Custom Domain for Documentation

docs.yourcompany.com looks more professional than docsbook.io/yourorg/yourrepo. It also matters for SEO, trust, and the "is this a real product" first impression. This is how to set it up correctly.

TL;DR#

1. Decide subdomain (docs.yourcompany.com) vs subdirectory (yourcompany.com/docs/)
2. Add a CNAME or A record in DNS pointing to your docs host
3. Wait for SSL to provision (usually under 5 minutes)
4. Set up redirects from any prior URL
5. Update internal links and external mentions

Subdomain vs subdirectory#

The SEO debate is real. Both work in 2026, but they have different tradeoffs.

For most teams, the subdomain is easier and the SEO difference is small. Only go subdirectory if your main site is on a platform that supports reverse-proxying docs cleanly.

Setting up the subdomain (Docsbook example)#

Three steps:

1. In Docsbook dashboard#

• Open your workspace settings
• Settings → Domain
• Enter docs.yourcompany.com
• Click Save

The dashboard shows the DNS records you need to add.

2. In your DNS provider#

Add a CNAME record:

Type:  CNAME
Name:  docs
Value: cname.vercel-dns.com
TTL:   300 (or default)

If your DNS provider doesn't support CNAME at the root (Cloudflare's flattening or similar), use the A record alternative your platform provides.

3. SSL#

SSL is automatic. Docsbook (via Vercel) provisions a Let's Encrypt cert within 5 minutes. You will see "Active" status in the dashboard.

Total time: usually 5–15 minutes including DNS propagation.

When SSL takes longer#

If SSL stays "Pending" after 30 minutes:

• Check that DNS has propagated globally: dig docs.yourcompany.com should resolve to the CNAME target
• Remove any CAA records that block Let's Encrypt
• Check that your domain isn't already serving HTTPS from another provider

Redirects#

If you previously hosted docs at a different URL, set up 301 redirects to preserve SEO.

From a docs subdirectory to the new subdomain#

yourcompany.com/docs/* → docs.yourcompany.com/* (301)

Most platforms support this via redirect rules.

From GitBook v-paths to Docsbook#

GitBook URLs typically have /v/1.0/ patterns:

docs.yourcompany.com/v/1.0/api/auth → docs.yourcompany.com/api/auth (301)

If you use Cloudflare in front of your domain, you can do this with a single page rule. See migrating from GitBook to Docsbook.

From Docusaurus prefix to root#

Docusaurus often uses /docs/intro paths. If you flatten to root:

docs.yourcompany.com/docs/* → docs.yourcompany.com/* (301)

See migrating from Docusaurus to Docsbook.

SEO considerations#

Three things to verify after the cutover:

Search Console#

Add the new domain to Google Search Console. Submit the sitemap (Docsbook auto-generates /sitemap.xml). Watch the indexing report for 4–6 weeks.

Canonical tags#

If you keep the old URL live as a fallback for any reason, set canonical tags on the old URL pointing to the new one. Better: just 301-redirect.

llms.txt propagation#

When you move domain, AI agents need to re-discover your llms.txt. They usually do within a few crawls. Verify:

curl https://docs.yourcompany.com/llms.txt | head -10

See the complete llms.txt guide.

What changes for users#

• Bookmarks to old URLs: covered by redirects
• Saved support replies: update them
• Internal product links: update them
• External backlinks: stay (the 301 transfers authority)

The user-visible experience should not change beyond the URL.

Custom domain support by platform#

For managed docs platforms, custom domain is a paid feature. The Docsbook lifetime PRO at $150 is the cheapest option in the comparable set.

Common mistakes#

• Pointing the apex domain at a CNAME — most DNS providers do not allow this; use subdomain (docs.) or a flattened A record
• Forgetting to redirect — old URLs 404 → SEO drops → loss of authority
• HTTPS not enforced — some platforms serve HTTP and HTTPS both; force redirect to HTTPS
• Multiple docs subdomains — only one CNAME at a time, drop old ones first

Related reading#

• Migrating from GitBook to Docsbook
• Migrating from Docusaurus to Docsbook
• Documentation SEO guide

Docsbook supports docs.yourcompany.com with free SSL on PRO ($150 lifetime). See pricing →