1.Acceptance
By creating an account, or by using the A vs B service, you agree to these terms. If you do not agree to them, do not use the service.
If you are agreeing on behalf of a company, you confirm that you have the authority to bind that company.
You must be at least 16 to use the service.
2.The service
A vs B is an experimentation platform. You can run A/B tests, roll out feature flags, define metrics and audiences, and read results with a grade that says how much weight they carry. The service reaches your site through a browser snippet, SDKs, a command-line tool, and a browser extension.
We ship updates continuously, and the product will keep changing. If a change materially reduces what your paid subscription gets, we will give you reasonable notice before it takes effect.
3.Your account and your team
Keep your sign-in details safe. You are responsible for what happens under your account.
An organisation has members, and each member has a role that sets what they can do. An owner can invite a member, remove one, or change a role.
Your plan sets how many projects and members your organisation can have. The current limits are on the pricing page.
4.Subscriptions, billing, and usage
Paid plans are billed on the cadence you choose at checkout. Annual billing is discounted, and the discount is shown on the pricing page.
Payments are processed by Paddle, our merchant of record. Your purchase is also covered by the terms Paddle shows you at checkout.
Pro is priced by monthly visitor volume. If you go past the visitors included in your plan, automatic overage blocks are added. The size of a block and its price are on the pricing page, and the calculator there shows what a given volume costs.
Every plan includes a monthly allowance of AI copilot actions for the whole organisation, and the allowance is checked before each request.
All fees are exclusive of any applicable taxes.
Refunds and cancellation are covered by the refund policy.
If payment fails or stops, we may limit features or suspend the account until it is brought up to date.
5.Acceptable use
Do not use the service to break the law or to violate anyone else’s rights. Do not use it to distribute malware, to gain access to systems you do not own, or to take data that is not yours.
Do not run load tests or scraping workloads against the service, and do not use it in a way that degrades it for other customers.
Do not resell or sublicense the service, and do not copy or reverse engineer it except where the law gives you that right regardless of what a contract says.
6.Your content and your code, and who owns what
Everything you put into the service is yours. Your sites, your content, your variation code, your configuration, and the data collected from your own visitors all belong to you.
You give us the permission we need to host, copy, process, and serve that material, and we use it only to run the service for you. We do not sell it, and we do not use it to build products for anyone else.
The platform is ours. The software, the SDKs, the snippet, the visual editor, the design, and everything else we built belong to us. These terms let you use the platform while your account is in good standing. They do not transfer any ownership of it.
If you send us feedback or suggestions, we may use them to improve the product without owing you anything for them.
7.AI copilot
The copilot works inside the visual editor. Nothing it proposes reaches your visitors on its own: its work lands in the same reviewable change list a manual edit produces, and saving is the step that ships it.
Launching, pausing, stopping, and archiving an experiment are never done by the AI. Those are your actions.
The copilot cannot permanently delete anything a person built. If you ask it to remove your work, that work is hidden and can be brought back. Only things the copilot itself created can truly be deleted, and an ownership record on our side enforces that, not an instruction to the model.
What the copilot produces for you is yours, the same as work you did by hand.
AI output can be wrong. That is exactly why every copilot change waits for your review. Because you approve every change before it ships, you are responsible for what you approve and publish on your own site.
We do not warrant that AI output is free of errors, and copilot usage counts against the allowance described in the billing section.
8.Warranties and disclaimers
The service is provided as is and as available. To the maximum extent the law allows, we make no warranties of any kind, express or implied, including merchantability, fitness for a particular purpose, and non-infringement.
We do not promise the service will be uninterrupted, error-free, or secure, though we work to make it all three.
Experiment results and their grades are decision support. They tell you how strong your evidence is. The decisions you take on top of them, and the outcomes of those decisions, are yours.
Nothing in the service is legal, financial, or professional advice.
9.Indemnification
If a third party brings a claim against us because of your sites or apps, the content or code you put into the service, the data you collect from your own visitors, or your breach of these terms, you agree to defend us against that claim and to cover the resulting costs and damages, including reasonable legal fees.
We will tell you promptly about any such claim and reasonably cooperate with you, at your expense, in defending it.
10.Service levels
The Free and Pro plans do not include an uptime commitment, service credits, or a guaranteed support response time. We take reliability seriously, but these plans are self-serve.
Where an Enterprise agreement includes service levels, that agreement sets them, and it takes precedence over this section.
11.Suspension and termination
You can cancel at any time. Your paid plan stays active to the end of the period you already paid for, then your organisation moves to the Free plan. The money side is covered by the refund policy.
If you delete your account, we delete your data from our systems. That is a real deletion, described in the privacy policy, not a flag that hides your data from the interface.
If your account closes any other way, for example when we terminate it, you have 30 days to ask us for an export of your data. After those 30 days we are free to delete whatever remains. Deleting your account yourself skips that window, because the deletion is immediate.
If your account materially breaches these terms, or payment is seriously overdue, we may suspend it or stop serving its experiments and feature flags. For a material breach we may terminate the account: immediately where the breach cannot be put right, otherwise with reasonable notice.
What happens technically when an experiment stops being served: only running experiments are published to your site, so anything not running is not served.
When an experiment is paused, new visitors stop being put into it, and visitors already in it see your original page again. The data collected up to that point is kept.
Stopping is permanent. The experiment moves to Completed and its variation code leaves your site immediately. Results are kept.
The parts of these terms that by their nature should outlive them, including ownership, warranties, indemnification, liability, and governing law, survive the end of these terms.
12.Limitation of liability
To the maximum extent permitted by law, neither party is liable for indirect, incidental, special, consequential, or punitive damages. Aggregate liability is limited to the fees paid or payable for the service in the twelve months preceding the event giving rise to the claim. Nothing here limits liability that cannot be limited by law.
13.Governing law and jurisdiction
These terms are governed by the laws of England and Wales.
Any dispute we cannot settle between us goes exclusively to the courts of England and Wales. If you use the service as a consumer, you keep any protection of your home country’s law that cannot be taken away by contract.
Talk to us before going to court. Most problems are fixed with an email.
14.Changes to these terms, and how to reach us
We may change these terms. When we do, the date at the top changes with it, and we will give reasonable notice of any material change that affects a paid subscription.
Questions about these terms go to the legal address. Anything else goes through the contact form.