Custom domain configuration in Firebase - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a custom domain in Firebase Hosting?

A custom domain is a web address you own that you connect to your Firebase-hosted site, so visitors see your own URL instead of the default Firebase URL.

beginner

What is the first step to connect a custom domain to Firebase Hosting?

You add your domain in the Firebase Console under Hosting, then verify you own the domain by adding a DNS record at your domain provider.

beginner

Why do you need to update DNS records when configuring a custom domain?

Updating DNS records tells the internet to send visitors to Firebase servers when they enter your domain name, linking your domain to your Firebase site.

intermediate

What type of DNS records are commonly used to connect a custom domain to Firebase Hosting?

You usually add A records pointing to Firebase IP addresses or CNAME records pointing to Firebase hosting URLs, depending on your domain setup.

beginner

How does Firebase handle HTTPS for custom domains?

Firebase automatically provisions and renews SSL certificates for your custom domain, so your site is secure with HTTPS without extra setup.

What is the purpose of verifying domain ownership in Firebase?

A To prove you control the domain before linking it to Firebase Hosting

B To enable Firebase billing for the domain

C To create a new domain name

D To delete the domain from Firebase

Verifying ownership ensures only the rightful owner can connect the domain to Firebase Hosting.

Which DNS record type is NOT typically used to connect a custom domain to Firebase Hosting?

A MX record

B CNAME record

C A record

D TXT record

MX records are for email routing, not for connecting websites to hosting services.

What does Firebase do automatically after you connect a custom domain?

A Creates a new Firebase project

B Changes your domain registrar

C Provisions an SSL certificate for HTTPS

D Deletes your default Firebase URL

Firebase automatically sets up SSL certificates so your site is secure with HTTPS.

Where do you add DNS records to connect your domain to Firebase?

A In the Firebase Console

B In your website code

C In your Firebase project settings

D At your domain registrar or DNS provider

DNS records must be added where your domain's DNS is managed, usually your domain registrar.

What happens if you don’t update DNS records after adding a custom domain in Firebase?

A Your site will still work with the custom domain

B Visitors will see an error or the old site

C Firebase will update DNS automatically

D Your domain will be deleted

Without DNS updates, the internet won’t know to send visitors to Firebase, so the custom domain won’t work.

Explain the steps to configure a custom domain for a Firebase Hosting site.

Think about what you do in Firebase and what you do at your domain provider.

Why is it important to update DNS records when setting up a custom domain with Firebase?

Consider how the internet knows where to send visitors.

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