--- description: Migrate a SvelteKit application from Vercel to Cloudflare Workers. Replace adapter-vercel with adapter-cloudflare. Includes a prompt for your coding agent. title: Migrate SvelteKit from Vercel to Cloudflare Workers image: https://developers.cloudflare.com/workers/static-assets/migration-guides/vercel-to-workers/sveltekit/og.png?v=7a68b8d01a7414e6 --- [Skip to content](#main-content) > Documentation Index > Fetch the complete documentation index at: https://developers.cloudflare.com/workers/llms.txt > Use this file to discover all available pages before exploring further. # Migrate SvelteKit from Vercel to Cloudflare Workers Last updated Nov 5, 2026|Copy as Markdown| [View as Markdown](https://developers.cloudflare.com/workers/static-assets/migration-guides/vercel-to-workers/sveltekit/index.md)| [Agent setup](https://developers.cloudflare.com/agent-setup/) This guide moves a [SvelteKit ↗︎](https://svelte.dev/docs/kit) application from Vercel to Cloudflare Workers. You replace `@sveltejs/adapter-vercel` or `@sveltejs/adapter-auto` with [`@sveltejs/adapter-cloudflare` ↗︎](https://svelte.dev/docs/kit/adapter-cloudflare). The adapter version depends on your SvelteKit major version: | SvelteKit version | Adapter | Configured in | Bindings | | --- | --- | --- | --- | | Earlier than 2 | None. Upgrade to SvelteKit 2 first. | — | — | | 2 | `@sveltejs/adapter-cloudflare@^7` | `svelte.config.js` | `event.platform.env` | | 3 | `@sveltejs/adapter-cloudflare@^8` | `vite.config.js` | `import { env } from "cloudflare:workers"` | ## Before you begin - Migrate hosting on your current SvelteKit major version. Do not combine the move with a SvelteKit major upgrade, unless your version is earlier than 2. - On SvelteKit 2, do not use automatic project configuration or `npx sv add`. Both install adapter version 8, which only works with SvelteKit 3. - Make sure `package.json` has a `name` field. Without it, `sv add` fails and automatic configuration does not install the adapter. - Review the steps in [Before you begin](https://developers.cloudflare.com/workers/static-assets/migration-guides/vercel-to-workers/#before-you-begin) that apply to every framework. ## Migrate with a coding agent Copy this prompt into your coding agent. The agent stops before it deploys. ```txt Migrate this SvelteKit app from Vercel to Cloudflare Workers (Workers with Static Assets, not Pages). 0. Detect the package manager from the lockfile () and install dependencies. If the lockfile comes from an older package manager major version, regenerate it in its own commit. With pnpm 10 or later, run `pnpm approve-builds esbuild workerd` if an install reports ERR_PNPM_IGNORED_BUILDS. If package.json has no "name", add one. 1. Detect the installed @sveltejs/kit version from node_modules/@sveltejs/kit/package.json. - 2.x or 3.x: keep that major version. Do not combine the hosting move with a SvelteKit major upgrade. - Earlier than 2 (1.x or 1.0.0-next.*): no Cloudflare Workers adapter supports it. Upgrade to the latest SvelteKit 2 in a separate commit, and keep the current adapter. Target @sveltejs/kit@^2, svelte@^5 (keep the legacy syntax), vite@^7, @sveltejs/vite-plugin-svelte@^6, typescript@^5, and svelte-check@^4. `npx sv migrate` is interactive and has no codemod for pre-1.0 APIs, so make these changes by hand: - kit.methodOverride and POST, PATCH, or DELETE exports in +page.server become named `export const actions`, with `action="?/name"`. - Custom form enhance functions become `enhance` from $app/forms. - $app/env becomes $app/environment. - `export const hydrate` and `export const router` become `csr`. - sveltekit:prefetch becomes data-sveltekit-preload-data. - src/hooks.js becomes src/hooks.server.js. - `throw error()` and `throw redirect()` become `error()` and `redirect()`. - Self-closing non-void tags, such as ``. Get `build` and `check` passing before you continue. 2. Remove Vercel: - Uninstall @sveltejs/adapter-vercel and @sveltejs/adapter-auto. - Port redirects and headers from vercel.json. Static rules go to static/_redirects and static/_headers. Dynamic rules go to src/hooks.server.ts. Then delete vercel.json and .vercel/. - Remove every Vercel route configuration (`export const config = { runtime, regions, split, memory, maxDuration, isr }`). List the ISR routes, and replace them with `export const prerender = true` or Cache-Control headers set with setHeaders. - Remove VERCEL_* environment variable usage and Vercel analytics. Tell me to turn on Cloudflare Web Analytics instead. 