> ## Documentation Index
> Fetch the complete documentation index at: https://docs.reelevant.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Real-Time Testing (RTT)

> Automatically optimise traffic distribution across content variants using multi-armed bandit logic

<img src="https://mintcdn.com/reelevant/amH2YHA9709Bju3v/images/workflows/node-real-time-testing.png?fit=max&auto=format&n=amH2YHA9709Bju3v&q=85&s=954b02e22a8eb472ebe81b4a552716fe" alt="Real-time testing node configuration panel showing content variant settings" width="1024" height="768" data-path="images/workflows/node-real-time-testing.png" />

## Overview

Real-time testing distributes traffic across content variants and automatically optimises allocation over time. It uses a **multi-armed bandit (MAB)** algorithm that balances exploration (testing underexposed variants) with exploitation (sending traffic to higher performers).

Unlike a static [Split](/advanced-guide/workflows/logic-nodes/split), real-time testing does not require a fixed split ratio. The system continuously adjusts the distribution based on observed performance.

## Configuration

The only configurable setting is the **number of variants** — select between 2 and 10. Each variant creates a separate branch in the Workflow. The node has no other configuration parameters; the optimisation logic is fully automated.

## How the Algorithm Works

1. **Initialisation** — Traffic is distributed evenly across all variants.
2. **Data collection** — The system tracks user interactions (clicks, conversions) per variant.
3. **Rebalancing** — The MAB algorithm incrementally shifts traffic toward higher-performing variants while keeping a portion of traffic on underexposed variants to detect changes.
4. **Convergence** — Over time, the best-performing variant receives the majority of traffic.

The algorithm operates continuously — there is no fixed end date or confidence threshold. If user behaviour changes (e.g., seasonal shifts), the algorithm adapts by re-exploring other variants.

## Deterministic User Assignment

Users are assigned to variants deterministically based on their identifier. The same user sees the same variant across repeated interactions within a single Workflow. This is handled identically to [Split](/advanced-guide/workflows/logic-nodes/split) node user assignment.

## When to Use RTT vs Split

| Scenario                                       | Recommended Node                                        |
| ---------------------------------------------- | ------------------------------------------------------- |
| Fixed A/B test with known split ratios         | Split                                                   |
| Automatic optimisation toward the best variant | Real-time testing                                       |
| Quick test with 2 variants                     | Either                                                  |
| 5+ variants with limited traffic               | Real-time testing (faster convergence than equal split) |

## Best Practices

* Start with 2–3 variants for faster convergence. More variants require proportionally more traffic.
* Monitor the distribution in the Workflow's statistics mode to observe how the algorithm is allocating traffic.
* Use [branch categories](/product-guide/workflows/branches) to tag RTT branches for downstream Analytics reporting.
* Do not combine multiple RTT nodes in the same branch. Use a single RTT node per decision point.