Why can't JavaScript .play() audio files on iPhone safari?

I've got a JavaScript web app working that plays some audio periodically like this:

var SOUND_SUCCESS = new Audio('success.mp3');
SOUND_SUCCESS.play();

This works great on desktop browsers (tested in Edge and Chrome), but it doesn't play on Safari on iPhone.

I've looked around Stack Overflow, and I found some answers from a couple of years ago that it's not possible to play audio from Safari unless you're in that full screen player. Is this still the case?

Solution 1:

To add to xingliang cai's response, here's a code sample I got to work for me (edited below to work on iOS14, thanks @AndrewL!):

const soundEffect = new Audio();
soundEffect.autoplay = true;

// onClick of first interaction on page before I need the sounds
// (This is a tiny MP3 file that is silent and extremely short - retrieved from https://bigsoundbank.com and then modified)
soundEffect.src = "data:audio/mpeg;base64,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";

// later on when you actually want to play a sound at any point without user interaction
soundEffect.src = 'path/to/file.mp3';

Solution 2:

iOS disables autoplay, instead requiring that play be initiated as part of a user interaction (e.g., you can start playback within a touchstart listener). There's a bit of documentation about this on Apple's developer documentation. There's also this article Overcoming iOS HTML5 audio limitations on IBM's developer site that has examples and more detail.