WordPress to Sanity migration cost: does it actually pay back?

The question I hear most often from founders and marketing directors isn't 'how does Sanity work?' — it's 'what will this actually cost, and will we ever see that money back?' That's the right question. WordPress to Sanity migration cost isn't just the development invoice; it's the full before-and-after picture across hosting, plugins, editorial time, and organic traffic. Let me walk through each piece honestly.

What a migration typically costs to build

Most WordPress-to-Sanity projects I scope fall into one of two buckets.

Smaller content sites — ten to thirty page types, a blog, no complex integrations — run between £6,000 and £14,000 for design-to-deployment work. That assumes the design system either exists already or is being simplified during the migration, and that the editorial team is small (one to five people).

Mid-size marketing or product sites — fifty-plus page types, multi-author workflows, localisation, custom landing-page tooling — land between £18,000 and £40,000. The wide range is real: it depends on how many legacy page layouts need rebuilding and how much content needs manual restructuring rather than automated export.

Those numbers assume a freelance senior developer or a small specialist agency. A large agency will charge more; an offshore team with no Sanity production experience will charge less but often costs more in rework.

The migration itself — exporting WordPress content, mapping it to new Sanity schemas, running import scripts, and validating everything — typically adds £1,500 to £4,000 on top of the build cost depending on post volume and how many custom fields the old site accumulated over the years.

Where the money comes back

Plugin licence savings. A typical WordPress site that's been running for three or more years carries between £800 and £3,000 per year in plugin licences: SEO tools, form builders, page builders, caching plugins, security scanners, backup services, and whatever the previous agency installed and never removed. Most of those jobs are handled differently in a Next.js + Sanity setup — SEO metadata lives in code, forms go through a dedicated service like a simple API route, caching is handled by the CDN and ISR. Realistically, expect to save £600 to £2,000 per year on licences alone.

Hosting savings. Managed WordPress hosting for a site doing 50,000 to 200,000 monthly visits runs £80 to £400 per month, often more if the previous team over-provisioned to handle traffic spikes. Vercel's Pro plan plus Sanity's Growth plan together sit closer to £60 to £130 per month for the same traffic profile. That's a saving of £600 to £3,000 per year, and it scales better — a traffic spike doesn't require an emergency upgrade call with a host.

Editorial efficiency. This one is harder to put a number on but often drives the decision more than hosting costs. WordPress's Gutenberg editor carries years of accumulated complexity, and most content teams I talk to have worked around it rather than with it — duplicating pages instead of using templates, avoiding blocks that behave unpredictably, waiting for a developer every time a new content type is needed. Sanity Studio is purpose-built for structured content. Editors get document-level previews, real-time co-editing, and a schema that matches exactly what they publish — no more orphaned fields from a plugin installed in 2019. Teams I've worked with report saving two to four hours per week in editorial overhead per person. At a conservative £30 per hour, that's £3,000 to £6,000 per year for a two-person team.

Performance and SEO uplift. This is the variable that can dwarf everything else, or amount to nothing, depending on your current baseline. If your WordPress site scores in the 40s on Core Web Vitals and you're competing for commercial search terms, moving to a statically generated or edge-cached Next.js front end typically moves LCP from 4–6 seconds to under 1.5 seconds. Google's ranking signals respond to that. I've seen clients recover from a position-eight plateau to page-one positions within three months of launch — that's meaningful revenue that wouldn't show up in a simple cost comparison. If your site already scores well and ranks well, the SEO case is weaker.

Rough payback calculation

Taking the conservative end: £800 licence savings + £600 hosting savings + £3,000 editorial time savings = £4,400 per year. Against a £12,000 migration project, that's a 2.7-year payback before counting any SEO uplift. If editorial savings are at the higher end and performance improvements move the needle on organic traffic, payback falls inside eighteen months.

Against a £30,000 project, the maths requires either a larger editorial team, real SEO gains, or both.

When the migration doesn't pay back

I'll be direct about this because I turn down projects more often than founders expect.

Low-traffic informational sites — under 5,000 monthly visits, no commercial intent — have no realistic path to SEO-driven ROI, and the licence and hosting savings rarely justify a £10,000+ build.

Happy editorial teams are underrated. If your team knows Gutenberg, has built a workflow around it, and isn't complaining about publishing friction, you're not fixing a real problem. Migrating will create a training and transition cost that erases short-term savings.

No upcoming rebrand or redesign. The cleanest migrations happen when a visual refresh is already planned. Migrating content without touching the design means you're paying for a backend swap the user never sees. The ROI case is much weaker.

Sites with heavily WordPress-specific functionality — WooCommerce, membership plugins, LearnDash — carry significant rebuild cost. It's not impossible, but the project scope balloons and payback extends accordingly.

How to decide

Before agreeing to a scope or signing anything, ask for an audit. A good developer should be able to spend three to five hours reviewing your current plugin list, hosting invoice, editorial workflow pain points, and traffic data, then give you a rough payback estimate. If they can't or won't do that, they're not thinking about your business — they're thinking about billable hours.

The migration only makes sense if the numbers work or the editorial team is genuinely blocked. When both are true, it's one of the highest-ROI technical investments a content business can make.