---
title: "Simple Data Writer"
description: "Configure the JMeter Simple Data Writer listeners: properties, defaults, and practical usage notes for building reliable load tests."
url: https://docs.jmeter.ai/components/simple-data-writer/
lastUpdated: 2026-10-01
source: docs.jmeter.ai
---

# Simple Data Writer

*Part of the **Listeners** category. Also documented in context in the [full Component Reference](/user-manual/component-reference/#simple-data-writer).*

**TL;DR:** Simple Data Writer (the underlying engine of most listeners’ “Configure” dialog) writes sample results straight to a file in CSV or XML — the lightest-weight way to persist results without a GUI listener’s memory overhead during a real load test.

![Simple Data Writer](/images/screenshots/simpledatawriter.png)

This listener can record results to a file
but not to the UI.  It is meant to provide an efficient means of
recording data by eliminating GUI overhead.
When running in CLI mode, the `-l` flag can be used to create a data file.
The fields to save are defined by JMeter properties.
See the `jmeter.properties` file for details.

### Common gotchas

- **Never run GUI listeners (View Results Tree, Graph Results) during an actual load test** — they hold every sample in memory and can OOM the JVM or skew results. Use a file-writing listener like this one and analyze afterward.
- CSV output is far more compact than XML and is what the HTML Dashboard Report generator expects — stick with CSV unless something downstream specifically needs XML.
- Choose exactly which fields to save (response data, headers, etc.) — saving response bodies for every sample on a high-throughput test can produce enormous `.jtl` files fast.
- For turning the resulting file into a report, see [Generating the Dashboard Report](/user-manual/generating-dashboard/) and [HTML Dashboard Errors](/topics/errors/html-dashboard-generation-errors/) if generation fails.

## Related

- [Grafana / InfluxDB / Backend Listener](/topics/grafana-influx-backend-listener/)
- [Coordinated Omission Calculator](/tools/coordinated-omission/)
- [HTML Dashboard Errors](/topics/errors/html-dashboard-generation-errors/)
- [Full Component Reference](/user-manual/component-reference/)
- [Functions and Variables](/user-manual/functions/)