htmx/www/content/attributes/hx-vars.md
William Jackson 46badfe0b1
Add descriptions for attribute pages (#3158)
Descriptions for attribute pages
2025-02-07 17:07:13 -07:00

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Markdown

+++
title = "hx-vars"
description = """\
The hx-vars attribute in htmx allows you to dynamically add to the parameters that will be submitted with an AJAX \
request. This attribute has been deprecated. We recommend you use the hx-vals attribute that provides the same \
functionality with safer defaults."""
+++
**NOTE: `hx-vars` has been deprecated in favor of [`hx-vals`](@/attributes/hx-vals.md), which is safer by default.**
The `hx-vars` attribute allows you to dynamically add to the parameters that will be submitted with an AJAX request.
The value of this attribute is a comma separated list of `name`:`<expression>` values, the same as the internal
syntax of javascript [Object Literals](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Grammar_and_types#Object_literals).
```html
<div hx-get="/example" hx-vars="myVar:computeMyVar()">Get Some HTML, Including A Dynamic Value in the Request</div>
```
## Security Considerations
* The expressions in `hx-vars` are dynamically computed which allows you to add JavaScript code that will be executed. Be careful to **never** trust user input in your expressions as this may lead to a [Cross-Site Scripting (XSS)](https://owasp.org/www-community/attacks/xss/) vulnerability. If you are dealing with user input such as query strings or user-generated content, consider using [hx-vals](@/attributes/hx-vals.md) which is a safer alternative.
## Notes
* `hx-vars` is inherited and can be placed on a parent element.
* A child declaration of a variable overrides a parent declaration.
* Input values with the same name will be overridden by variable declarations.