Headless WordPress Migration: Keep wp-admin, Ditch PHP

Headless WordPress migration keeps your existing wp-admin installation as the content backend and replaces the PHP theme layer with a decoupled frontend built in Next.js or Astro. We build these for marketing directors and technical leads running a WordPress site that's outgrown its performance ceiling -- plugin conflicts, page-builder bloat, PHP render delays -- but whose editorial team isn't moving off wp-admin any time soon, and shouldn't have to.

Here's what actually changes: the delivery layer. Nothing else. Editors keep the same login, the same block editor, the same media library and custom fields. Their daily workflow doesn't shift at all. What disappears is the theme's PHP execution on every request. Instead, WPGraphQL or the REST API feeds a Next.js or Astro frontend that's built and served from a CDN edge network. We've watched TTFB drop from the 800ms-2,000ms range typical of plugin-heavy WordPress installs to under 50ms, with Lighthouse scores moving from the 35-65 range into the 90-100 band. A typical migration for a content-focused site with a defined data model runs 2-3 weeks: API wiring, frontend build, content mapping, DNS cutover. Sites with heavier custom field structures, multilingual content, or e-commerce integrations take longer -- no way around that. Fixed-fee cost sits in the $15K-$60K band depending on template count, integration depth and content model complexity, and ongoing frontend costs drop once plugins are out of the visitor-facing stack for good.

Who this is for -- and when it's the wrong call

This move makes sense if you recognize the pattern: a plugin update ships on a Tuesday, your homepage layout shifts on Wednesday, and by Thursday someone's asking why the site is slow on mobile. If your Lighthouse score sits in the 40s or 50s and your content team has years of posts, custom fields, and taxonomies baked into WordPress, a headless migration gets you performance back without forcing a content migration project on top of it.

It's the wrong call in a few specific situations. If your site gets under a few thousand visits a month and nobody's complaining about speed, a well-maintained traditional WordPress install is still fine. Don't pay to fix a problem you don't have. If you're starting from zero with no legacy content, a purpose-built headless CMS usually gives you a cleaner content model than bolting a frontend onto WordPress -- we lay out that trade-off in WordPress vs headless CMS. And if WooCommerce checkout and subscriptions are your core business, headless WordPress handles the catalog fine, but the checkout flow needs real scoping before anyone commits to a date.

How we do it

We don't touch your content model on day one. The work happens in three phases:

• Audit and API layer (week 1). We map every custom field, taxonomy, form integration and plugin dependency the frontend needs to read from. We stand up WPGraphQL or the REST API, depending on your existing plugin ecosystem, and confirm every content type -- posts, pages, ACF fields, custom post types -- resolves cleanly before we build anything on top of it.
• Frontend build (weeks 1-2, overlapping). We build the new frontend in Next.js or Astro with TypeScript and Tailwind CSS, matching your existing design or improving it where the old theme was holding you back. We build components against real content pulled from the API, not placeholder data, so what you see in staging is what goes live.
• Cutover (final days). Redirects, DNS changes, and a final content sync happen together, with the WordPress admin staying live throughout so editors never lose access. We handle 301 redirects carefully here -- a migration that tanks your search rankings because of broken redirects isn't a win, no matter how fast the new site loads.

What you get at the end: a Next.js or Astro codebase deployed to a CDN edge network, a documented API layer your future developers can extend, and a wp-admin instance that looks and works exactly like it did before -- just decoupled from what visitors actually load. No retraining sprint, no new login, no workflow documentation to write for your editorial team.

For teams who want the performance win now but aren't ready to commit to a full platform change, this bridge approach lets you decouple the frontend today and revisit the CMS later without redoing the work twice.

What we've shipped

SleepDr.com, a sleep medicine practice, moved from WordPress to Next.js 15 with Payload CMS and Supabase. The rebuild included a HIPAA-safe architecture -- patient intake handled through HIPAA-compliant Jotform rather than storing PHI on our servers -- medical schema markup, 20 city landing pages, and four-language support. Lighthouse went from 35 to 94. It's a verified 5.0 Clutch review. Full detail in the SleepDr case study.

bdManagedIT, a managed IT provider serving Central Georgia, rebuilt from WordPress onto Astro with Sanity and Netlify. The result hit 95+ PageSpeed with zero-JS static pages across service, industry and location pages, plus HIPAA, PCI-DSS, CJIS and SOX compliance guides, a HubSpot CRM integration, and full AI-search schema. Read the bdManagedIT case study.

Both projects kept the client's editorial workflow intact while replacing the rendering layer entirely. That's the whole point of this migration path -- not a rebuild for its own sake.

Sources

The performance claims here track with Google's Core Web Vitals guidance and the underlying web.dev vitals documentation. Our redirect handling during cutover follows Google's 301 redirect guidance to protect existing search rankings, and the API layer approach is documented in the WPGraphQL docs.

If your WordPress site is failing Core Web Vitals and your editorial team can't afford downtime or retraining, this is a narrow, well-understood project with a fixed scope. Get a fixed-fee quote at /contact/.