HAR to JMX File
Learn how to capture network traffic in Chrome as a HAR file and convert it to JMeter's JMX format using Blazemeter's conversion tool.
Mark
Performance Testing Expert
This guide walks through capturing network traffic in Chrome as a HAR file and converting it to Apache JMeter’s JMX format for performance testing.
What is a HAR File?
HAR (HTTP Archive) is a JSON-formatted archive file format for logging web browser interaction with a site. It captures all network requests, responses, headers, cookies, and timing information.
Capturing HAR Files
- Open Chrome’s Developer Tools (
Ctrl + Shift + I) - Navigate to the Network tab
- Browse through the pages you want to capture
- Right-click in the Network panel
- Select “Save all as HAR with content”
Converting to JMX Format
Apache JMeter does not natively support HAR files, so we need to convert them:
- Navigate to https://converter.blazemeter.com/
- Upload your HAR file
- Download the generated JMX file
Using the Converted File
Open the resulting JMX file in JMeter to access a test plan containing:
- All captured HTTP requests
- Cookies
- Headers
- Request parameters
Important Note
Unfiltered Chrome HAR exports produce raw recordings with extra attributes, requiring manual cleanup before optimal test plan use. You may need to:
- Remove unnecessary requests (static assets, tracking scripts)
- Clean up cookie handling
- Parameterize dynamic values
- Add appropriate assertions and listeners
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