---
title: "HTML Assertion"
description: "Configure the JMeter HTML Assertion assertions: properties, defaults, and practical usage notes for building reliable load tests."
url: https://docs.jmeter.ai/components/html-assertion/
lastUpdated: 2026-10-01
source: docs.jmeter.ai
---

# HTML Assertion

*Part of the **Assertions** category. Also documented in context in the [full Component Reference](/user-manual/component-reference/#html-assertion).*

![HTML Assertion](/images/screenshots/assertion/HTMLAssertion.png)

The HTML Assertion allows the user to check the HTML syntax of the response data using JTidy.

| Name | Required | Description |
| --- | --- | --- |
| Name | No | Descriptive name for this element that is shown in the tree. |
| doctype | Yes | `omit`, `auto`, `strict` or `loose` |
| Format | Yes | `HTML`, `XHTML` or `XML` |
| Errors only | Yes | Only take note of errors? |
| Error threshold | Yes | Number of errors allowed before classing the response as failed |
| Warning threshold | Yes | Number of warnings allowed before classing the response as failed |
| Filename | No | Name of file to which report is written |

## Related

- [Assertions & SLA Validation](/topics/jmeter-assertions-guide/)
- [Full Component Reference](/user-manual/component-reference/)
- [Functions and Variables](/user-manual/functions/)