Setting a Custom 3DNS Domain on Tumblr

This guide provides comprehensive instructions on how to set up a custom domain on Tumblr using 3DNS, covering key topics such as DNS configurations, updating DNS settings, configuring Tumblr settings, and verification procedures.

How to Set Up a Custom Domain on Tumblr with 3DNS


You must own an onchain domain from 3DNS.

Before starting, it's important to know which DNS records you'll need to modify. The specific records depend on whether you're using a root domain or a subdomain:

Root Domain: You'll need to set up an A record and a CNAME record.

Root Domain DNS Configuration

Record TypeNameValuePurpose
A Record@ your root domain to Tumblr's server
CNAME Recordwwwdomains.tumblr.comRedirects 'www' prefix to Tumblr

Subdomain: A CNAME record is required.

Subdomain DNS Configuration

Record TypeNameValuePurpose
CNAME Record[subdomain]domains.tumblr.comPoints the subdomain (e.g., to Tumblr

Step 1. Update DNS Settings for your 3DNS Domain

Log into the 3DNS app (

Find and click on the Web tab.

Select Add DNS Record under the DNS Records tab.

Add the CNAME provided by Tumblr, the CNAME differs depending on your domain type.

After making the necessary modifications to the DNS records, ensure you select "Add Record" to save the changes.

Step 2: Configure Your Tumblr Settings

Sign into your Tumblr account. Click on the Account icon located at the top right corner of the page, then choose "Settings."

Enable the "Use a custom domain" option by turning on the switch next to it, and enter the domain or subdomain you previously configured. Then, click the "Save" button to proceed.

Step 3: Test and Verify

Once you've configured your custom domain, it may take up to 72 hours for Tumblr to verify your settings. During this period, you should regularly check to ensure everything is functioning correctly.