Custom domain configuration in Firebase - Commands & Configuration

Introduction

Custom domain configuration lets you use your own website address instead of the default Firebase URL. This makes your site look professional and easier to remember.

When you want your website to have a branded address like www.myapp.com instead of myapp.firebaseapp.com

When you want to improve trust with visitors by showing your own domain name

When you want to use HTTPS with your custom domain for secure connections

When you want to manage your website and domain settings in one place

When you want to link your Firebase hosting to a domain you already own

Commands

This command creates a new hosting site in Firebase for your app. It prepares Firebase to link your custom domain.

Terminal

firebase hosting:sites:create my-app-site

Expected Output

✔ Hosting site my-app-site created successfully

This deploys your website to the live channel of the hosting site you created. It makes your site ready to connect with your custom domain.

Terminal

firebase hosting:channel:deploy live --site my-app-site

Expected Output

✔ Deploy complete!

Project Console: https://console.firebase.google.com/project/my-app/hosting/sites/my-app-site

→

--site - Specifies which hosting site to deploy to

This command starts the process to link your custom domain to your Firebase hosting site. Firebase will give you DNS records to add to your domain provider.

Terminal

firebase hosting:domain:add www.mycustomdomain.com --site my-app-site

Expected Output

✔ Domain www.mycustomdomain.com added to site my-app-site

Please add the following DNS records to your domain provider to verify ownership and enable hosting.

→

--site - Specifies which hosting site to link the domain to

This command shows the list of custom domains linked to your hosting site and their verification status.

Terminal

firebase hosting:domain:list --site my-app-site

Expected Output

Domain Name           Status

www.mycustomdomain.com  Pending Verification

→

--site - Shows domains for the specified hosting site

Key Concept

If you remember nothing else from this pattern, remember: you must add the DNS records Firebase gives you to your domain provider to verify and activate your custom domain.

Common Mistakes

Not adding the DNS records to the domain provider after running the domain:add command

Without DNS records, Firebase cannot verify your domain ownership and the custom domain won't work.

Copy the DNS records Firebase shows and add them exactly to your domain provider's DNS settings.

Deploying to the default hosting site instead of the site linked to the custom domain

Your custom domain points to a specific hosting site, so deploying elsewhere means your domain won't show the updated site.

Always use the --site flag with deploy commands to target the correct hosting site.

Summary

Create a Firebase hosting site for your app using firebase hosting:sites:create.

Deploy your website to the hosting site with firebase hosting:channel:deploy.

Add your custom domain to the hosting site with firebase hosting:domain:add and get DNS records.

Add the DNS records to your domain provider to verify ownership and activate the domain.

Check domain status with firebase hosting:domain:list.

Practice

1. What is the main purpose of configuring a custom domain in Firebase Hosting?

easy

A. To enable Firebase Authentication for your app

B. To increase the storage capacity of your Firebase project

C. To create a new Firebase project automatically

D. To use your own website address instead of the default Firebase URL

Solution

1. Step 1: Understand Firebase Hosting default URLs

   Firebase Hosting provides a default URL, but it is not personalized.

2. Step 2: Purpose of custom domain

   Configuring a custom domain lets you use your own website address, making it easier for users to find your site.

3. Final Answer:

   To use your own website address instead of the default Firebase URL -> Option D

4. Quick Check:

   Custom domain = personal website address [OK]

Hint: Custom domain means your own website address, not Firebase default [OK]

Common Mistakes:

• Confusing custom domain with Firebase project storage
• Thinking it enables authentication automatically
• Assuming it creates a new Firebase project

2. Which DNS record type is commonly required to verify domain ownership when setting up a custom domain in Firebase Hosting?

easy

A. CNAME record

B. MX record

C. TXT record

D. A record

Solution

1. Step 1: Identify verification method

   Firebase asks you to add a DNS record to prove you own the domain.

2. Step 2: Common DNS record for verification

   TXT records are used to store text data for verification purposes.

3. Final Answer:

   TXT record -> Option C

4. Quick Check:

   Domain verification uses TXT record [OK]

Hint: Verification usually needs a TXT DNS record [OK]

Common Mistakes:

• Using MX record which is for email routing
• Confusing CNAME with verification record
• Using A record which points IP address

3. You added a CNAME record pointing www.example.com to ghs.googlehosted.com as Firebase instructed. What will happen when users visit www.example.com after DNS propagation?

medium

A. Users will get a DNS error and cannot reach the site

B. Users will see your Firebase hosted website at www.example.com

C. Users will be redirected to Firebase console login page

D. Users will see a default Firebase project page

Solution

1. Step 1: Understand CNAME record purpose

   CNAME points your domain to Firebase Hosting's server address.

2. Step 2: Effect after DNS propagation

   Once DNS updates, visiting www.example.com loads your Firebase hosted site.

3. Final Answer:

   Users will see your Firebase hosted website at www.example.com -> Option B

4. Quick Check:

   CNAME to Firebase = site loads correctly [OK]

Hint: CNAME to Firebase host means your site shows on your domain [OK]

Common Mistakes:

• Expecting DNS error after correct CNAME setup
• Thinking users get Firebase console page
• Assuming default Firebase page shows instead

4. You configured your custom domain but users report your site is not loading. Which of these is the most likely cause?

medium

A. You forgot to verify domain ownership by adding the required DNS record

B. You used an A record instead of a TXT record for verification

C. You deployed your Firebase project without enabling billing

D. You did not enable Firebase Authentication

Solution

1. Step 1: Check domain verification requirement

   Firebase requires domain ownership verification before serving your site.

2. Step 2: Effect of missing verification

   If verification is missing, Firebase will not serve your site on the custom domain.

3. Final Answer:

   You forgot to verify domain ownership by adding the required DNS record -> Option A

4. Quick Check:

   Missing verification = site won't load [OK]

Hint: Always verify domain ownership to activate custom domain [OK]

Common Mistakes:

• Confusing billing with domain verification
• Thinking authentication affects domain setup
• Using wrong DNS record type for verification

5. You want to configure both example.com and www.example.com to serve your Firebase hosted site securely. Which is the best approach?

hard

A. Add both domains in Firebase Hosting, verify ownership for both, and set DNS records accordingly

B. Only add www.example.com in Firebase and redirect example.com to it without verification

C. Add example.com only and rely on Firebase to automatically serve www.example.com

D. Use only example.com and set a CNAME record for www.example.com pointing to example.com

Solution

1. Step 1: Add both domains in Firebase Hosting

   Firebase requires each domain to be added and verified separately.

2. Step 2: Verify ownership and set DNS for both

   You must verify both domains and configure DNS records to point to Firebase Hosting.

3. Step 3: Ensure HTTPS works on both domains

   Firebase provisions SSL certificates for each verified domain to serve securely.

4. Final Answer:

   Add both domains in Firebase Hosting, verify ownership for both, and set DNS records accordingly -> Option A

5. Quick Check:

   Both domains added and verified = secure site on both [OK]

Hint: Add and verify each domain separately for full coverage [OK]

Common Mistakes:

• Assuming Firebase auto-serves unadded domains
• Skipping verification for one domain
• Using CNAME incorrectly for apex domain