SvelteKit: Cannot prerender pages with actions

Quick fix

Read the commands before running them. Anything that restarts a service, deletes data or changes permissions should be tried on a non-production system first.

// The setting is inherited, so find where it was turned on
// src/routes/+layout.js
export const prerender = true;

// Opt the one route back out
// src/routes/contact/+page.server.js
export const prerender = false;
export const actions = {
  default: async ({ request }) => { /* ... */ }
};

# The build lists every page it tried to prerender and why
npm run build 2>&1 | grep -A3 prerender

# If the whole site is static, move the form to a separate service and
# post to it directly: an adapter-static build has nowhere to run actions
# https://svelte.dev/docs/kit/adapter-static

How to diagnose Svelte errors

Svelte errors mostly arise at the compiler's boundaries: the $ store prefix only works on real stores in component context, and SvelteKit's load functions run in two different environments with different capabilities. A 500 from a load function usually means server-only code (a database client, a secret, fs) reached a universal load that also runs in the browser.

If the quick fix above does not resolve it, work through these steps. They apply to this whole class of error, not just to this one message, which is usually what saves the time.

1. Check whether the file is a universal load (+page.js) or a server-only load (+page.server.js). Anything touching secrets or the filesystem belongs in the latter.
2. Read the full server-side stack trace in the terminal, not just the browser's 500 page: SvelteKit hides details in production for security.
3. For $ prefix errors, confirm the value is an actual store with a subscribe method and that you are inside a component, not a plain module.
4. Use $env/static/private and $env/dynamic/private for secrets so the compiler enforces the server-only boundary for you.
5. Reproduce with vite build && vite preview; dev-mode behaviour differs meaningfully from the production build.

Tools worth reaching for

• vite build && vite preview
• SvelteKit terminal logs
• svelte-check
• $env/static/private

Authoritative references

Primary documentation for this error, worth reading before applying any fix in production.

📖 svelte.dev

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See all 10 Svelte errors →

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