I have tried to add audio to a webpage of mine which is supposed to run automatically once the page is loaded, but it doesn't work.Feedback What I have tried: I have tried starting the audio via javascript, but I get the error: Uncaught TypeError: Cannot read property 'play' of null The script: Feedback To optimise pages on this blog I recently replaced the animated GIFs with auto-playing videos. It required a couple tries to get it right, so here’s how it works. The video below won’t autoplay.
To fix this we add the
However the video above still won’t autoplay on iOS Safari, Safari requires us to add the
We can try to hack around these autoplay limitations with some JavaScript, but that will only work if the JavaScript is run as a result of a user action. Automatically starting the playback of audio (or videos with audio tracks) immediately upon page load can be an unwelcome surprise to users. While autoplay of media serves a useful purpose, it should be used carefully and only when needed. In order to give users control over this, browsers often provide various forms of autoplay blocking. In this guide, we'll cover autoplay functionality in the various media and Web Audio APIs, including a brief overview of how to use autoplay and how to work with browsers to handle autoplay blocking gracefully. Autoplay blocking is not applied to 7 elements when the source media does not have an audio track, or if the audio track is muted. Media with an active audio track are considered to be audible, and autoplay blocking applies to them. Inaudible media are not affected by autoplay blocking.The term autoplay refers to any feature that causes audio to begin to play without the user specifically requesting that playback begin. This includes both the use of HTML attributes to autoplay media as well as the user of JavaScript code to start playback outside the context of handling user input. That means that both of the following are considered autoplay behavior, and are therefore subject to the browser's autoplay blocking policy:
and
The following web features and APIs may be affected by autoplay blocking:
From the user's perspective, a web page or app that spontaneously starts making noise without warning can be jarring, inconvenient, or off-putting. Because of that, browsers generally only allow autoplay to occur successfully under specific circumstances. As a general rule, you can assume that media will be allowed to autoplay only if at least one of the following is true:
Otherwise, the playback will likely be blocked. The exact situations that result in blocking, and the specifics of how sites become allowlisted vary from browser to browser, but the above are good guidelines to go by. For details, see the autoplay policies for Google Chrome and WebKit. Note: Put another way, playback of any media that includes audio is generally blocked if the playback is programmatically initiated in a tab which has not yet had any user interaction. Browsers may additionally choose to block under other circumstances. Now that we've covered what autoplay is and what can prevent autoplay from being allowed, we'll look at how your website or app can automatically play media upon page load, how to detect when autoplay fails to occur, and tips for coping when autoplay is denied by the browser. The simplest way to automatically play content is to add the attribute to your 8 or 7 element. This sets the 1 property on the element to 5, and when 1 is 5, the media will automatically begin to play as soon as possible after the following have occurred:
Example: The autoplay attributeAn 8 element using the 1 attribute might look like this:
Example 2: Detecting autoplay failureIf you rely on autoplay for anything important, or if autoplay failure will impact your app in any way, you will probably want to be able to tell when autoplay didn't begin. Unfortunately, in the case of the attribute, recognizing whether or not autoplay successfully began is tricky. There's not an event triggered when autoplay fails. Nor is there an exception thrown or a callback you can set up or even a flag on the media element that tells you if autoplay worked. All you can really do is examine a few values and make an educated guess as to whether or not autoplay worked. A better approach, if you're able to adjust the direction you look at things from, is to instead rely on knowing that playback of the media has successfully started, instead of when it fails to start. You can do this easily, by listening for the 1 event to be fired on the media element.The 1 event is sent both when the media is resumed after being paused and when autoplay occurs. That means that the first time the 1 event is fired, you know your media is being started for the first time after the page is opened.Consider this HTML for a media element:
Here we have a 7 element whose attribute is set, with an 6 event handler set up; the event is handled by a function called 7, which receives as input the 1 event. 7 looks like this:
After getting a reference to the video element from the 0 object's 1, the element's 6 handler is set to 3. This will prevent any future 1 events from being delivered to the handler. That could happen if the video is paused and resumed by the user or automatically by the browser when the document is in a background tab.At this point, your site or app can begin whatever it needs to do that relies upon the video having been started up. Note: This approach doesn't differentiate between autoplay and the user starting playback manually. The term "autoplay" also refers to scenarios in which a script tries to trigger the playback of media that includes audio, outside the context of handling a user input event. This is done by calling the media element's 5 method.Note: It is strongly recommended that you use the 1 attribute whenever possible, because support for autoplay preferences are more widespread for the 1 attribute than for other means of playing media automatically. It also lets the browser take responsibility for starting playback, letting it optimize the timing of that taking place.Example: Playing videoThis simple example plays the first 7 element found in the document. 5 won't let the playback begin unless the document has permission to automatically play media.
