# A/B testing

Sends the contact along one of the outgoing connections, chosen at random. This is how you compare two versions of a message or an offer: some people get one version, some get the other.

![Settings panel of the "A/B testing" block](https://support.watbot.org/_media/en/01-chatbots/03-blocks/02-logic/_images/ab-test.webp?v=1791781230)

## Settings

In the "Links" section, a new block has two connections — "A" and "B".

- **Connection name** — the label on the scheme. The contact does not see it.
- **"Weight"** — a slider from 0 to 1. The greater the weight, the more often the connection is chosen.
- **"Sampling probability"** — the share of contacts that will follow the connection. It is calculated automatically: the connection's weight divided by the sum of the weights of all connections.
- **"Add link"** — adds one more version. A block can have up to 10 connections in total.

## Outputs

One output per connection. The block has no "Continue" output.

## Good to know

- A connection with a weight of 0 is never chosen.
- The choice is made anew on every pass through the block. A contact who gets into the block a second time may receive a different version.
- If the chosen connection leads nowhere, the contact stays where they are.

> [!TIP]
> Change one thing between the versions — the headline, the price or the picture. If the branches differ in everything at once, you will not be able to tell what exactly worked better.