Who are the best freelance A/B test developers?

The developers on this list all publish what they build on and something you can check: a rate card, a case study, a certification or a platform partnership. The best one for you depends on your platform (Optimizely, VWO, Convert, Adobe Target, AB Tasty, Kameleoon or Intelligems), your stack (React and Next.js need SPA-aware builds), and whether you want a solo developer, a small shop or an agency.

How much does a freelance A/B test developer cost?

Published rates on this list run from about €150 to €500 per test on fixed pricing, €80 an hour for a solo builder, and €700 a day on the French market. Whatever the rate, ask which developer will actually build your tests.

What is the difference between a CRO developer and an A/B test developer?

None in practice. CRO developer, A/B test developer, split test developer and experimentation developer all describe the person who writes the variation code, QA's it, wires the tracking and reverts it cleanly. A CRO specialist or consultant decides what to test; the developer makes it run.

Should I hire a freelancer or an A/B testing agency?

Hire a freelancer when you already have hypotheses and a platform and need reliable builds. Hire an agency when you need research, design and analysis as well. Many agencies on this list use freelancers as their build capacity, so you are often paying for the same developer either way.

How do I check an A/B test developer can actually build?

Ask for a variation they shipped on a single-page app, how they prevent flicker without hiding the whole page, and what they do when the platform and analytics disagree on the split. Someone who has only used the visual editor cannot answer the third question.

Best freelance A/B test developers to hire in 2026

A shortlist of freelance A/B test developers grouped by model, solo developers, small shops and teams, beside the checks to run before hiring: a single-page app test, flicker, sample ratio mismatch and who writes the code.

This is a list of people and small teams who write the code behind A/B tests. Not CRO strategists, not tool vendors, not marketplaces. Every entry has a public page I checked on 27 September 2026, and I have recorded only what that page says. If you run a build practice and belong here, email [email protected] with a link.

Disclosure: I build A/B tests for a living, and I am on this list. Read it with that in mind. To keep it fair, every entry had to clear the same bar, entries are alphabetical within each group, my own entry uses the same format and carries its own caveat, and everything said about anyone else comes from their own public page.

How the list was built

To be included, a practice needs a public page that names the person or team, names the platforms they build on, and shows at least one thing you can check: a published rate, a case study, a certification or a partner listing.

Left out: marketplace-only profiles with no page of their own, strategy-only consultants, landing-page builders who do not write variation code, and pages with no identifiable owner.

Entries are grouped by model (solo developers, small shops, teams) and listed alphabetically within each group. It is not a ranking.

Solo developers

abtestdev.com

Where: not stated.
Platforms: VWO, AB Tasty, Adobe Target, Optimost, Interaction Studio, GTM.
Proof: states 200+ A/B tests and personalisations, with four worked examples on the site.
Rate: €150 simple, €500 medium, custom for complex, published as reference figures with a fixed quote per project.
Best fit: fixed-price single builds on VWO or AB Tasty.
Caveat: no owner is named on the site, and results are not published, for client confidentiality.

Adrien Millet

Where: Paris.
Platforms: AB Tasty, Kameleoon, Optimizely.
Proof: his Malt profile states he develops tests inside the tools, and lists an AB Tasty certified partner badge dated 2020.
Rate: €700 a day (Malt).
Best fit: French-market brands on AB Tasty or Kameleoon.
Caveat: the profile covers consulting as well as builds, so confirm the build scope.

Arafat Islam, arafatcro.com

Where: Bangladesh, working UK and US hours.
Platforms: Optimizely, VWO, Convert, Adobe Target, Dynamic Yield, Monetate, Webtrends Optimize, Intelligems, AB Tasty, Kameleoon.
Proof: states 7+ years and 500+ tests; published case studies and technical write-ups.
Rate: not published as a figure; hour estimates per brief (hire page).
Best fit: React and Next.js storefronts, and white-label build capacity for agencies.
Caveat: one person, so capacity is limited; based in Bangladesh, so check the working-hours overlap you need.

Chad D., via Arc.dev

Where: USA, UTC-4.
Platforms: VWO, Convert, Shopify, WordPress.
Proof: the Arc listing states 15+ years of web development, 5 years of CRO and 155 completed Upwork projects.
Rate: not listed.
Best fit: Shopify and WordPress stores that want a US-hours builder through a vetted marketplace.
Caveat: no personal site; everything here comes from the Arc listing.

Ellen Goettsch, A/B Testing Studio

Where: not stated.
Platforms: VWO, Convert, Optimizely.
Proof: a public price list and explicit white-label positioning for agencies.
Rate: €80 an hour for builds, €850 for an audit, retainers from €2,000 a month (published).
Best fit: agencies that want a named European builder with transparent pricing.