Example: Handling play() failuresIt's much easier to detect a failure to autoplay media when you use the 5 method to start it. 5 returns a 2 which is resolved once the media successfully begins to play, and is rejected when playback fails to begin (such as if autoplay is denied). When autoplay fails, you likely will want to offer a way for the user to manually tell the browser to ask the user to grant permission to play media.You might use code like this to accomplish the job:
The first thing we do with the result of 5 is make sure it's not 4. We check for this because in earlier versions of the HTML specification, 5 didn't return a value. Returning a promise to allow you to determine success or failure of the operation was added more recently. Checking for 4 prevents this code from failing with an error on older versions of web browsers.If the promise returned by 5 is resolved without error, the 8 clause is run and can begin whatever needs to be done when autoplay has begun.We then add a 9 handler to the promise. This looks at the error's 0 to see if it's 1. This indicates that playback failed due to a permission issue, such as autoplay being denied. If that's the case, we should present a user interface to let the user manually start playback; that's handled here by a function 2.Any other errors are handled as appropriate. If you want to start playing the video after the first interaction with the page, 3 might be used to achieve this:
In the Web Audio API, a website or app can start playing audio using the 4 method on a source node linked to the 5. Doing so outside the context of handling a user input event is subject to autoplay rules.In addition to the browser-side management and control over autoplay functionality described above, a web server can also express its willingness to allow autoplay to function. The HTTP 6 header's 1 directive is used to control which domains, if any, can be used to autoplay media. By default, the 1 Permissions Policy is set to 9, indicating that autoplay is permitted as they're hosted on the same domain as the document.You can also specify an empty allowlist ( 0) to disable autoplay entirely, 1 to allow autoplay from all domains, or one or more specific origins from which media can be automatically played. These origins are separated by space characters.Note: The specified Permissions Policy applies to the document and every 0 nested within it, unless those frames include an , which sets a new Permissions Policy for that frame and all frames nested within it.When using the attribute on an 0 to specify a Permissions Policy for that frame and its nested frames, you can also specify the value 6 to allow autoplay of media only from the same domain as that specified by the frame's attribute.To use the 6 header to only allow media to autoplay from the document's origin:
To do the same for an 0:
Adding Fullscreen API permission to the previous example results in a 6 header like the following if fullscreen access is allowed regardless of the domain; a domain restriction can be added as well as needed. 0The same permissions, grated using the 0 element's 3 property, look like this: 1The 6 header to allow media to be played from both the document's (or 0's) own domain and 5 looks like this: 2An 0 can be written to specify that this autoplay policy should be applied to itself and any child frames would be written thusly: 3Setting the 1 Permissions Policy to 0/ 9 disables autoplay entirely for the document or 0 and all nested frames. The HTTP header is: 4Using the 0's 3 attribute: 5Tips and recommended best practices to help you make the most of working with autoplay are offered here. A common use case for autoplay is to automatically begin to play a video clip that goes along with an article, an advertisement, or a preview of the page's main functionality. To autoplay videos like these, you have two options: don't have an audio track, or have an audio track but configure the 7 element to mute the audio by default, like this: 6This video element is configured to include the user controls (typically play/pause, scrubbing through the video's timeline, volume control, and muting); also, since the attribute is included, and the attribute that is required for autoplay in Safari, the video will autoplay but with the audio muted. The user has the option, however, of re-enabling the audio by clicking on the unmute button in the controls. Browsers may have preferences that control the way autoplay works, or how autoplay blocking is handled. Here, any such preferences that may be of special significance or importance to you as a web developer are listed. These include any that may aid in testing or debugging as well as any that could be set in a way that you need to be prepared to handle. 6A Boolean preference which specifies whether the 7 property is exposed to the web. This is currently 8 by default (except in nightly builds, where it's 5 by default). If this is 8, the 01 property is missing from the 02 interface, and is thus not present on either 8 or 7 elements. 05This Boolean preference, if 5, allows browser extensions' background scripts to autoplay audio media. Setting this value to 8 disables this capability. The default value is 5. 09A Boolean preference which if 5 (the default) allows audio media which is currently muted to be automatically played. If this has been changed to 8, media with an audio track will not be permitted to play even if muted. 12A Boolean preference which indicates whether media playback is blocked when started on a background tab. The default value, 5, means that even when otherwise available, autoplay won't take place until after a tab is brought to the foreground. This prevents the distracting situation in which a tab begins playing sound and the user can't find the tab among all their tabs and windows.
How do I get HTML to automatically play audio?The autoplay attribute is a boolean attribute. When present, the audio will automatically start playing as soon as it can do so without stopping.
Why autoplay is not working in HTML?Chrome does not allow autoplay if the video is not muted. So to autoplay video you need to set both autoplay and muted attribute.
How do I autoplay audio in Chrome HTML?Just add an invisible iframe with an . mp3 as its source and allow="autoplay" before the audio element. As a result, the browser is tricked into starting any subsequent audio file.
How do I enable autoplay audio in Chrome?Enable Chrome to allow sound.. Click Lock in the address bar of your Chrome browser.. Click Site Settings.. Under Sound, select Allow.. |