Performance testing
Set up performance tests and identify potential bottlenecks or issues with your APIs.
Overview
How does your API perform under pressure? This template helps you simulate real-world traffic and analyze how your API handles load—directly within Postman’s built-in Collection Runner. No external tools, no cloud setup. You can simulate multiple virtual users (VUs), control the traffic profile (fixed or ramp-up), and visualize real-time performance metrics like response times, requests per second, and error rates.
Because performance tests run locally from your machine, they’re ideal for testing internal services—behind firewalls, in staging environments, or anywhere cloud-based tools can’t reach.
You’ll learn how to:
Simulate small and large payloads
Use Postman’s Performance tab to configure and run traffic profiles
Analyze key metrics like P95, P99, throughput, and error rates
Identify bottlenecks before they hit production
💡 Ideal for backend developers, QA engineers, and platform teams testing internal or public APIs—especially in firewalled, enterprise, or pre-prod environments.
What is API performance testing?
API performance testing measures how your API behaves under varying load conditions. It helps answer critical questions like:
How fast do endpoints respond on average?
Do response times degrade as load increases?
Can the API sustain a realistic level of traffic?
Where are the performance bottlenecks or failure points?
Postman now lets you answer these interactively with:
Virtual users executing your requests in parallel
Configurable load durations and ramp-up profiles
Live visual feedback on throughput, latency, and failures
What’s in this template?
This template includes:
Two sample requests:
Small query params: Simulates a lightweight request
Large query params: Simulates a heavier payload or complex input
Pre-written test scripts to capture response time
Pre-configured setup for running tests with virtual users
A guided experience for using the Performance tab in the Collection Runner
Instructions for customizing requests and scaling up test conditions
How to use this template
Step 1: Replace the sample URLs Update the requests with your actual API endpoints. Adjust query parameters or payload size to reflect real use cases.
Step 2: Open the Collection Runner In the Postman app, click Run Collection → switch to the Performance tab.
Step 3: Configure your test
Virtual users (VUs): How many parallel users to simulate
Duration: How long the test should run
Load profile: Fixed (steady load) or Ramp-up (gradually increasing traffic)
Step 4: Run the test and watch live metrics View real-time charts showing:
Avg response time
Requests per second (throughput)
Error rate
Step 5: Analyze results Once the run completes, inspect:
P95 and P99 latency
Min/max/average response times
Request-level drilldowns to spot problematic endpoints
Error breakdowns and bottlenecks
Step 6 (Optional): Automate over time While Postman’s Performance tab is currently GUI-only, you can still:
Use Newman for scheduled or CI/CD functional tests
Export results and incorporate them into performance dashboards
Understanding Key Metrics
Metric | What it tells you |
P95 | 95% of requests were faster than this value—shows slow outliers |
P99 | 99% of requests were faster—pinpoints rare but extreme latency |
Requests/sec | How many requests your API can serve per second |
Error rate | % of requests with 4XX/5XX errors or failed executions |
Frequently Asked Questions
Who can use the performance testing template?
The performance testing template is designed for:
Quality engineers
Backend developers
Fullstack developers
Performance testing vs load testing: What's the difference?
Performance testing and load testing are related. However, these two testing approaches are distinct. Let's look at the differences.
Performance testing evaluates the API's performance in terms of speed, response time, and scalability under various conditions, including load testing scenarios.
On the other hand, load testing specifically targets testing the API's performance under different loads, such as a high number of concurrent users or large data volumes, to assess its ability to handle real-world usage.
Learn more about testing API performance here.
Can I simulate multiple users hitting the API at once?
Yes. Postman now supports virtual users (VUs) that execute your requests in parallel—no need for external load testing tools.
Can I test APIs behind a firewall?
Yes. Since the test runs locally from your machine, you can test internal or protected endpoints with no special setup.
Can I view past test results?
Yes. Postman automatically saves previous performance test runs so you can compare and track over time.
Can I calculate P95/P99 inside Postman?
Postman surfaces these in the metrics dashboard automatically—no need to export or calculate manually.
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