> For the complete documentation index, see [llms.txt](https://dev.ubidots.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://dev.ubidots.com/dashboards-and-widgets/html-canvas/code-editor.md).

# Code editor

The code editor has three tabs:

* HTML
* CSS
* JavaScript

Use each tab to write code in its corresponding language.

You can even use all three languages in the same file:

```html
<!DOCTYPE html>
<html>
<head>
<style>
body {
   background-color: lightblue;
}
h1 {
   color: white;
   text-align: center;
}
p {
   font-family: verdana;
   font-size: 20px;
}
</style>
</head>
<body>
<script>
  // Some javascript code
</script>
<h1> This is a h1 header </h1>
<p> This is a paragraph </p>
</body>
</html>
```

However, best practice is to separate the code into three files, one for each language. That is why the widget's code editor includes a dedicated tab for each one.


---

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```
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