Overview
Error Code and Error Type within the Catchpoint UI are used to improve the analysis of errors. They are used within Performance Charts and the Errors Module.
Difference
Error Code: Catchpoint displays two versions of the error message in the UI, a short version and a longer descriptive version. The longer more descriptive versions can be viewed on a scatterplot via the tooltip on the waterfall chart, in the Errors module, or on the data export. The shorter descriptions are displayed elsewhere.

JavaScript and Child Request failures are Error Types only and don't have any Error Codes.
Error Type: Error codes are grouped together by Error Type to allow for aggregate error analysis. Available Error Types are based on the selected Test Type. Error Codes are divided into the following types:
- DNS: An error occurred while resolving DNS.
- Connection: An error occurred connecting to the host.
- SSL: An error occurred during SSL negotiations.
- Response: An error occurred during the response from the server.
- Timeout: The test timed out waiting for the resources to load.
- Transaction: A transaction script error occurred.
- Validation: An alert enforced a test failure.
- System Limit: Test run exceeded system limits.
- JS: A JavaScript error occurred.
- Child Request Failure: An error occurred for a child request but did not cause a test failure.
- Other: Any error that does not get categorized into the above error types.