Setting Up Custom Domains

Short links that use a generic domain look impersonal and can feel untrustworthy to the people clicking them. When you use your own domain — for example, go.yourcompany.com — every link becomes a brand touchpoint. Studies consistently show that branded short links receive higher click-through rates because recipients can verify the source at a glance.

Custom domains also give you full control over your link namespace. If you ever move away from MASK, your domain and all of its links stay with you. There is no vendor lock-in.

Before you begin, make sure you have the following ready:

• A registered domain name that you own. You can use a root domain (e.g., links.co) or a subdomain (e.g., go.acme.com).
• Access to your domain's DNS settings. This is usually available through your domain registrar (Namecheap, GoDaddy, Cloudflare, etc.).
• A MASK workspace on a plan that supports custom domains. Check your plan details in Settings → Billing.

Navigate to your workspace Settings → Domains and click "Add Domain." Enter the full domain or subdomain you want to use (for example, go.acme.com). MASK will validate the format and check that the domain is not already registered on another workspace.

After adding the domain you will see a status of "Pending" along with the DNS records you need to create. Keep this page open — you will need the values shown here in the next step.

Log in to your DNS provider and create the records that MASK displayed in the previous step. For most setups you will need a single CNAME record:

If you are using a root domain (apex domain without a subdomain), some DNS providers do not support CNAME records at the root. In that case, look for an "ALIAS" or "ANAME" record type, or use a provider like Cloudflare that supports CNAME flattening at the root.

DNS propagation typically takes between 5 minutes and 48 hours, though most changes take effect within 30 minutes. You can use a tool like dig go.acme.com CNAME to check whether your record has propagated.

Once you have created the DNS record, return to Settings → Domains in MASK and click "Verify." MASK will perform a DNS lookup to confirm that your CNAME points to the correct destination.

If verification succeeds, the domain status will change to "Active" and you can immediately start creating links on it. If verification fails, double-check that the DNS record values match exactly — trailing dots, typos in the target hostname, and conflicting A records are the most common causes of failure.

MASK will also periodically re-verify your domain in the background. If DNS records are removed or changed, the domain status will revert to "Pending" and links on that domain will stop resolving until the issue is fixed.

MASK automatically provisions a free TLS/SSL certificate for every verified custom domain using Let's Encrypt. No manual action is required on your part. Certificate provisioning begins as soon as DNS verification succeeds and usually completes within a few minutes.

All short links served on your custom domain will use HTTPS by default. HTTP requests are automatically redirected to HTTPS. If you are using Cloudflare as a proxy in front of MASK, set the SSL mode to "Full (Strict)" to avoid redirect loops.

Domain stuck on "Pending": DNS propagation can take up to 48 hours in rare cases. Verify that your CNAME record exists using a DNS lookup tool and that there are no conflicting A records on the same hostname.

ERR_TOO_MANY_REDIRECTS in browser: This usually happens when Cloudflare is set to "Flexible" SSL mode. Switch it to "Full" or "Full (Strict)."

Certificate not provisioning: Make sure your DNS provider is not blocking the ACME HTTP-01 challenge. If you are proxying through Cloudflare, temporarily set the record to "DNS only" (gray cloud) until the certificate is issued, then switch back to proxied.

"Domain already in use" error: Each domain can only be linked to one MASK workspace. If you previously added it to a different workspace, remove it there first, or contact support if you no longer have access.