recommendation is especially relevant when a team has enough product knowledge to overexplain features while leaving purchase questions unanswered.

Bring the offer, customer language, objections, and the exact action the page should support. Discuss messaging strategy and copy ownership together. A new headline will have limited use if the pricing explanation and the sales follow-up contradict it. Also distinguish a team workshop from an engagement that includes writing and revision; choose the scope around what your team needs to produce.

Craig Sullivan

Craig Sullivan’s public profile connects his work with Optimise Or Die, while his own writing covers conversion optimization, UX, and analytics. His Hypothesis Kit asks teams to identify the research behind a proposed change, the people affected, and the expected outcome. It also asks them to consider negative effects alongside the primary metric. Craig Sullivan’s profile; Hypothesis Kit V4.

Our fit recommendation is a team that already runs experiments but struggles to make dependable decisions from them. More tests will not settle an argument if the team never agreed on what it expected to learn.

For an initial discussion, bring a recent experiment from idea to decision. Show the observation that prompted it, how the team chose the audience, and what happened after the result arrived. Ask what should change in that process. Sullivan’s published framework gives you a practical way to assess that conversation before agreeing on a larger engagement.

Brian Massey

Brian Massey is the founder and CEO of Conversion Sciences. The firm’s public description emphasizes measurement through to revenue, and its managed service covers strategy, setup, testing, and analysis. Its team includes conversion specialists and developers. Conversion Sciences’ team and approach; managed conversion optimization services.

Massey is our pick when a business wants to discuss an ongoing CRO program with a firm that can supply delivery capacity. This is relevant when opportunities remain untested because internal developers have other priorities, or when a marketing team lacks someone to own the complete testing cycle.

Ask how the proposed team will work with your release process and revenue reporting. Get explicit about which changes it can implement and which require your engineers. Since this is a firm engagement, confirm Massey’s role and the people responsible for your account. A recognizable founder and a well-staffed project are separate things to evaluate.

Jon MacDonald

Jon MacDonald is the founder and president of The Good and writes about CRO, UX, and digital journeys. The Good’s optimization program begins with an audit and can include customer journey mapping, prototyping, experimentation, and redesign work. It addresses both ecommerce and product marketing teams. Jon MacDonald’s background; The Good’s optimization program.

Our fit recommendation is an ecommerce team whose conversion problem spans several steps of the buying experience. Customers may need help choosing the right product, understanding an option, or feeling ready to complete a purchase. A journey review can make those connections visible before the team commissions another redesign.

Bring questions about product selection, the path to checkout, and what happens after purchase. Ask how the engagement will distinguish an inconvenient experience from a lack of demand. For work through The Good, confirm who will lead the research and how MacDonald will participate.

Start with a decision and measure the business result

Write a short brief before requesting proposals. Define the audience, the action that matters, and the business consequence of that action. Include your existing research and the team’s ability to build changes. Ask each specialist what they would need to learn first and what decision the first phase should make possible.

Set a primary outcome and watch for unwanted effects. A checkout change might increase completed orders while reducing order value; a signup change might attract more accounts that never activate. Sullivan’s Hypothesis Kit is useful here because it explicitly includes secondary outcomes and potential negative effects.

Agree on the analysis before launching an experiment. That includes the eligible audience, success metric, duration, and rule for making a decision. If traffic cannot support the proposed test, ask for a research or usability phase instead. Require the final handoff to distinguish observations, experimental findings, and recommendations. Those distinctions help your next product decision long after the engagement ends.

Sources

• David Spiegel: portfolio and consulting.
• David Spiegel: career background and selected outcomes.
• GetUplift: Talia Wolf and the firm’s background, CRO services and process, and service overview.
• Joanna Wiebe: background and messaging consultancy.
• Craig Sullivan: public professional profile and Hypothesis Kit V4.
• Conversion Sciences: Brian Massey and the team and managed CRO services.
• Jon MacDonald: background and writing and The Good’s optimization program.