# How to Use Performance Test at Work: Tech English (2026)

> A type of software testing that checks how well an application performs under specific conditions, measuring speed, stability, and resource usage when handling a certain amount of traffic or data.

- **Term:** performance test
- **Part of speech:** noun
- **Pronunciation:** /pərˈfɔːrməns test/
- **English level (CEFR):** B2
- **Register:** Neutral, Both
- **Region:** US and UK
- **Topic:** [Agile and project terms](https://app.speaktechenglish.com/learn/topics/agile-project-management-terms.md)
- **Lesson:** https://app.speaktechenglish.com/learn/performance-test
- **Last updated:** 2026-10-27

## Meaning

A type of software testing that checks how well an application performs under specific conditions, measuring speed, stability, and resource usage when handling a certain amount of traffic or data.

Performance testing is a critical phase in software development where engineers simulate real-world conditions to measure how the application behaves. This includes testing response times, throughput, CPU usage, and memory consumption. Teams run performance tests before major releases to identify bottlenecks and ensure the system can handle expected user loads without crashing or slowing down significantly. In tech companies, performance testing often happens in a dedicated testing environment that mimics production conditions. Engineers use specialized tools to generate load and monitor metrics. This is different from functional testing, which checks if features work—performance testing checks if they work fast enough and efficiently enough for users.

## When you hear it

Before we launch this new API endpoint, we need to run a performance test to ensure it can handle peak traffic.

## Examples

- **in a standup:** "We completed the performance test yesterday and found that the database queries need optimization."
- **in a code review:** "This change looks good, but we should performance test it with at least 10,000 concurrent users before merging."
- **in a team meeting:** "The performance test results show that our new feature can handle 5,000 requests per second, which exceeds our requirements."

## What native speakers say

- "We need to performance test this under load."
- "The performance test revealed some serious bottlenecks."
- "Once the performance test passes, we can ship it."

## Common mistakes

- ✗ "We performance tested the feature and it works great." → ✓ "We ran a performance test on the feature and the results look good." (Performance test is usually a noun; use 'run a performance test' or 'conduct a performance test' rather than as a verb.)
- ✗ "Performance testing shows the app works correctly." → ✓ "Performance testing shows the app responds quickly under load." (Performance testing measures speed and efficiency, not functional correctness. Use functional testing or unit tests for that.)
- ✗ "We do performance test every day." → ✓ "We run performance tests before each release." (Performance tests are typically run periodically before releases, not constantly, due to their resource intensity.)

## Be careful

Do not confuse with functional testing. Performance testing measures speed and efficiency under load, not whether features work correctly.

## Word forms

| Part of speech | Word | Example |
| --- | --- | --- |
| noun | performance test | The performance test revealed that our server could only handle 500 concurrent users. |
| noun | performance testing | Performance testing is essential before any major release to production. |
| verb | run/conduct a performance test | We ran a performance test on the new API and found response times to be acceptable. |


## Collocations

- **run a performance test**: Most common verb phrase meaning to execute or conduct the test.
- **performance test results**: The data and findings from the test, often presented in reports.
- **performance test environment**: The dedicated setup where tests are conducted, separate from production.
- **performance test metrics**: The specific measurements like response time, throughput, and CPU usage.
- **load performance test**: Testing how the system performs under heavy user load.

## Synonyms

- **load test**: Overlapping term that specifically focuses on how the system handles increased traffic.
- **stress test**: Tests the system beyond normal capacity to find breaking points; more extreme than performance testing.
- **benchmark test**: Measures performance against a standard or baseline for comparison purposes.

## Opposites

- functional test
- unit test

## Practice

This lesson has 4 practice exercises with instant feedback on the page: https://app.speaktechenglish.com/learn/performance-test

## FAQ

### What exactly does performance test measure?

A performance test measures how well software performs under specific conditions. This includes metrics like response time (how long it takes to respond to a request), throughput (how many requests it can handle per second), CPU usage, memory consumption, and stability. It simulates real-world usage patterns to ensure the application meets speed and efficiency requirements.

### How is performance testing different from functional testing?

Functional testing checks whether features work correctly (do the buttons do what they should?). Performance testing checks whether they work fast and efficiently (can the system handle 1,000 users simultaneously without slowing down?). You need both types before releasing software.

### When should you run a performance test?

Performance tests should run before major releases, after significant code changes, and when adding new features that might impact system resources. They typically happen in a staging or testing environment that mimics production conditions, not in production itself.

### What tools do engineers use for performance testing?

Common tools include JMeter, LoadRunner, Gatling, and k6. These tools can simulate thousands of virtual users, generate load on the system, and monitor performance metrics in real time.

### Is performance test formal or informal language?

Performance test is neutral, professional language used in both formal documentation and casual workplace conversations. It is the standard term used in tech companies worldwide.


## Related

- [load test](https://app.speaktechenglish.com/learn/load-test.md)
- [QA](https://app.speaktechenglish.com/learn/qa.md)
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