---
number: 34054
slug: 34054-deno-2-1-preview-local-only
published: 2025-03-07
discussion: https://github.com/orgs/supabase/discussions/34054
labels:
  - edge functions
page: https://supabase.com/changelog/34054-deno-2-1-preview-local-only
---

# Deno 2.1 Preview **local only**

You can now try Deno 2.1 locally with Supabase CLI. The goal of local preview is to identify any regressions or missing functionality before we upgrade hosted version to Deno 2.1.

~The hosted version still uses Deno 1.4+, and if you deploy functions written with Deno 2.1, some of the features may not work.~

UPDATE 04/09/25: hosted version is now using Deno 2.1 - https://github.com/orgs/supabase/discussions/37941

### How to try

* Install Deno 2.1 or newer version on your machine (https://docs.deno.com/runtime/getting_started/installation/) 

* Go to your Supabase project. `cd my-supabase-project`

* Open `supabase/config.toml` and set `deno_version = 2`
```toml
[edge_runtime]
deno_version = 2
```

* All your existing functions should work as before.

*To scaffold a new function as a Deno 2 project:
```bash
deno init --serve hello-world
```

* Open `supabase/config.toml` and add the following:
```
[functions.hello-world]
entrypoint = "./functions/hello-world/main.ts"
```

* Open supabase/functions/hello-world/main.ts and modify line 10 to:
```typescript
if (url.pathname === "/hello-world") {
```

* Use `npx supabase@beta functions serve --no-verify-jwt` to start the dev server.

* Visit http://localhost:54321/functions/v1/hello-world.

* To run built-in tests, `cd supabase/functions/hello-world; deno test`

Please give it a try and report any bugs and feedback.