You don't have to give up your unique, brand-centric domain names for apps
deployed on Firebase App Hosting. You can use a custom domain (like
example.com or app.example.com) instead of a Firebase-generated domain for
your Firebase-hosted site. Firebase App Hosting provisions an SSL
certificate for each of your domains.
The rest of this document walks you through the steps to connect your custom domain.
Set up your domain for App Hosting
Make sure that you've completed the basic App Hosting setup tasks so that you have a Firebase App Hosting site in your Firebase project.
Step 1: Add custom domain
- Open your project's App Hosting page.
- Select an App Hosting backend using the View Dashboard option.
- Select the Settings tab, then click Add custom domain.
- Enter the custom domain name that you'd like to connect to your App Hosting site.
- (Optional) Check the box to redirect all requests on the custom domain to
a second specified domain (such that
example.comandwww.example.comredirect to the same content). - Click Continue to configure your DNS records and finish setting up your custom domain.
Step 2: Set up custom domain
The Add Custom Domain wizard of the Firebase console will show the necessary records that need to be updated to point your page to Firebase App Hosting. Add, remove, and save records from your domain in your DNS provider with the following inputs:
- Type: Add the provided DNS record.
Host: Enter your custom domain key for the records. The host you indicate is the domain on which you want to serve content; this domain can be an apex domain or subdomain. Your domain provider may list this term as "Host Name", "Name", or "Domain".
Value: Assign the provided value to your records. Your domain provider may list this term as "Data", "Points To", "Content", "Address", or "IP Address". The content of the value field varies by record type, with A and AAAA records having IP addresses as values while TXT records are strings.
Allow time for your SSL certificate to be provisioned. This typically takes a few hours, but can occasionally require up to 24 hours after you point your DNS to Firebase App Hosting. In most cases, propagation of your records and provisioning of your SSL certificate will happen within an hour, depending on your domain provider.
Wait for SSL certificate provisioning
App Hosting can take up to a few hours to provision an SSL certificate for your domain after you update your DNS records. In some cases, it could require up to 24 hours after you point your DNS to Firebase App Hosting.
You can view this certificate using the browser's security tools. While the domain is provisioning, you might see an invalid certificate or have issues connecting to your domain. This is a normal part of the process and will resolve after your domain's certificate is available.
Note: Firebase App Hosting automatically reprovisions SSL certs, as needed, for custom domains.
DNS record types
The App Hosting Custom Domain wizard could ask you to add 1 to 5 DNS records, depending on your domain's current configuration. A record's Type determines its function. These are the types of records App Hosting might ask for:
| Type | Description | Exclusive |
|---|---|---|
| A | These records contain IPv4 values (e.g. 8.8.8.8), which tell browsers what address to use when attempting to contact your domain. | Yes |
| AAAA | These records contain IPv6 values (e.g. 2001:4860:4860::8888), a different type of address record with roughly the same function as A records. App Hosting doesn't currently use AAAA records, but will ask you to remove any existing ones from our domain, if present. | Yes |
| CNAME | These records contain a separate domain name that should be used instead
of your current domain to resolve DNS queries. CNAME records are only allowed
on subdomains (e.g. www.example.com). App Hosting uses CNAME records for
two reasons:
|
Yes |
| TXT | These records allow you to attach arbitrary metadata to your domain. App Hosting allows you to use a specific format of TXT record, fah-claim=[UUID], to indicate which Custom Domain it should serve on your domain. |
No |
| CAA | These records function as an allowlist for specifying Certificate Authorities that are authorized to mint SSL certificates for your domain. App Hosting only requests CAA records if it's otherwise blocked from minting certificates for your domain. | No |
Your custom domain key
When adding or editing DNS records, different domain providers expect you to enter different inputs for the Host field within their DNS management sites. We've compiled common inputs from popular providers below. Refer to your domain provider's documentation for detailed instructions.
| Domain type | Custom domain key |
|---|---|
| Apex domain |
Common inputs include:
|
| Subdomain | Common inputs include:
|
Common domain providers
Here are some common domain providers and the types of input each might require. This information is kept up-to-date as much as possible, but refer to your domain provider's documentation for detailed instructions.
Status descriptions for custom domains
| Status | Description |
|---|---|
| Needs setup |
You may need to change a configuration with your DNS records.
|
| Pending | You correctly set up your custom domain, but Firebase App Hosting hasn't provisioned an SSL certificate. Occasionally, excessively restrictive CAA records can stall the minting of an SSL certificate for a custom domain. Ensure that the certificate authorities `letsencrypt.org` and `pki.goog` are allowed to create SSL certs for your domain. |
| Minting Certificate | An SSL certificate is being produced for your domain. |
| Connected | Your custom domain has the proper DNS records and has an SSL
certificate. |