sveltejs/kit · warning

'${id}' has no `+page`, so there is no code to preload. If y

Error message

'${id}' has no `+page`, so there is no code to preload. If you meant to warm up an endpoint, request it with `fetch` instead.

What it means

`preloadData()`/`preloadCode()` take route IDs, not URL pathnames. If the given ID resolves to an endpoint-only route (no `+page` file), there is no client code to preload, so SvelteKit warns and returns without loading anything, suggesting `fetch` for warming up endpoints.

Source

Thrown at packages/kit/src/runtime/client/client.js:2869

 * Returns a Promise that resolves when the modules have been imported.
 *
 * @param {import('$app/types').RouteId} id
 * @returns {Promise<void>}
 */
export async function preloadCode(id) {
	if (DEV && id[0] !== '/') {
		throw new Error(
			`argument passed to preloadCode must be a route ID (i.e. "/blog/[slug]" rather than "blog/[slug]")`
		);
	}

	const route = __SVELTEKIT_CLIENT_ROUTING__
		? routes.find((r) => r.id === id)
		: (route_id_cache.get(id) ?? (await load_route_by_id(id)));

	if (route === ENDPOINT_ONLY) {
		if (DEV) {
			console.warn(
				`'${id}' has no \`+page\`, so there is no code to preload. If you meant to warm up an ` +
					`endpoint, request it with \`fetch\` instead.`
			);
		}

		return;
	}

	if (!route) {
		if (DEV) {
			// warn rather than throw, since under client routing an endpoint-only route id is
			// indistinguishable from a typo — the client manifest only contains routes with a `+page`
			let message = `'${id}' did not match any route`;

			if (__SVELTEKIT_CLIENT_ROUTING__) {
				message += ` (note that routes without a \`+page\` have no code to preload)`;

				// the most common migration mistake is passing a pathname, which used to work

View on GitHub (pinned to 03f1687fe6)

Solutions

1. Use `fetch('/api/...')` to warm up endpoint-only routes instead of preloadData/preloadCode
2. Only preload route IDs that have a `+page` component
3. Add a route with a `+page` file if client-side preloading is actually desired

Example fix

// before
await preloadData('/api/data');
// after
await fetch('/api/data');

// only preload routes that have a +page
const isEndpointOnly = (id) => id.includes('+server') && !id.includes('+page');
if (isEndpointOnly(id)) { await fetch(resolveRoute(id)); } else { await preloadData(id); }

function hasPage(id) { return typeof id === 'string' && id.includes('+page'); }

When it happens

Trigger: Calling `preloadData('/api/...')` or `preloadCode()` with the ID of a `+server.js`-only route in DEV; the resolver in packages/kit/src/runtime/client/client.js finds the route, sees `route === ENDPOINT_ONLY`, and warns.

Common situations: Preloading API endpoints by mistake assuming preload performs a request; passing pathname strings instead of route IDs after refactoring routes.

Related errors

• '${id}' did not match any route (note that routes without a
• Avoid using `history.pushState(...)` and `history.replaceSta
• Cannot build with ${JSON.stringify(file)} because Bun treats
• Cannot build with ${JSON.stringify(file)} because Bun treats
• Page options are ignored when `router.type === 'hash'` (${no

AI-assisted analysis of sveltejs/kit@03f1687fe6 (2026-09-02). Data as JSON: /api/errors/fd583b5d45204516. Report an issue: GitHub.