In SvelteKit, `` elements (rather than framework-specific `` components) are used to navigate between the routes of your app. If the user clicks on a link whose `href` is 'owned' by the app (as opposed to, say, a link to an external site) then SvelteKit will navigate to the new page by importing its code and then calling any `load` functions it needs to fetch data. You can customise the behaviour of links with `data-sveltekit-*` attributes. These can be applied to the `` itself, or to a parent element. These options also apply to `
` elements with [`method="GET"`](form-actions#GET-vs-POST). ## data-sveltekit-preload-data Before the browser registers that the user has clicked on a link, we can detect that they've hovered the mouse over it (on desktop) or that a `touchstart` or `mousedown` event was triggered. In both cases, we can make an educated guess that a `click` event is coming. SvelteKit can use this information to get a head start on importing the code and fetching the page's data, which can give us an extra couple of hundred milliseconds — the difference between a user interface that feels laggy and one that feels snappy. We can control this behaviour with the `data-sveltekit-preload-data` attribute, which can have one of two values: - `"hover"` means that preloading will start if the mouse comes to a rest over a link. On mobile, preloading begins on `touchstart` - `"tap"` means that preloading will start as soon as a `touchstart` or `mousedown` event is registered The default project template has a `data-sveltekit-preload-data="hover"` attribute applied to the `` element in `src/app.html`, meaning that every link is preloaded on hover by default: ```html
%sveltekit.body%
``` Sometimes, calling `load` when the user hovers over a link might be undesirable, either because it's likely to result in false positives (a click needn't follow a hover) or because data is updating very quickly and a delay could mean staleness. In these cases, you can specify the `"tap"` value, which causes SvelteKit to call `load` only when the user taps or clicks on a link: ```html Get current stonk values ``` > [!NOTE] You can also programmatically invoke `preloadData` from `$app/navigation`. Data will never be preloaded if the user has chosen reduced data usage, meaning [`navigator.connection.saveData`](https://developer.mozilla.org/en-US/docs/Web/API/NetworkInformation/saveData) is `true`. ## data-sveltekit-preload-code Even in cases where you don't want to preload _data_ for a link, it can be beneficial to preload the _code_. The `data-sveltekit-preload-code` attribute works similarly to `data-sveltekit-preload-data`, except that it can take one of four values, in decreasing 'eagerness': - `"eager"` means that links will be preloaded straight away - `"viewport"` means that links will be preloaded once they enter the viewport - `"hover"` - as above, except that only code is preloaded - `"tap"` - as above, except that only code is preloaded Note that `viewport` and `eager` only apply to links that are present in the DOM immediately following navigation — if a link is added later (in an `{#if ...}` block, for example) it will not be preloaded until triggered by `hover` or `tap`. This is to avoid performance pitfalls resulting from aggressively observing the DOM for changes. > [!NOTE] Since preloading code is a prerequisite for preloading data, this attribute will only have an effect if it specifies a more eager value than any `data-sveltekit-preload-data` attribute that is present. As with `data-sveltekit-preload-data`, this attribute will be ignored if the user has chosen reduced data usage. ## data-sveltekit-reload Occasionally, we need to tell SvelteKit not to handle a link, but allow the browser to handle it. Adding a `data-sveltekit-reload` attribute to a link... ```html Path ``` ...will cause a full-page navigation when the link is clicked. Links with a `rel="external"` attribute will receive the same treatment. In addition, they will be ignored during [prerendering](page-options#prerender). ## data-sveltekit-replacestate Sometimes you don't want navigation to create a new entry in the browser's session history. Adding a `data-sveltekit-replacestate` attribute to a link... ```html Path ``` ...will replace the current `history` entry rather than creating a new one with `pushState` when the link is clicked. ## data-sveltekit-reset When navigating to internal links, SvelteKit mirrors the browser's default navigation behaviour: it will change the scroll position to 0,0 so that the user is at the very top left of the page (unless the link includes a `#hash`, in which case it will scroll to the element with a matching ID), and [reset focus](accessibility#Focus-management). In certain cases, you may wish to disable this behaviour. Adding a `data-sveltekit-reset="false"` attribute to a link... ```html Path ``` ...will preserve the current scroll position and focused element after the link is clicked. The attribute can also be used on a `` — for example a search form that submits as the user is typing, where you want to keep focus on the text input: ```html
``` In general, avoid preserving focus on links, since the focused element would be the `` tag (and not a previously focused element) and screen reader and other assistive technology users often expect focus to be moved after a navigation. You should also only use this attribute on elements that still exist after navigation. If the element no longer exists, the user's focus will be lost, making for a confusing experience for assistive technology users. ## Disabling options To disable any of these options inside an element where they have been enabled, use the `"false"` value: ```html
a b c
d e f
``` To apply an attribute to an element conditionally, do this: ```svelte
```