How to set up your first .io domain (with Heroku)

June 2013

.io Domains are all the rage in the startup/developer world. A couple of favourites include,, and

As the .com market is saturated, it opens up an opportunity to claim a domain name that you want for your project or startup.

Having shipped a couple of .io’s myself recently (, I thought I’d share the process of setting up your own (if you’re using Heroku).

1. See what .io domains are available

I use Domainr for this.

It searches for you in realtime across various domain extensions, including .com .io .co


2. Register your .io domain (with Gandi)

I shopped around and found Gandi to be the best price for a .io domain at $39 (£29) *

  • See the end of this post for a 30% discount code


3. Set up a zone file on Gandi

To point your Gandi .io domain to your server, you need to set up a new DNS zone file.

From your list of domains, select your new .io domain, then find the Zone files area to edit.


Click “Copy to edit” to make a new zone file. Since Gandi uses version control, you will need to make a new version to edit it. Give it any name you like.


If you’re using Heroku, you’ll want to add Heroku A records and the CNAME of your heroku app.

@ 10800 IN A
@ 10800 IN A
@ 10800 IN A
www 10800 IN CNAME

Just cut and paste this into your zone file and edit (use expert mode).

Remember you have to apply the zone file (“Use this version”) for it to become active.


4. Add the domain to Heroku

In your Heroku app settings add the www and naked domain name.


5. Tell the world you have a .io domain

That should be you ready for action. Time to submit it to Hacker News.

Bonus: 30% Off .io domains from Gandi

When I told Gandi about this post they were kind enough to offer a discount code for .io domains.

Use IO4LESS before July 31st 2013 for 30% off all .io domains on Gandi.

Do you have a .io domain? Share it below.

Further reading

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