Realms in Zulip

Zulip allows multiple realms to be hosted on a single instance. Realms are the Zulip codebase’s internal name for what we refer to in user-facing documentation as an organization (the name “realm” comes from Kerberos).

Wherever possible, we avoid using the term realm in any user-facing string or documentation; “Organization” is the equivalent term used in those contexts (and we have linters that attempt to enforce this rule in translatable strings). We may in the future modify Zulip’s internals to use organization instead.

The production docs on multiple realms are also relevant reading.

Creating realms

There are two main methods for creating realms.

  • Using unique link generator

  • Enabling open realm creation


One can host multiple realms in a Zulip server by giving each realm a unique subdomain of the main Zulip server’s domain. For example, if the Zulip instance is hosted at, and the subdomain of your organization is acme you can would for accessing the organization.

For subdomains to work properly, you also have to change your DNS records so that the subdomains point to your Zulip installation IP. An A record with host name value * pointing to your IP should do the job.

We also recommend upgrading to at least Zulip 1.7, since older Zulip releases had much less nice handling for subdomains. See our docs on using subdomains for user-facing documentation on this.

Working with subdomains in development environment

Zulip’s development environment is designed to make it convenient to test the various Zulip configurations for different subdomains:

  • Realms are subdomains on *, just like *

  • The root domain (like itself) is itself.

  • The default realm is hosted on localhost:9991 rather than, using the REALM_HOSTS feature feature.

Details are below.

By default, Linux does not provide a convenient way to use subdomains in your local development environment. To solve this problem, we use the domain, which has a wildcard A record pointing to You can use to connect to your Zulip development server instead of localhost. The default realm with the Shakespeare users has the subdomain zulip and can be accessed by visiting

If you are behind a proxy server, this method won’t work. When you make a request to load in your browser, the proxy server will try to get the page on your behalf. Since points to the proxy server is likely to give you a 503 error. The workaround is to disable your proxy for * The DNS lookup should still work even if you disable proxy for * If it doesn’t you can add records in /etc/hosts file. The file should look something like this.    localhost

These records are also useful if you want to e.g. run the Puppeteer tests when you are not connected to the Internet.