Decision
Subdomain vs dedicated domain for short links
Both work on every shortener that supports custom domains. They differ in cost, DNS mechanics, how much trust they inherit and how they read in print. This entry sets the two side by side.
The two options compared
| Factor | Subdomain (go.example.com) | Dedicated domain (exa.mp) |
|---|---|---|
| Cost | $0 | Registration and yearly renewal |
| DNS record | One CNAME | A record or ALIAS at the apex, plus www handling |
| Trust inherited | Your main domain's history | None at first; builds over time |
| Length | Main domain plus a label | As short as you can register |
| Print and voice | Fine for screens, long for print | Built for print and speech |
| Portability | Point the CNAME at a new vendor | Point the A record at a new vendor |
| Risk | None beyond your main domain | Expiry or registry issues break all links |
Mechanics are the same on every shortener in this comparison; only the DNS record type differs.
Trust and filtering
Email gateways, chat apps and ad platforms score links partly by domain reputation. A subdomain shares the reputation of its parent, so go.example.com is treated roughly as example.com is. A newly registered dedicated domain starts with no history. That is not a penalty, but it means the first weeks of links from it may be scrutinised more closely by some filters, and a burst of thousands of links on day one looks like exactly what abusers do. Warm a new short domain up with normal volume.
DNS differences that bite
A subdomain is a CNAME and that is the end of it. A dedicated domain's root cannot be a CNAME, so you need an A record with an IP the vendor publishes, or your DNS host's ALIAS or flattening feature. You also need to decide what www.exa.mp does, since some people add it by habit; redirect it to the apex or to your main site. Finally, if the dedicated domain is proxied through a CDN, make sure the proxy is not intercepting the certificate challenge; the troubleshooting entry covers that case.
A rule that settles it
Write the longest link you expect to publish in both forms. If the subdomain version fits comfortably where the link will appear, a tweet, an email footer, a slide, use the subdomain. If it will be on a poster, a product box, a podcast script or a radio spot, buy the dedicated domain. Many companies end up with both: a subdomain for digital channels and a dedicated domain for print, both pointed at the same shortener. Short.io's five free domains and ReSlug's ten on Pro make that cheap to run.
Questions & answers
Can I use go.mycompany.com as a short domain?
Yes. Add a CNAME record for go pointing at the target your shortener gives you. It works on the free plans of ReSlug, Short.io, Dub, Cuttly and Linkly.
Does a subdomain hurt my main website's SEO?
No. The short domain only redirects; it hosts no content that competes with your site, and redirects on a subdomain do not affect the parent's rankings.
Can I run both a subdomain and a dedicated domain?
Yes, on any plan that allows two or more domains: Short.io free, Dub free, ReSlug Pro, Rebrandly Essentials and above.
Sources for this entry
- ReSlug pricing reslug.com/pricing
- Short.io pricing short.io/pricing
- Dub pricing dub.co/pricing/links
Checked 8 November 2026. Vendor pages change; the date is the claim.
Cite this entry
Best Custom Domain URL Shortener. "Subdomain vs dedicated domain for short links". Reviewed 8 November 2026. https://bestcustomdomainurlshortener.com/subdomain-vs-dedicated-domain/