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A/B testing and feature flags

Serious statistics.Made effortless.

Free forever, up to 10,000 visitors a month. No card. No trial.

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  • A trust grade on every result. Every test is scored A to F on how it was run, so you know which wins are safe to ship.

  • Three engines, side by side. Bayesian, Frequentist and Sequential read the same data and tell you plainly whether they agree.

  • An AI copilot that builds for you. Describe the change you want. The copilot builds it on your real page, and nothing goes live until you approve it.

01: The difference

Know which wins are real.

Anyone can show you a lift. We grade every result, A to F, on how the test was run, and the grade caps itself when the data looks too good to be true. So before you spend money acting on a result, you know how much weight it can carry.

  • The plan locks at launch. What you are measuring, and what counts as a win, is settled before traffic starts. Changing it afterwards is recorded and scored, so nobody can move the goalposts.

  • Three engines, one dataset. Bayesian, Frequentist and Sequential read the same numbers side by side. When they agree, you can stop arguing and ship.

  • It counts your peeks. Everyone checks results early. Every look is recorded, and peeking is one of the five things the grade scores.

  • 3

    Statistics engines, each on published, cited methods.

  • A to F

    A trust grade on every result, scored out of 100.

  • 29.8 KB

    The smallest snippet build, gzipped. Your site gets the build that carries only what your project uses, and a gate stops any of them passing 37.

  • Unlimited

    Seats and projects, on every plan including Free.

  • 0

    Sales calls required. Every price is public and self-serve.

  • 7 days

    Money back on your first payment, no reason needed.

See how a result is read, end to end
02: The copilot

Just describe it. Then review every change.

Tell the AI copilot what to change, in plain English. It edits your real page, using your colours, your type, and your spacing.

Every change it proposes lands in a list you review. Keep, adjust, or undo each one before anything goes live.

Prefer to build it yourself? Point and click in the visual editor, or write TypeScript with linting strict enough to block a broken save.

See the copilot, step by step
03: Feature flags

Feature flags, with the same discipline.

A flag can hold on or off, a piece of text, a number, or structured settings. Four kinds of value, each with its own key per environment.

Turn a flag up, down, or off from the dashboard. Nothing redeploys.

Every rollout is measured by the same three engines that judge your experiments, and every change lands in the audit log with a name on it.

See how shipping works
04: Everything else

Everything else
you get.

One script tag, sized to your project.

From 29.8 KB over the wire, measured from the real builds rather than estimated. Your site is served the build that carries only the parts your project actually uses, worked out again every time you publish. It decides which variation a visitor gets in their own browser, with no round trip to us, and the same visitor gets the same one every time.

html
1<!-- In your <head>, as high as you can put it -->
2<script src="//cdn.avsb.cloud/snippet.js"
3        data-avsb="YOUR_SNIPPET_KEY"></script>
4

5<!-- Anywhere in your own code -->
6window.avsb.track.event('purchase', { revenue: 49 });

And it is not allowed to grow.

The size is a build gate, not a promise. Each of the 4 builds has its own limit, and a change that pushes one past it fails our build instead of reaching your visitors. The numbers cannot quietly grow.

Metrics, defined once.

4 kinds of metric: click, pageview, custom event, purchase. Purchase is built for commerce and needs no hand-instrumenting. Define a metric once and reuse it across one project or across the whole organization, so two teams cannot quietly measure the same thing two different ways.

Metric library
Seven rows of a project's metric library, each naming a metric that has already been defined and the kind of behaviour it counts, a pageview, a click or a custom event.

Audiences, nested as deep as you need.

13 built-in targeting conditions, combined with and and or, nested to whatever depth the question actually has. Save an audience once and reuse it across experiments and flags.

Audience builder

One audience

AND
  • LocationUnited States or Canada
  • OR
    • Devicemobile
    • New vs returningreturning

9 analytics integrations.

Send exposures and conversions to the tools your team already reports in, or to a webhook of your own for anything not on the list. Your existing dashboards keep working; they just gain a variation column.

Integrations
Two analytics destinations in a project's integration settings: the first with the identifier it sends to already filled in, and the second named underneath it, listed and ready to connect.

15 packages, installable today.

React, Next.js, Vue, Svelte, Solid, Angular and React Native each get a real package rather than a snippet of glue code, alongside the browser, the server and the edge.

bash
1npm i @avsbhq/react

Work on a variation locally.

Clone an experiment’s code onto your machine, edit it in your own editor, push it back, and pull the latest down. It checks for changes made while you were away and tells you before it overwrites anything.

bash
1avsb clone <projectId>
2avsb dev
3avsb push

A documented REST API.

Experiments, flags, metrics, audiences, segments, members, roles and webhooks, all reachable from your own code, with reference documentation for every one of them.

Read the developer reference
05: The tour

See how it works for yourself.

Seven short steps take an idea from hypothesis to verdict, with the real product on screen at every step.

Take the tour
  1. 01ExpectSay what you expect. The plan seals at launch.
  2. 02BuildPoint and click, write code, or ask the copilot.
  3. 03TargetChoose who sees it, and how traffic splits.
  4. 04WaitKnow the cost in days before you start.
  5. 05ReadThree engines, one verdict, and a trust grade.
  6. 06ShipRoll out behind a flag, with names on every change.
  7. 07RepeatShip what wins. Test the next idea.
The revenue readout of a real result: a row for the control and a row for the challenger, each with its average per visitor and the range it is trusted within, and the lift printed beside the winning row.
A real result, read in full: every arm, its interval, and the lift between them. Step 05 shows you how.
06: Pricing

A plan for every
stage of growth.

Free is a real plan, not a trial: 10,000 visitors a month and everything except the AI tools. Past that you pay per 1,000 visitors, from $3.00 and falling as you grow. Every plan has unlimited people and projects.

  • Free

    Free forever

    Everything you need to run your first experiments.

    $0a month

    Covers 10,000 visitors a month

    No card required.

    • A/B and multi-variant experiments
    • Feature flags (boolean, text, number, JSON)
    • All three stats engines: Bayesian, Frequentist, Sequential
    • Visual editor and browser extension
    • Browser snippet, browser and server SDKs, and the CLI
    • All 9 analytics integrations
    • Commerce experiments and revenue metrics
    • Custom roles with granular permissions
    • Unlimited people and projects
    • Data history: 90 days
    • Community support

    The AI copilot and AI assistant are the one thing Free leaves out. Add billing details to switch them on.

    Get started free

  • Usage

    Most popular

    For sites testing past the free 10,000 visitors a month.

    $3.00per 1,000 visitors

    Per 1,000 visitors, falling as you grow

    10,001 to 100,000$3.00

    100,001 to 500,000$2.50

    Above 500,000$2.00

    After your free 10,000 each month. Before tax, in US dollars.

    Everything in Free, plus

    • AI copilot in the visual editor
    • AI assistant in the dashboard
    • $0.15 per AI action
    • An optional monthly spend limit
    • Data history: 1 year
    • Standard support

    Billed on the 1st for the month before, never in advance. A month under $1 carries into the next.

    Get started free

  • Enterprise

    For agencies and high-traffic teams with custom needs.

    Custom

    Above 2,000,000 visitors a month

    Priced on your volume.

    Everything in Usage, plus

    • A price agreed for your volume
    • Pay by invoice instead of card
    • Data history: 2 years
    • Terms agreed per contract

    Tell us your traffic and what your team needs. We price it with you, and there is no minimum term.

    Talk to sales
See full pricing

Stop debating.
Start measuring.

The free plan is a real plan, not a trial, and it runs the same 3 statistics engines as the paid ones.

Start freeBook a demo