By Mehdi HassanHow much does a CRO agency charge per month?
A CRO agency typically charges between about $2,000 and $35,000 per month for an ongoing retainer, based on the range of quotes our research collected. Where a given agency lands depends on how much research it does, how many experiments it runs and whether its team designs and builds the changes or only recommends them.
The headline number hides the question that matters most for startups: who actually ships the work? A lower retainer that produces test plans your engineers must build can cost more in total than a higher one that delivers live pages. This guide breaks down the pricing models, the cost drivers and the real total cost. For how CRO works end to end, start with our conversion rate optimization guide.
What CRO agency pricing models are there?
CRO agencies use four main pricing models: a monthly retainer, a per-test or per-sprint fee, a one-off audit followed by a retainer, and performance-based pricing, with hourly billing for small tasks. Most established agencies default to retainers because CRO is ongoing work.
Model | How it works | Good for | Watch out for |
|---|---|---|---|
Monthly retainer | Fixed monthly fee for an agreed scope of research, tests and reporting | Steady, ongoing optimization | Vague scope that turns into reports, not changes |
Per test or per sprint | Priced per experiment or per block of work | Teams that want to start small | Paying for tests that can't reach significance |
Audit, then retainer | Paid audit up front, ongoing program after | Testing the fit before committing | An audit designed mainly to sell the retainer |
Performance-based | Fee tied partly to measured conversion lift | Large sites with clean, stable tracking | Disputes over attribution and what caused the lift |
Hourly | Billed by time spent | Small, ad hoc tasks | Unpredictable bills and little incentive to be efficient |
The same models show up across web agencies generally; our comparison of Webflow agency pricing models covers fixed, hourly, retainer and per-module pricing in more depth.
What drives CRO agency cost?
CRO agency cost is driven by traffic, test volume, research depth and whether design and development are in-house. Of those, the build question changes the total cost the most.
- Traffic and test volume. More traffic supports more tests, and agencies price for the throughput. A low-traffic site paying for high test volume is paying for tests that can't produce reliable answers.
- Research depth. Retainers that include regular surveys, interviews and user tests cost more, and usually produce better hypotheses. See conversion research methods.
- Design and development. Some agencies design and code every variant; others hand specs to your team. The second is cheaper on the invoice and more expensive in practice.
- Analytics and tracking work. If tracking needs rebuilding, expect setup fees. Our guide to landing page conversion tracking shows what that involves.
- Seniority and specialization. Senior strategists and statisticians cost more and tend to run fewer, better tests.
- Number of properties. Multiple products, regions or languages multiply the work.
How does a CRO-only agency compare with a design and dev retainer?
A CRO-only agency is strongest at experimentation rigor; a design and development retainer is strongest at shipping meaningful changes quickly. Which one fits depends on whether your bottleneck is knowing what to change or getting it built.
CRO-only agency | Design and dev retainer | |
|---|---|---|
Core strength | Test planning, statistics, analytics | Copy, design and code in one team |
Who builds variants | Often your developers, sometimes the agency | The retainer team |
Speed from idea to live | Depends on your dev queue | Usually faster, no handoff |
Size of changes | Often many smaller tests | Fewer, bigger research-led changes |
Best traffic fit | High, steady traffic | Low to moderate traffic, or any site needing better pages |
Main risk | Insights that never ship | Less statistical rigor on huge test programs |
For most seed to Series B startups, the bottleneck is building, not testing. The research we rely on puts the requirement for a valid A/B test at roughly 15,000 to 20,000 visitors per variant to detect a 15% lift from a 2% baseline, which many startup pages can't reach. For them, a team that can research, rewrite, redesign and ship a page is worth more than a testing calendar. CRO for low-traffic sites explains that approach.
For example, suppose two retainers at similar prices
Hypothetical example: a Series A company compares two monthly options. The first is a CRO-only agency that delivers research, test plans and analysis; its variants are built by the company's own front-end engineer, who is shared with the product team. In a typical month, one or two planned tests wait for engineering.
The second is a design and development retainer that rewrites and redesigns one key page a month and ships it, measuring before and after. Fewer formal tests, but each change goes live.
For this company, with modest traffic and a busy engineer, the second option delivers more. A company with large traffic and a dedicated growth engineering team might choose the first. This example is illustrative.
What does Designify's retainer include, and who is it not for?
Our monthly retainer is $6,000 a month, fixed. It gives you an ongoing design and development team that writes, designs and builds in one place, joins customer calls when it helps, and doesn't track hours.
- Designify monthly retainer: ongoing design and development
- $6,000/mo
- Typical range of CRO retainer quotes in our research
- $2k–$35k/mo
- Designify trial week before committing
- $1,000
It's a good fit if your site needs better pages and you want insights shipped without a handoff: rewriting heroes, redesigning pricing, building new landing pages for campaigns, improving the demo flow. It's not a dedicated experimentation lab. If you have very high traffic and want a program running many parallel tests with deep statistical analysis, a specialist CRO agency is likely the better choice. For a one-off project instead of a retainer, see what a landing page costs or what a CRO audit costs.
What should you ask a CRO agency before signing?
Ask a CRO agency how it decides what to test, who builds the changes and how it measures results on your traffic. Good agencies answer these specifically; weak ones answer with case-study percentages.
- How many tests can our traffic support per month, and how did you calculate it?
- Who writes the copy, designs the variants and codes them?
- What research do you run before proposing a test?
- How do you handle tests that don't reach significance?
- What does a month's deliverable look like in practice?
- Who owns the test code and designs if we stop working together?
- What's the minimum term, and what's the notice period?
Ask also what the first month includes. Many retainers start with an audit, and our CRO audit guide shows what a good one covers. Ongoing engagements are described week by week in our guide to landing page optimization services, which is a useful benchmark when you read proposals.
Which CRO pricing option should you choose?
Choose based on your traffic and your build capacity. High traffic plus spare engineering suits a CRO-only retainer; modest traffic or a busy engineering team suits a retainer that designs and builds the changes itself.
