# Migrate from Firebase Auth to Supabase

Migrate Firebase auth users to Supabase Auth.

Supabase provides several [tools](https://github.com/supabase-community/firebase-to-supabase/tree/main/auth) to help migrate auth users from a Firebase project to a Supabase project. There are two parts to the migration process:

- `firestoreusers2json` ([TypeScript](https://github.com/supabase-community/firebase-to-supabase/blob/main/auth/firestoreusers2json.ts), [JavaScript](https://github.com/supabase-community/firebase-to-supabase/blob/main/auth/firestoreusers2json.js)) exports users from an existing Firebase project to a `.json` file on your local system.
- `import_users` ([TypeScript](https://github.com/supabase-community/firebase-to-supabase/blob/main/auth/import_users.ts), [JavaScript](https://github.com/supabase-community/firebase-to-supabase/blob/main/auth/import_users.js)) imports users from a saved `.json` file into your Supabase project (inserting those users into the `auth.users` table of your `Postgres` database instance).

## Set up the migration tool \[#set-up-migration-tool]

1. Clone the [`firebase-to-supabase`](https://github.com/supabase-community/firebase-to-supabase) repository:

   ```bash
   git clone https://github.com/supabase-community/firebase-to-supabase.git
   ```

2. In the `/auth` directory, create a file named `supabase-service.json` with the following contents:

   ```json
   {
     "host": "database.server.com",
     "password": "secretpassword",
     "user": "postgres",
     "database": "postgres",
     "port": 5432
   }
   ```

3. On your project dashboard, click [Connect](/dashboard/project/_?showConnect=true\&method=session)

4. Under the Session pooler, click on the View parameters under the connect string. Replace the `Host` and `User` fields with the values shown.

5. Enter the password you used when you created your Supabase project in the `password` entry in the `supabase-service.json` file.

## Generate a Firebase private key \[#generate-firebase-private-key]

1. Sign in to your [Firebase Console](https://console.firebase.google.com/project) and open your project.
2. Click the gear icon next to **Project Overview** in the sidebar and select **Project Settings**.
3. Click **Service Accounts** and select **Firebase Admin SDK**.
4. Click **Generate new private key**.
5. Rename the downloaded file to `firebase-service.json`.

## Save your Firebase password hash parameters \[#save-firebase-hash-parameters]

1. Sign in to your [Firebase Console](https://console.firebase.google.com/project) and open your project.
2. Select **Authentication** (Build section) in the sidebar.
3. Select **Users** in the top menu.
4. At the top right of the users list, open the menu (3 dots) and click **Password hash parameters**.
5. Copy and save the parameters for `base64_signer_key`, `base64_salt_separator`, `rounds`, and `mem_cost`.

```text Sample
hash_config {
  algorithm: SCRYPT,
  base64_signer_key: XXXX/XXX+XXXXXXXXXXXXXXXXX+XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX==,
  base64_salt_separator: Aa==,
  rounds: 8,
  mem_cost: 14,
}
```

## Command line options

### Dump Firestore users to a JSON file \[#dump-firestore-users]

`node firestoreusers2json.js [<filename.json>] [<batch_size>]`

- `filename.json`: (optional) output filename (defaults to `./users.json`)
- `batchSize`: (optional) number of users to fetch in each batch (defaults to 100)

### Import JSON users file to Supabase Auth (Postgres: `auth.users`) \[#import-json-users-file]

`node import_users.js <path_to_json_file> [<batch_size>]`

- `path_to_json_file`: full local path and filename of JSON input file (of users)
- `batch_size`: (optional) number of users to process in a batch (defaults to 100)

## Notes

For more advanced migrations, including the use of a middleware server component for verifying a user's existing Firebase password and updating that password in your Supabase project the first time a user logs in, see the [`firebase-to-supabase` repo](https://github.com/supabase-community/firebase-to-supabase/tree/main/auth).

## Resources

- [Supabase vs Firebase](/alternatives/supabase-vs-firebase)
- [Firestore Data Migration](/docs/guides/platform/migrating-to-supabase/firestore-data)
- [Firestore Storage Migration](/docs/guides/platform/migrating-to-supabase/firebase-storage)

## Migrate to Supabase

[Contact us](https://forms.supabase.com/firebase-migration) if you need more help migrating your project.