---
updatedAt: 2026-02-12T13:35:59.000Z
agentTools:
  projectIndex: https://docs.emergetools.com/llms.txt
---

# What is being measured?

Emerge's performance testing allows customization of both the *scenario* (what UI test is ran) and the *measure* (what critical section within that scenario is being measured).

This table summarizes what is measured in common situations.

| Test annotation                           | Measure name                                                                                                    | Description                                                                                                                                                                                                                                             |
| :---------------------------------------- | :-------------------------------------------------------------------------------------------------------------- | :------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| *\[No test]*                              | [Time to initial display](https://docs.emergetools.com/docs/android-startup-performance-testing-1#measurements) | By default if no specific test class is found, Emerge will measure app startup recording time to initial display.                                                                                                                                       |
| `@EmergeStartupTest`                      | [Time to initial display](https://docs.emergetools.com/docs/android-startup-performance-testing-1#measurements) | You can override the default startup UI test with a custom startup scenario. This allows testing multiple entry points for example. [See more](https://docs.emergetools.com/docs/android-startup-performance-testing-1#custom-startup-scenarios) .      |
| `@EmergeTest()`                           | Duration of the test method                                                                                     | When defining a custom perf test, the default measure is the duration of the test.                                                                                                                                                                      |
| `@EmergeTest(spans = ["my_custom_span"])` | Duration of the `my_custom_span` span                                                                           | By explicitly setting a span to measure, Emerge can measure smaller critical section(s) in the app within the test duration. [See more](https://docs.emergetools.com/docs/android-custom-flow-performance-testing#performance-testing-specific-spans) . |