A conversion rate optimisation agency researches why visitors don't buy or enquire, then runs A/B tests to prove which changes increase sales.
In the UK, look for an agency that publishes real test results, including losses, and reports revenue per visitor rather than only conversion rate.
Every agency on this page has results in the LiftArchive database, so you can check their work before you book a call.
CRO agencies in the UK
We list practitioners who have shared A/B test results with us and whose UK base we could confirm on their own site or in public company records.
We describe only the services listed on their websites, as of November 2026. We have not audited their client work, and this is not a ranking. Oliver Kenyon is our featured practitioner.
Oliver Kenyon, Conversionwise (featured)
Oliver Kenyon co-founded Conversionwise and has 13 years in ecommerce CRO.
The Conversionwise contact page gives a headquarters at Engine Shed in Bristol and an address at 103 Farringdon Road in London.
The Conversionwise site lists ongoing CRO testing, landing page and funnel builds, full website redesigns, Shopify development, post-click audits and strategy workshops.
It says it has worked with 4,000+ brands since 2013.
Oliver Kenyon has 100 results in our archive, and some are in pounds.
A full theme test of the homepage, collections, menu and subscriptions for skincare brand BLD BRO was worth +£281,417 in annual revenue.
Their team also tested a mega menu with category descriptions and a testimonial instead of product images for +$151,192/month.
They also removed a live chat feature that was costing revenue and recovered about $28,000/month.
Blend Commerce
Blend Commerce is a Shopify CRO agency trading as Blend Commerce Ltd. Its about page lists wins at the UK eCommerce Awards 2025 and the UK Agency Awards 2025, and its registered office is in London according to public company records.
The Blend Commerce site lists CRO insights and roadmapping, CRO implementation, CRO redesigns and A/B testing, for brands in the UK, Europe, North America, the Middle East and Australia.
Blend Commerce has 150 tests on LiftArchive, which you can browse on the Blend Commerce practitioner page.
For a sports nutrition brand, adding brand value props below Add to Cart gave +149.71% conversion in the UK.
The team also publishes losses: showing express checkout buttons instead of payment icons on a travel brand's product page cut mobile conversion by 14%.
Other UK work in the database
Other agencies are credited with tests on well-known UK brands.
We haven't confirmed their locations or services, so treat these as starting points for your own research:
- Journey Further tested a dedicated PPC landing page against the product page for High Street TV's Yawn bed: +32.62% purchases.
- High Position added a Trustpilot review widget under Add to Basket at Express Watches: +58.29% purchases.
- Practicology put a shirt finder on the Thomas Pink homepage and removed a content section: +12.18% sales.
- Good Growth tested an auto-scroll to recommendations after add to basket at Pets at Home: +1.2% AOV.
- Worship Digital added a USP bar under the homepage header for Corgi HomePlan: +30.9% conversions.
@oliverkenyon
Blend CommerceBlend CommerceThe Pets at Home result is a useful reminder: a 1.2% lift sounds small, but on a large retailer it can be worth more than a big percentage on a small store.
Ask any agency what a typical win is worth in pounds, not just in percent.
Search the full test database for results on your page type.
CRO agencies in London
Of the agencies above, Conversionwise lists a London address on its contact page, and Blend Commerce's registered office is in London.
A registered office is not always where the team works, so ask where your strategist and developer are based if meeting in person matters to you.
For most CRO work, location matters less than you might expect.
Research, test builds and reporting happen in the testing tool and on calls, and the Conversionwise contact page describes three offices.
What a UK or London agency does give you is fewer time-zone issues, contracts and invoices in pounds, and familiarity with UK shoppers and UK rules.
UK cookie rules and testing
Most testing tools store a cookie or similar identifier so a visitor keeps seeing the same version.
The Data (Use and Access) Act 2025 changed the UK cookie rules (PECR), and Schedule 12 adds consent exceptions for collecting statistics to improve a website and for enhancing a site's appearance or functionality.
Each exception applies only when that is the sole purpose, users get clear information, and they have a free, simple way to object.
Whether a given testing setup qualifies depends on how the tool uses the data, so ask the agency how it handles consent and take legal advice if you are unsure.
Consent design also affects revenue. Blend Commerce replaced a consent wall with a non-blocking cookie banner and saw +32% conversion.
How to choose between them
Ask every agency the same questions:
- Can I see your losing tests? Agencies that run real tests have plenty. Both featured agencies above publish theirs.
- What metric do you report? Revenue per visitor shows whether a change made money. Conversion rate alone can hide a drop in order value.
- Do we have enough traffic? A good agency checks this before signing and says so if you need an audit instead of a testing retainer.
- Who does the work? Ask who will run research, design and development, and where they are based.
- What does it cost? Get a written scope and compare it with our CRO pricing guide.
| Agency | UK base (per own site or records) | Listed services | Tests on LiftArchive |
|---|---|---|---|
| Conversionwise (Oliver Kenyon) | Bristol HQ; London address | CRO testing, landing pages and funnels, redesigns, Shopify development, audits, workshops | 100 |
| Blend Commerce | Registered office in London | CRO roadmapping, implementation, redesigns, A/B testing | 150 |
For the full checklist, read how to choose a CRO agency.
If you want one senior person rather than a team, see our CRO consultants, or browse every practitioner in the experts directory.