WordPress to Headless: When to Migrate and How to Do It

WordPress powers a lot of B2B sites. It also slows them down. Themes drag in unused CSS and plugins. PHP renders every request. The admin is a public attack surface. Headless can fix that — if you treat it as a migration, not a redesign that forgets old URLs.

This is the path off WordPress. If you’re still deciding whether a headless CMS belongs in B2B at all, read Headless CMS for B2B first.

When to Migrate

Move when the CMS is the constraint, not when you’re bored of the theme.

• Speed — LCP sits over 2.5s on key pages after image and hosting work. The theme and plugin stack is the leftover weight.
• Custom flows — Multi-step quotes, gated tools, or industry finders that the theme can’t do without more plugins.
• Editorial vs. engineering — Marketing needs structured fields (services, industries, proof). Gutenberg blocks have become a pile of one-off layouts.
• Security and ops — Constant plugin patches, login spam, or a host that exists only to keep PHP alive.

Stay on WordPress when the site is small, already fast, and the team is productive in wp-admin. Headless is a trade: more frontend control, more implementation work.

Two destination patterns:

1. WordPress as headless CMS — Keep wp-admin. New frontend (Astro or Next.js) fetches via the REST API or WPGraphQL. Good when editors won’t leave WordPress.
2. Leave WordPress — Export content into Sanity, Contentful, or a git-based CMS. Better long-term if you’re already rewriting templates.

Pick this in discovery. It changes the export and the training plan.

What to Preserve

Migrations fail in Search Console, not in the design review.

URLs

301 every old URL that has traffic, links, or rankings. /services/web-design/ to the new path. Blog permalinks especially. WordPress defaults (/2023/04/post-name/ or ?p=47) need a map, not hope.

Export a full URL list from the sitemap, Search Console, and analytics. Diff it against the new sitemap. Unmapped URLs get a decision: redirect to the closest equivalent, or 410 if the content is gone on purpose.

Content

Migrate pages, posts, media, and metadata. Keep title tags if they’re good. Don’t “start fresh” and leave five years of posts in a ZIP.

Download the uploads library. Re-host or point the CDN at those files. Broken images are a silent ranking hit.

Structure

Categories, tags, author, and custom fields. If you had industry and service taxonomies, they become fields in the new content model — or they become URL prefixes. Decide before you import or you’ll flatten everything into a generic “page.”

The Process

1. Content export

Use the REST API, WPGraphQL, or a database export. You want structured JSON, not a WXR file you paste by hand. Inventory:

• Post types (page, post, case study, service)
• Fields per type
• URL for each item
• Featured image and attachments

2. Content model on the new side

Mirror what you have, then tighten. A service entry needs: name, slug, problem, deliverables, FAQs, related industries. Don’t recreate 40 ACF layouts. That’s how you rebuild WordPress inside Sanity.

3. New frontend

Astro if the site is mostly static. Next.js if you need server logic, auth, or frequent rebuilds. Either can read WordPress as a headless source or a new CMS. See Next.js vs. Astro for the split.

Build templates against the new model. Import a slice of content first — homepage, two services, ten posts — and prove the render path.

4. Redirect map

Spreadsheet: old path → new path → 301. Implement at the host or in the app. Test with a crawler before DNS flips. Redirects and analytics go live the same week as the cutover, not after.

5. Launch

Freeze WordPress 24–48 hours out, or run a final sync. Flip DNS. Confirm SSL. Spot-check the 20 highest-traffic URLs. Watch Search Console 404s for two weeks. Fix misses the same day.

Don’t launch with “we’ll add redirects later.” Later is when organic leads drop and nobody can prove why.

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We’ve migrated WordPress sites onto modern stacks without orphaning their URLs. See the web design and development process or plan your migration.