"Custom" is doing less work in that phrase than most people assume. It doesn't mean a domain built specifically for you, it means a domain you supply yourself to a hosted service, in place of the free address that service hands out by default. That domain can be a brand new .com you just registered, or it can be a subdomain carved off a domain you already own for something else entirely. Both count. Neither requires the other.
Custom domain vs subdomain: the confusion, cleared up
People tend to treat "custom domain" and "subdomain" as opposites, and they aren't. A subdomain like go.yourbrand.com becomes a custom domain the moment you point it at a tool instead of leaving it unused. The real opposite of a custom domain isn't a subdomain, it's the platform's own shared domain, whatever address your page or link lives on by default: raydar.bio, bit.ly, linktr.ee, or similar.
There are two real setups worth distinguishing. A root or apex domain, yourbrand.com with nothing in front of it, pointed entirely at one service. Or a subdomain, go.yourbrand.com or link.yourbrand.com, carved out while the root domain keeps doing something else, most often running your main website. Most people setting up a branded link or a bio page want the second option, since it lets a website live at the root and a link tool live on a subdomain without the two fighting over the same address. The DNS mechanics of getting either one live are covered separately in how to point a domain with DNS.
What changes when you add one
The difference isn't cosmetic once you look past the address bar. Setup cost varies. So does who ends up owning the domain's reputation, and how much ongoing commitment each option demands.
| Setup | What it looks like | Setup cost | Who owns the domain's reputation |
|---|---|---|---|
| Shared platform address | raydar.bio/yourname or similarly branded shared path | Free, live instantly | The platform, shared across every customer using that same domain |
| Custom subdomain | go.yourbrand.com pointed at the same tool | A domain you likely already own, a few minutes of DNS work, usually a paid plan on the tool's side | Yours, though it starts with no history of its own either |
| Full new domain and site | A standalone site built from scratch under a brand new domain | Domain registration plus hosting and build time | Entirely yours, from a blank slate |
Do you actually need one
Not always, and pretending otherwise is how a lot of custom domain advice loses its credibility. If you're testing an idea, sharing a link occasionally, or not yet posting under a consistent name, a shared platform address does the job with zero setup. The case for a custom domain gets stronger once your links are public and repeated: printed on packaging, on business cards, dropped in a bio that strangers screenshot and reshare. At that point a domain people recognize on sight reads as more deliberate than a shared one, and it's the same reason "branded domain" gets used almost interchangeably with "custom domain" in marketing contexts. Both terms describe the same thing: an address that carries your name instead of a vendor's.
The trust trade-off nobody quantifies honestly
Most "get a custom domain" advice skips this part entirely. A brand new custom domain doesn't inherit any reputation the moment you set it up, good or bad. That cuts both ways. You escape whatever baggage a shared platform domain might carry from other customers on it, but you also start from zero trust of your own, and some spam filters and security tools treat a domain with no history as more worth checking than one with years of clean volume behind it. A custom domain is a genuine upgrade over time. It is not an instant one, and anyone promising otherwise is skipping the part where reputation gets built rather than bought. The full mechanism behind that, including a rewriting behavior most filters rely on, is covered in why links get blocked by spam filters.
How a custom domain actually connects
Underneath the branding, a custom domain works by pointing a DNS record, usually a CNAME on a subdomain, at the platform serving your content. What happens after that record resolves is where platforms genuinely differ. Some simply redirect your domain to their own, which means the address bar shows your name for a moment and then reveals theirs anyway. Others run your page through a reverse proxy, serving the content while your domain stays in the address bar for the entire visit, which is real infrastructure on the platform's side rather than a cosmetic trick. Raydar's first paid plan gives you the reverse proxy version when you connect a domain, and the full setup walkthrough, including a certificate trap that catches almost everyone who skips straight to the DNS step, is covered in how to use a custom domain for short links.
Mistakes worth avoiding before you commit
Buying a second, unrelated domain purely for a bio link is rarely necessary and adds an ongoing renewal cost for no real benefit, when a subdomain of a domain you already control does the same job. Picking a subdomain label that's longer or harder to say than the brand name itself is another one, since it competes with the exact thing you were trying to make more memorable. And treating a custom domain as a one-time setup rather than something with an ongoing DNS dependency causes the quiet failures: a domain that expires because nobody moved the renewal reminder, or a DNS provider that gets swapped for a cheaper one without the old records being copied across first. None of these are hard problems. They're just the ones that don't show up until months after the initial setup, when the person who configured it has moved on to something else.