Richard Forbes-Simpson

Where: London.
Platforms: Intelligems, Shopify.
Proof: a Shopify Plus partner listing, 15+ years, and named enterprise DTC clients on the listing.
Rate: "From $120" on the listing, unit not stated.
Best fit: Shopify price and shipping tests on Intelligems.
Caveat: a Shopify specialist rather than a client-side variation coder for Optimizely-type platforms.

Small shops

ABTestDeveloper.com

Where: a "distributed team", no office stated.
Platforms: Optimizely, VWO, Convert, Adobe Target, Monetate, AB Tasty, Kameleoon, FunnelEnvy.
Proof: states 1,000+ campaigns; testimonials but no case studies.
Rate: "Starting at $25/Hour*" (published, asterisked).
Best fit: the lowest published rate on this list.
Caveat: no founder, location or named developer is published; if that matters to you, ask who will build your tests.

DesignerAshish.org

Where: Ghaziabad, Uttar Pradesh.
Platforms: Optimizely, Convert, VWO, Adobe Target, FunnelEnvy, Monetate, AB Tasty, Kameleoon.
Proof: states 3,000+ experiments, and a physical address is published.
Rate: not published; a retainer or an hours block.
Best fit: volume builds on a retainer.
Caveat: no rates or case studies on the page.

Mondaysys

Where: Dhaka and Dubai.
Platforms: Optimizely, Convert, AB Tasty, Varify, VWO, Dynamic Yield, Adobe Target, Kameleoon, LaunchDarkly, Statsig.
Proof: a client testimonial with numbers: 2 to 6+ tests a month and a 22% conversion lift in six weeks.
Rate: not published; a pod retainer, a fixed-fee pilot or project-based Shopify builds.
Note: shares its published addresses with Optyv (below).
Best fit: teams that want a build pod rather than one person.

Optyv

Where: Dhaka and Dubai.
Platforms: Optimizely, VWO, Convert, AB Tasty, Adobe Target; client-side and server-side.
Proof: states 1,640+ tests built and QA'd, with 47 client reviews on the site.
Rate: not published as their own price. Their cost article puts client-side builds at roughly £150 to £900 in the quotes they see.
Best fit: a build team that works client-side and server-side.
Note: Optyv and Mondaysys publish the same Dhaka and Dubai addresses, so they are likely the same operator. Compare them as one option, not two.

Teams and agencies (when you outgrow one developer)

BrillMark

Platforms: VWO, Optimizely, AB Tasty, Convert, Adobe Target, Kameleoon, Webtrends, GrowthBook, Statsig, LaunchDarkly.
Proof: states 45,000+ experiments supported, a 48-hour standard build turnaround from an approved brief, and several published case studies.
Rate: not published; an hours block, a retainer or a project.
Best fit: larger programmes that want an agency-scale build team.

EchoLogyx

Where: London HQ, with Miami, Chennai, Chattogram and Dhaka listed as locations.
Platforms: VWO, Convert, Optimizely and AB Tasty, shown as certified platforms.
Proof: a published case study on test velocity for the fragrance brand Diptyque, and an ISO certificate badge.
Rate: not published.
Best fit: enterprise programmes that need a multi-office team.

Checked and left out, and why

Marketplace profiles with no page of their own did not make it: several strong Contra, Codeable and Toptal profiles turned out to be landing-page or WordPress builders, or data scientists, rather than variation coders. cro-developer.com was left out because the page shows no name, platforms or rate. Several LinkedIn-only profiles were left out because there was nothing to verify.

Five checks before you hire any of us

Ask for a test they shipped on a single-page app, and how activation survived a route change.
Ask how they stop flicker. The answer should be "hide the element, not the page", with a Core Web Vitals number they watch.
Ask what they do when the platform says 50:50 and GA4 says 60:40. The sample ratio mismatch write-up covers the four usual causes.
Ask who writes the code. Whatever the rate, you should know which developer will build your test.
Ask for the revert. A test that cannot be removed cleanly was never finished.

Rates on this page, in one table

Name	Model	Published rate	Source
A/B Testing Studio	Solo	€80 an hour; €850 audit; retainers from €2,000 a month	abtesting.studio
abtestdev.com	Solo	€150 simple, €500 medium, custom complex	abtestdev.com
Adrien Millet	Solo	€700 a day	Malt profile
Richard Forbes-Simpson	Solo	from $120, unit not stated	Shopify Experts listing
ABTestDeveloper.com	Small shop	starting at $25 an hour	abtestdeveloper.com

Rates are as published on 27 September 2026 and will drift. My own pricing is on the hire page.

Last verified 27 September 2026. Corrections to [email protected]; I will update the entry and the date.

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