Listeners

When JMeter runs a Sampler the Sampler produces a Sample Result containing metrics like:

• timestamp
• response time
• connect time
• time-to-first-byte or latency
• number of sent and received bytes
• response code and message
• etc.

Listeners capture the results produced by samplers and present them in various formats - tables, graphs, trees, or files. They are how you see what happened during a test.