DuckDNS is a free dynamic DNS service that lets you use an easy-to-remember name instead of a changing IP address. It is useful when your home connection’s public address changes: you can use a name such as yourhome.duckdns.org instead of remembering the new address.
It updates the IP address linked to that name. To connect to your home server, your internet connection, router, firewall and server also need to be set up correctly.
What is Duck DNS used for?
The DuckDNS website describes the service as free dynamic DNS. A DDNS updater sends your current IP address to DuckDNS. Your chosen name, called a hostname, then points to that address.
For example, the name can help you find a home VPN or a server you manage. DuckDNS does not provide the server software, a VPN tunnel or a public IP address from your internet provider. It is also different from choosing a public DNS resolver address in your router’s network settings.
DuckDNS login and hostname setup
- Open duckdns.org and choose one of the sign-in options currently shown. If you already have a hostname, sign in the same way and with the same account you used to create it.
- Choose an available name in your account and add it. Write down the full hostname.
- Find your account token. It lets your updater change the address linked to your name. Keep it private, like a password.
- Choose a method from the official installation instructions: a router that supports it, or a computer or server that can run the updater.
- Run one update and check the reply. Then follow the instructions to keep it updating regularly.
If you run the updater on a computer, that computer needs to be on when the update is due. Your router also needs to support DuckDNS or its update format. Having a DDNS option in the router’s menu doesn’t mean DuckDNS will work with it.
Before following a router guide, check your router’s model and hardware version. The menus and supported services can change from one router or software version to another.
What does the DuckDNS token do?
The update instructions requires a subdomain and account token. Here’s an example of an IPv4 update. Fill in your subdomain and token on your own device. The full URL includes your secret token, so don’t share it in screenshots, posts or public logs:
https://www.duckdns.org/update?domains=YOUR_SUBDOMAIN&token=YOUR_TOKEN&ip=Use only the subdomain in domains, without .duckdns.org. Leaving ip blank lets the service detect IPv4. A normal response is OK or KO; the optional verbose setting gives a more detailed reply. DuckDNS can’t detect your IPv6 address this way. Follow its instructions to set IPv6 or both address records.
If you have shared your token by mistake, the DuckDNS FAQ explains how to create a new one in your account menu. Put the new token in every updater you use. Otherwise, they will keep trying to update with the old token.
Why does the name work, but the server won’t connect?
| Symptom | What to check | Next step |
|---|---|---|
| Update returns KO | Your subdomain, token and the update URL | Check your settings against the update instructions. |
| Hostname points to an old address | Whether the updater is using the right internet connection | Check when the last update ran, what it said and which address is saved. |
| Correct address, failed connection | Whether the server is running, plus its protocol, port and firewall settings | Try connecting from inside your home first. Then check the server’s instructions for connecting from outside. |
| Router has a private WAN address or CGNAT | Whether your internet provider lets outside devices reach your connection | Ask your provider about a public IP address, or choose a remote-access service that supports your setup. |
| Works inside the home but not outside | Whether you tested from another network | Try another network and write down the error message. |
ASUS‘s DDNS support guide explains why outside access needs a public IP address and can be blocked by private addressing or CGNAT. Updating your DuckDNS name doesn’t get around that limit. Don’t open your router’s settings page to the internet or open extra ports just to test the name.
Does DuckDNS make file transfers secure?
Security also depends on the service you connect to. If your goal is file transfer, our guide to FTP, FTPS and SFTP on Windows explains the differences between those protocols. Using a DuckDNS name doesn’t encrypt your file transfers.
Reviewed October 13, 2026, using DuckDNS and router support guides. The settings and available options depend on your device.
Frequently asked questions
Does DuckDNS give me a public IP address?
No. It updates DNS records; your internet provider controls the connection’s addressing.
Does an OK update response prove my server is reachable?
No. It confirms the DNS update request, not the server, port, firewall or routing.
Can it automatically detect IPv6 through the blank ip parameter?
The documented automatic address detection is for IPv4. Follow the API instructions to supply IPv6.
Can I share my update URL?
A real update URL contains your account token. Keep it private and replace a token that has been exposed.