3. Install @sveltejs/adapter-cloudflare and wrangler as dev dependencies. Use @^7 for SvelteKit 2 and @^8 for SvelteKit 3. Do not use `npx sv add` or `wrangler setup` on SvelteKit 2. 4. Configure the adapter. On SvelteKit 3, use sveltekit({ adapter: adapter() }) in vite.config. On SvelteKit 2, set kit.adapter = adapter() in svelte.config.js. 5. Create wrangler.jsonc with "name" (the package.json name), "main": ".svelte-kit/cloudflare/_worker.js", "compatibility_date": "", "assets": { "binding": "ASSETS", "directory": ".svelte-kit/cloudflare" }, and "observability": { "enabled": true }. Do not add nodejs_compat. A compatibility date of 2026-08-04 or later already enables it. Add .wrangler/ and .dev.vars* to .gitignore. 6. Bindings: on SvelteKit 3, use `import { env, waitUntil } from "cloudflare:workers"`. On SvelteKit 2, use event.platform.env, and type App.Platform in src/app.d.ts as { env: Env; ctx: ExecutionContext; cf?: IncomingRequestCfProperties }. Run `npx wrangler types` before the first build. Add `/// ` to the top of src/app.d.ts instead of changing tsconfig "include". 7. Set these scripts: preview=" run build && wrangler dev", deploy=" run build && wrangler deploy", and cf-typegen="wrangler types". 8. Remove runtime file system access. Use read() from $app/server, or prerender. Do not use sharp at runtime. 9. If vercel.json had crons, tell me that adapter-cloudflare has no scheduled handler. Propose a separate Worker with a Cron Trigger that calls an authenticated SvelteKit endpoint. 10. Run ` run build`, ` run check`, and `npx wrangler dev --port `. Request every page, __data.json endpoint, form action, and asset with curl. For form actions, send an Origin header that matches the dev URL. Use http://localhost, not 127.0.0.1, because SvelteKit sets Secure cookies on other hosts. If a third-party API also fails on the live Vercel site, report it instead of fixing it. Rules: one commit per logical step; store local secrets in a gitignored .dev.vars file with placeholder values; never print secret values; do not deploy, log in, or change DNS. When you finish, list the files you changed, behavior changes from any SvelteKit upgrade, the Vercel features without an equivalent, the secrets I must set with `npx wrangler secret put `, and the deploy command. ``` ## Migrate manually 1. If your SvelteKit version is earlier than 2, upgrade to SvelteKit 2 first. For more information, refer to [Migrating to SvelteKit v2 ↗︎](https://svelte.dev/docs/kit/migrating-to-sveltekit-2). 2. Remove whichever of these adapters your project uses:npmyarnpnpmbun ``` npm uninstall @sveltejs/adapter-vercel @sveltejs/adapter-auto ``` ``` yarn remove @sveltejs/adapter-vercel @sveltejs/adapter-auto ``` ``` pnpm remove @sveltejs/adapter-vercel @sveltejs/adapter-auto ``` ``` bun remove @sveltejs/adapter-vercel @sveltejs/adapter-auto ``` Install the Cloudflare adapter that matches your SvelteKit version. On SvelteKit 2:npmyarnpnpmbun ``` npm i -D @sveltejs/adapter-cloudflare@^7 wrangler ``` ``` yarn add -D @sveltejs/adapter-cloudflare@^7 wrangler ``` ``` pnpm add -D @sveltejs/adapter-cloudflare@^7 wrangler ``` ``` bun add -d @sveltejs/adapter-cloudflare@^7 wrangler ``` On SvelteKit 3:npmyarnpnpmbun ``` npm i -D @sveltejs/adapter-cloudflare@^8 wrangler ``` ``` yarn add -D @sveltejs/adapter-cloudflare@^8 wrangler ``` ``` pnpm add -D @sveltejs/adapter-cloudflare@^8 wrangler ``` ``` bun add -d @sveltejs/adapter-cloudflare@^8 wrangler ``` 3. Configure the adapter. On SvelteKit 2, edit `svelte.config.js`: *svelte.config.jsjs* ```js import adapter from "@sveltejs/adapter-cloudflare"; /** @type {import('@sveltejs/kit').Config} */ export default { kit: { adapter: adapter(), }, }; ``` On SvelteKit 3, pass the adapter to the `sveltekit()` plugin in `vite.config.js` instead. 4. Create a Wrangler configuration file: ```jsonc { "$schema": "node_modules/wrangler/config-schema.json", "name": "", "main": ".svelte-kit/cloudflare/_worker.js", // Set this to today's date "compatibility_date": "2026-11-06", "assets": { "binding": "ASSETS", "directory": ".svelte-kit/cloudflare", }, "observability": { "enabled": true, }, } ``` ```toml "$schema" = "node_modules/wrangler/config-schema.json" name = "" main = ".svelte-kit/cloudflare/_worker.js" # Set this to today's date compatibility_date = "2026-11-06" [assets] binding = "ASSETS" directory = ".svelte-kit/cloudflare" [observability] enabled = true ``` 5. Generate types for your bindings before the first build:npmyarnpnpm ``` npx wrangler types ``` ``` yarn wrangler types ``` ``` pnpm wrangler types ``` 6. On SvelteKit 2, reference the generated types and declare the platform type in `src/app.d.ts`: *src/app.d.tsts* ```ts /// declare global { namespace App { interface Platform { env: Env; ctx: ExecutionContext; cf?: IncomingRequestCfProperties; } } } export {}; ``` 7. Delete `vercel.json` and every Vercel `export const config` block. Replace ISR routes with prerendering or `Cache-Control` headers. 