Subdirectory vs Subdomain for Blogs: SEO Data You Need
Most blogs still live on subdomains, even though subdirectories usually compound authority faster. This guide shows the 2025 data, when subdomains still make sense, and how to move to /blog safely with a reverse proxy. You’ll see real benchmarks, internal linking patterns that Google rewards, and a practical migration checklist you can run this quarter.
Table of Contents
- Why this debate still matters
- What the 2025 data shows
- SEO gains from moving to a subdirectory
- When a subdomain is still the right call
- Reverse-proxy shortcut to serve /blog
- Low-risk migration checklist
- What to track after launch
- Related posts
Why this debate still matters
Marketers fight for compounding domain authority. Splitting content across hosts slows ranking and weakens brand SERPs. Subdirectories keep all signals on the root, accelerating keyword growth and conversions. In 2025, Google’s Helpful Content and core updates continue to reward tightly interlinked site structures; subdomains often look like separate sites, diluting that signal.
Quick definition
- Subdomain:
blog.example.com— separate host, separate crawl budget and authority signals. - Subdirectory:
example.com/blog— same host, shared authority, easier internal links and sitelinks.
Who should care
- Marketing teams chasing faster non-brand growth.
- Founders who want clean attribution from blog → product flows.
- SEO leads who need safer migrations with measurable upside.
What the 2025 data shows
- Industry crawls still show subdirectories winning in 7/10 comparable cases when technical hygiene is equal (source: Ahrefs, Moz).
- Freshness matters more post-HCU: subdirectories inherit root recrawl frequency faster, which means new posts get indexed in hours instead of days.
- Cannibalization risk is lower on
/blogbecause internal linking stays on one host and Google can consolidate query intent more cleanly. - Large sites that moved from subdomain to subdirectory often see 8–25% organic session lift within 60–120 days when redirects and canonicals are correct (internal benchmarks and public case studies).
- Internal link depth is shallower on subdirectories; this boosts crawl prioritization for evergreen posts and new launches.
SEO gains from moving to a subdirectory
- Link equity consolidation: every post strengthens the main domain.
- Cleaner analytics: one property for content + product funnels; no cross-domain session stitching.
- Rich results: sitelinks and jump links appear more often when content sits under one host with a clear ToC.
- Higher CTR: brand + non-brand blended SERPs often show more sitelinks when the blog is under
/blog. - Better internal linking: you can place 4–8 cross-links per post to product, docs, and related guides without cross-host penalties.
When a subdomain is still the right call
- Strict governance or legal separation (financial, regulated industries).
- Fully different product lines with distinct branding or teams.
- Heavy app traffic that must stay isolated from marketing content.
- Complex multi-language setups where ccTLDs or subfolders are already mapped per market (in this case, evaluate hreflang strategy carefully).
Reverse-proxy shortcut to serve /blog
Instead of rebuilding WordPress/Blogger, use a serverless, high-performance proxy to serve origin content at /blog:
- Keep plugins, themes, and CMS workflow.
- Edge cache static assets; short TTL for HTML to stay fresh.
- Origin shielding + WAF reduce attack surface.
- Zero-code: change DNS, keep origin untouched.
- BlogPath.io provides this out of the box with global POPs, uptime SLAs, and observability so you don’t maintain scripts.
Low-risk migration checklist
- Map URLs 1:1; keep slugs identical and avoid trailing slash changes.
- Set canonicals to
/blogversions; verify sitemap path and resubmit in Search Console. - Test logins, forms, search, and feeds through the proxy; exclude
/wp-adminand login endpoints from caching. - Keep DNS TTL low for rollback; prepare a maintenance page as a last resort.
- Add 4–8 internal links from existing high-traffic posts to the migrated
/blogURLs within 24 hours to accelerate reindexing. - Outbound links: keep 3–5 authoritative references (e.g., Google Search Central, Moz, Ahrefs) to reinforce trust.
What to track after launch
- Organic sessions (brand + non-brand), rankings for target keywords; compare 30/60/90-day windows.
- Core Web Vitals: TTFB/LCP should improve with edge caching; monitor INP as well.
- Crawl errors and 404 rate; fix quickly to avoid quality downgrades.
- Conversion rate and assisted conversions (blogs in subdirectories often lift both).
- Internal link coverage: ensure every new post links to 4–8 related assets and that pillar pages link back to this post.
- Engagement signals: time on page, scroll depth, and CTA clicks to product pages.
FAQ: fast answers for snippet wins
Do subdirectories always beat subdomains for SEO?
Not always, but in most marketing use cases they do. If governance or brand separation is required, subdomains may stay. Otherwise, /blog tends to win on authority consolidation and crawl priority.
How many internal links should each post add?
Aim for 4–8 internal links per post, mixing partial and exact-match anchors naturally. Add 2–3 backlinks from existing high-authority posts to this one within 24 hours of publishing.
Do I need to change my CMS?
No. A reverse proxy like BlogPath.io lets you keep WordPress/Blogger as-is and surface it at /blog with caching, WAF, and observability.
Will rankings drop during the move?
Expect minor volatility for 1–2 weeks. Good redirects, stable slugs, and internal links reduce risk. Keep DNS TTL low for rollback.