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

# Comparison

> Send the same orders to multiple environments or scenarios simultaneously and compare the responses side by side.

Use the **Comparison** tab when you need to validate that a new environment configuration, API version, or vendor setup behaves identically to a known-good baseline. Instead of running the same orders manually across environments, you configure each scenario once and let FUEL send everything in parallel.

<img src="https://mintcdn.com/firepos/9UYk1f5ElnChzAeP/images/fuel/tab-comparison-en.png?fit=max&auto=format&n=9UYk1f5ElnChzAeP&q=85&s=eafc267308fae123ec9546cae8322860" alt="Comparison tab — scenario configuration and results history table" width="1920" height="945" data-path="images/fuel/tab-comparison-en.png" />

## How it works

<CardGroup cols={2}>
  <Card title="Sample groups" icon="layer-group">
    Predefined sets of orders stored in FUEL. Each group is a curated collection that covers the scenarios you want to test — different channels, processors, and product combinations.
  </Card>

  <Card title="Scenarios" icon="code-branch">
    Each scenario pairs an environment (base URL + API key) with a configuration. You define two or more scenarios to compare against each other.
  </Card>
</CardGroup>

## Running a comparison

<Steps>
  <Step title="Load a sample group">
    Select a sample group from the **Sample group** dropdown. Sample groups are managed by your team and contain a fixed set of order payloads. The orders in the group are displayed in the preview table with their channel, delivery method, and payment status.
  </Step>

  <Step title="Configure your scenarios">
    Add at least two scenarios using **Add scenario**. For each scenario, select the target environment and any configuration overrides (such as a different processor or fulfillment mode). Give each scenario a descriptive label so results are easy to read.
  </Step>

  <Step title="Send to all scenarios">
    Click **Run comparison**. FUEL sends every order in the sample group to each scenario in parallel and collects the responses.
  </Step>

  <Step title="Review results">
    The results table shows each order as a row and each scenario as a column. Each cell displays the HTTP status and FIRE order ID returned. Mismatches — where one scenario returned a different status than the others — are highlighted so you can investigate immediately.
  </Step>
</Steps>

## Reading the results

A successful comparison shows identical HTTP `201` responses and consistent order IDs across all scenarios. Common patterns to look for:

* **All green, same status** — the scenarios behave identically. Safe to promote the new configuration.
* **One scenario returns `4xx`** — the new environment has a configuration issue (missing processor, wrong API key scope, or payload mismatch).
* **Inconsistent order IDs** — expected; each scenario creates its own order in its own environment.

<Note>
  Each order in the sample group is sent with freshly generated IDs per run to avoid idempotency conflicts. You do not need to regenerate IDs manually before running a comparison.
</Note>

## Sample group management

Sample groups are created and maintained in the **Admin** section. A group typically contains 5–20 orders that represent your critical paths: at least one `POS` order, one `AGGREGATOR` order, one `delivery` and one `pickup`, and a mix of `approved` and `rejected` payment statuses.

<Tip>
  Keep sample groups small and focused. A group with 8–10 carefully chosen orders gives you faster feedback than a group of 50 redundant ones.
</Tip>

## Related tabs

* To build and test a single order before adding it to a sample group, use the [**Single order**](/en/fuel/single-order) tab.
* To replay real production orders instead of synthetic ones, use the [**Raw replay**](/en/fuel/raw-replay) tab.