Svelte actions and onMount can each be used if you want to manipulate or mutate a DOM node. We saw an example where we painted a QR code to an HTML canvas node, but you also might want to add event listeners or update the node’s styles. Svelte actions use a little less boilerplate code than an onMount method. Besides this, they are easier to share between components. Finally, they have a mechanism for updating in-built. This saves you have to add an extra beforeUpdate or similar.