Compose

Compose is a web-based tool for planning and running conversion experiments. It suits small and mid-sized businesses, agencies, and in-house CRO teams that want to organize testing alongside execution. Its pay-as-you-go model avoids a fixed experimentation fee, though usage still carries a per-user charge.

Overview

Compose brings experiment planning, testing, and reporting into one web product. Teams can organize ideas in a collaborative hypothesis backlog, prioritize them with PIE, and map work on an experimentation roadmap. That combination is more useful to teams building a repeatable CRO process than to those seeking only a test-launch tool.

Compose supports client-side web experimentation and says it uses AWS Lambda@Edge for high-speed, flicker-free testing. It does not offer server-side testing, a meaningful limitation for teams whose experiments need to run on the server.

Key features

Experiments include A/B/n and split URL tests, with custom goals, audiences, triggers, and traffic allocation. A visual editor and audience targeting give teams ways to shape tests around particular conversion questions. Shopify users can also run no-code split-theme and split-template experiments through Shopify’s editor, making Compose a more natural fit for storefront iteration than for testing beyond the web.

Real-time reports and frequentist statistical calculations help teams assess results after launch. GA4 and BigQuery integrations connect Compose with those analytics tools. Compose says experiments, variations, collaborators, and projects are unlimited; that removes stated caps on those areas, although usage is still billed according to monthly tested users.

AI hypothesis generation is marked as coming soon, so it should not be treated as a current planning capability.

Pricing

The Early Adopter Plan is free, with usage billed at $0.0012 / Monthly Tested Users (MTU). There is no minimum tested-user requirement, and the plan includes unlimited experiments, variants, collaborators, and projects. Charges begin when an experiment is initiated; usage for each month is billed on the first of the following month. This model can suit teams that want to start without a fixed monthly experimentation charge, but costs rise with tested-user volume.

Compose has no traditional free trial. Users can explore the platform free until launching their first experiment, at which point billing begins. That gives teams a chance to explore before committing usage, but it is not a free testing tier.

Two optional technical sessions are available: the Half-day with Compose team costs $400, paid once, a one-time fee paid up front for a half-day video session; the Full-day with Compose team costs $800, paid once, also paid up front, for a full-day video session. These are best suited to teams that want focused technical time rather than ongoing included assistance.

The Advanced Support Add-on has custom pricing: it is a subscription with a dedicated success manager, up to one hour of monthly meeting time, chat support, and continuous data storage. Standard support includes a complimentary one-hour onboarding session, email support, and a help center with tutorial videos; advanced support and technical sessions cost extra.

Platforms

Compose supports the web. Its Shopify integration works through Shopify’s editor, but the product does not provide server-side testing.

Who it's for

Compose is a good fit for small and mid-sized businesses, agencies, and internal CRO teams that need a shared way to plan experiments and run client-side web tests. Shopify teams may value the no-code theme and template testing in particular. It is a poor fit for teams that need server-side experiments or testing outside the web.

Pros and cons

• Structured CRO planning: A shared hypothesis backlog, PIE prioritization, and roadmap help teams coordinate a testing program.
• Flexible web tests: A/B/n and split URL options, targeting controls, and Shopify theme and template tests cover several common client-side workflows.
• Usage-based entry: No minimum tested users and free exploration before the first launch reduce the barrier to getting started, while usage billing means costs depend on tested-user volume.
• No server-side testing: Teams that need experiments executed on the server will need another product.
• Some support is paid: Advanced support and dedicated technical sessions add cost beyond standard onboarding, email, and help-center resources.

Alternatives

For feature-flag and experimentation needs across more platforms, Confidence by Spotify has Android, iOS, API, and web support, plus a free plan with 75,000 credits per month and unlimited seats. Bucketeer is worth considering when open-source, self-hosted software and no per-seat pricing matter more than Compose’s managed web testing.

GrowthBook offers a self-hosted free plan with one project, unlimited feature flags and experiments, and unlimited traffic; it may suit teams that prefer self-hosting. Statsig has a free Developer plan with 2M events per month, unlimited seats, and one-year analytics retention, making it an option for teams seeking event-based analytics alongside experimentation.

Marpipe is a free-plan alternative for teams focused on catalog creative and feed management. Amplitude offers a free plan with 2M events per month and 10,000 monthly session replays, which may suit teams whose priority is product analytics rather than Compose’s CRO planning workflow.

Optimizely Experimentation offers free feature flags and one experiment at a time, a narrower free starting point for teams evaluating experimentation. AB Tasty is another paid experimentation option with a free trial. For category comparisons, see Experimentation Platforms and A/B Testing Tools.

Verdict

Choose Compose if your team wants a shared CRO planning workflow, flexible client-side web tests, and usage-based billing without a minimum tested-user threshold. Its Shopify workflow and structured planning tools are its clearest advantages. Look elsewhere if server-side testing is essential, or if your team needs a fixed-price plan rather than charges tied to monthly tested users.