> **Note:** This document is only a reference for available options. To learn about passing options to Video.js, see [the setup guide](setup.md#options).
Each of these options is also available as a [standard `<video>` element attribute][video-attrs]; so, they can be defined in all three manners [outlined in the setup guide](setup.md#options). Typically, defaults are not listed as this is left to browser vendors.
Determines whether or not the player has controls that the user can interact with. Without controls the only way to start the video playing is with the `autoplay` attribute or through the Player API.
A URL to an image that displays before the video begins playing. This is often a frame of the video or a custom title screen. As soon as the user hits "play" the image will go away.
Start loading the video immediately (if the browser supports it). Some mobile devices will not preload the video in order to protect their users' bandwidth/data usage. This is why the value is called 'auto' and not something more conclusive like `'true'`.
_This tends to be the most common and recommended value as it allows the browser to choose the best behavior._
Load only the meta data of the video, which includes information like the duration and dimensions of the video. Sometimes, the meta data will be loaded by downloading a few frames of video.
Puts the player in [fluid](#fluid) mode and the value is used when calculating the dynamic size of the player. The value should represent a ratio - two numbers separated by a colon (e.g. `"16:9"` or `"4:3"`).
Video.js indicates that the user is interacting with the player by way of the `"vjs-user-active"` and `"vjs-user-inactive"` classes and the `"useractive"` event.
The `inactivityTimeout` determines how many milliseconds of inactivity is required before declaring the user inactive. A value of `0` indicates that there is no `inactivityTimeout` and the user will never be considered inactive.
> Type: `string`, Default: browser default or `'en'`
A [language code][lang-codes] matching one of the available languages in the player. This sets the initial language for a player, but it can always be changed.
Learn more about [languages in Video.js](languages.md).
Customize which languages are available in a player. The keys of this object will be [language codes][lang-codes] and the values will be objects with English keys and translated values.
Learn more about [languages in Video.js](languages.md).
> **Note**: Generally, this option is not needed and it would be better to pass your custom languages to `videojs.addLanguage()`, so they are available in all players!
This supports having plugins be initialized automatically with custom options when the player is initialized - rather than requiring you to initialize them manually.
Normally, the fact that HTML5 comes before Flash in the `techOrder` would mean Video.js would look for a compatible _source_ for HTML5 and would pick either the MP4 or WebM video (depending on browser support) only falling back to Flash if no compatible source for HTML5 was found.
However, because the `sourceOrder` is `true`, Video.js flips that process around. It will look for a compatible _tech_ for each source in order. Presumably, it would first find a match between the FLV (since it's first in the source order) and the Flash tech.
An array of objects that mirror the native `<video>` element's capability to have a series of child `<source>` elements. This should be an array of objects with the `src` and `type` properties. For example:
Defines the order in which Video.js techs are preferred. By default, this means that the `Html5` tech is preferred, but Video.js will fall back to `Flash` if no `Html5`-compatible source can be found.
The Video.js player is a component. Like all components, you can define what children it includes, what order they appear in, and what options are passed to them.
If an `Array` - which is the default - this is used to determine which children (by component name) and in which order they are created on a player (or other component):
```js
// The following code creates a player with ONLY bigPlayButton and
The `children` options can also be passed as an `Object`. In this case, it is used to provide `options` for any/all children, including disabling them with `false`:
Components can be given custom options via the _lower-camel-case variant of the component name_ (e.g. `controlBar` for `ControlBar`). These can be nested in a representation of grandchild relationships. For example, to disable the fullscreen control:
Video.js playback technologies (i.e. "techs") can be given custom options as part of the options passed to the `videojs` function. They should be passed under the _lower-case variant of the tech name_ (e.g. `"flash"` or `"html5"`).
This is not used in most implementations, but one case where it may be is dictating where the Video.js SWF file is located for the `Flash` tech:
Can be set to `false` to force emulation of text tracks instead of native support. The `nativeCaptions` option also exists, but is simply an alias to `nativeTextTracks`.
