# Use Redoc CE in HTML
To render API documentation in an HTML page:
1. Paste the following template into an HTML file.
```html
Redoc CE
```
2. Replace the value of `spec-url` with either:
- a relative path to a local OpenAPI description file, for example: `spec-url=my-api.yaml`
- a full URL, for example: `http://petstore.swagger.io/v2/swagger.json`
If you use a relative path, Redoc CE requires an HTTP server to run API documentation locally.
To test the HTML file, open it in your browser.
If you use a relative path, to run the API documentation locally, you need to [simulate an HTTP server](/docs/redoc/v2.x/deployment/intro#local-http-server).
## Configure Redoc CE
Redoc CE is highly configurable - see the [full list of configuration options](/docs/redoc/v2.x/config).
To configure Redoc CE in HTML:
- Add the property names to the HTML tag.
The following example makes all the required properties display at the top of the list:
```html
```
You can add as many Redoc CE configuration properties as you need.
### Theme configuration
The `theme` configuration setting represents many nested options.
You can supply these options as a JSON string to the `theme` attribute.
For example, to change the sidebar color:
```html
```
Check out the [list of options for theme configuration](/docs/redoc/v2.x/config#theme-settings) and create the configuration that suits your API needs.
## Advanced options
### The Redoc CE object
As an alternative to the HTML tag, you can also initialise Redoc CE in a web page.
Use the Redoc CE object and invoke it from JavaScript.
Use this method to create dynamic content in a page.
It is also a way to attach the Redoc CE element to an existing container.
The Redoc CE object offers an `init` function:
```js
Redoc.init(specOrSpecUrl, options, element, callback)
```
Where:
- `specOrSpecUrl`: either a JSON object with the OpenAPI description, or a file name or URL to the
description in JSON or YAML format
- `options`: Redoc CE [configuration options](/docs/redoc/v2.x/config)
- `element`: DOM element Redoc CE is inserted into
- `callback`(optional): callback to be called after Redoc CE has been fully rendered, also called on errors with `error` as the first argument
To use the Redoc object:
- Call `Redoc.init()` from the JavaScript on a web page to add the element to a named container.
The following example is an HTML page with a `
` tag, and the script to add the Redoc object to it.
This example also sets the configuration for `expandResponses` so all 200 and 400 status responses are displayed with their details visible when the page loads.
```html
Redoc CE in action
```
### Self-host dependencies
You can reference the Redoc CE script in two ways.
Use a link to the files hosted on a CDN, or install Redoc CE in your `node-modules` folder.
Self-hosting may be useful when you need to host in a closed environment or have requirements around external dependencies.
**Use CDN**
To reference Redoc CE hosted on a CDN:
- In the `
```
**Self-host dependencies**
To host the dependencies yourself:
1. Install `redoc` using `npm` or `yarn`.
```sh
npm install redoc@2
```
2. Reference the Redoc CE script with a node modules link.
```html
```
## Resources
- **[Redoc CE deployment guide](/docs/redoc/v2.x/deployment/intro)** - Follow step-by-step instructions for setting up your Redoc CE project