8. Build your application and run it locally:npmyarnpnpm ``` npm run build ``` ``` yarn run build ``` ``` pnpm run build ``` npmyarnpnpm ``` npx wrangler dev ``` ``` yarn wrangler dev ``` ``` pnpm wrangler dev ``` 9. Deploy your application:npmyarnpnpm ``` npx wrangler deploy ``` ``` yarn wrangler deploy ``` ``` pnpm wrangler deploy ```
Upgrade checklist for SvelteKit versions earlier than 1.0 Pre-1.0 SvelteKit applications need these changes when you upgrade to SvelteKit 2: | Pre-1.0 API | SvelteKit 2 replacement | | --- | --- | | kit.methodOverride and POST/PATCH/DELETE exports | Named form actions with action="?/name" | | Custom form enhance helpers | enhance from $app/forms | | $app/env | $app/environment | | export const hydrate and export const router | export const csr | | sveltekit:prefetch | data-sveltekit-preload-data | | src/hooks.js | src/hooks.server.js | | throw error() and throw redirect() | error() and redirect() | | Self-closing non-void tags, such as <button /> | <button></button> | After the upgrade, cookies set by SvelteKit include Secure and SameSite=Lax. Cross-site form submissions return 403.
## Known issues - **The build fails with `Cannot read properties of undefined (reading 'assets')`.** You installed adapter version 8 on SvelteKit 2. Install `@sveltejs/adapter-cloudflare@^7`. - **The build fails with `Types file not found`.** Run `npx wrangler types` before you build. - **Cron jobs have no scheduled handler.** `adapter-cloudflare` does not export a `scheduled()` handler. Use a separate Worker with a [Cron Trigger](https://developers.cloudflare.com/workers/configuration/cron-triggers/) that calls an authenticated endpoint. - **Prerendered pages skip your hooks.** Workers serves prerendered pages as static assets, so `hooks.server.js` does not run for them. Vercel behaves the same way. ## Related resources - [SvelteKit framework guide](https://developers.cloudflare.com/workers/framework-guides/web-apps/sveltekit/) - [Migrate from Vercel to Workers](https://developers.cloudflare.com/workers/static-assets/migration-guides/vercel-to-workers/) Was this helpful? YesNo ## On this page [![](https://developers.cloudflare.com/_astro/logo.te5VL_aD.svg)Docs](https://developers.cloudflare.com/) ```json {"@context":"https://schema.org","@type":"TechArticle","@id":"https://developers.cloudflare.com/workers/static-assets/migration-guides/vercel-to-workers/sveltekit/#page","headline":"Migrate SvelteKit from Vercel to Cloudflare Workers","description":"Migrate a SvelteKit application from Vercel to Cloudflare Workers. Replace adapter-vercel with adapter-cloudflare. Includes a prompt for your coding agent.","url":"https://developers.cloudflare.com/workers/static-assets/migration-guides/vercel-to-workers/sveltekit/","inLanguage":"en","image":"https://developers.cloudflare.com/workers/static-assets/migration-guides/vercel-to-workers/sveltekit/og.png?v=7a68b8d01a7414e6","dateModified":"2026-11-05","publisher":{"@type":"Organization","name":"Cloudflare","description":"One platform for your apps, agents, and workforce. Build, secure, and scale without managing infrastructure","url":"https://www.cloudflare.com/","sameAs":["https://github.com/cloudflare","https://www.linkedin.com/company/cloudflare","https://x.com/cloudflare"],"logo":{"@type":"ImageObject","url":"https://developers.cloudflare.com/logo.svg"},"address":{"@type":"PostalAddress","streetAddress":"101 Townsend St","addressLocality":"San Francisco","addressRegion":"CA","postalCode":"94107","addressCountry":"US"},"contactPoint":[{"@type":"ContactPoint","contactType":"Customer Support","url":"https://support.cloudflare.com/","availableLanguage":["English"]},{"@type":"ContactPoint","contactType":"Sales","url":"https://www.cloudflare.com/contact/","availableLanguage":["English"]}]},"isPartOf":{"@type":"WebSite","@id":"https://developers.cloudflare.com/#website","name":"Cloudflare Docs","url":"https://developers.cloudflare.com/"}} ```