Agent-run headless vs Contentful, Storyblok, Sanity and enterprise DXPs: an honest comparison

A headless CMS stores content and delivers it through APIs. It does not build the website. Optimizely says this plainly in its developer documentation: its CMS (SaaS) is a headless system, so you must develop and host the front-end application separately. Contentful describes its Content Delivery API as returning content as JSON through a globally distributed CDN. Sitecore provides a Content SDK with a Next.js starter template for the front end.

That is the part most budgets underestimate. The licence buys an editing interface, a content store and an API. The page templates, metadata, structured data, accessibility fixes, tracking and experiments are still a project, and after launch they are still a team.

This article is part of a series. Our pillar explains why most companies can run enterprise headless without a DXP; here we compare the options one by one, using only what each vendor publishes on its own website.

Prices below are only those published on each vendor’s pricing page on November 9, 2026. Where a vendor does not publish a price, we write contact sales. Enterprise tiers, the ones most large companies end up on, are custom-priced everywhere.

The third column is the one that matters. Every row except the first still needs front-end developers, someone who owns SEO and accessibility, and someone who owns tracking. A licence does not remove those jobs; it adds a contract next to them.

The second half of the comparison is where a website wins or loses search and AI visibility, and the deciding factor is the front end, not the content store. Frameworks such as Next.js, Astro, Nuxt and SvelteKit give you static generation or server rendering so crawlers receive complete HTML, metadata and canonicals at build time, structured data generated from content, sitemaps and llms.txt generated by code, and delivery from the edge. Most platforms leave all of that to the front end you build.

So the platform choice changes less for search than vendor pages suggest. On a Contentful, Sanity or Storyblok build, your team still decides how pages render, what schema they carry and which crawlers robots.txt admits. On a Sitecore, Optimizely or AEM build, the suite offers more features, but the rendered HTML is still only as good as the implementation partner. In the agent-run model, the SEO and GEO agent checks those properties on every pull request, whichever content source sits behind the pages.

We show what this looks like on a real site, with the screenshots, in how we scored 100 on PageSpeed Insights.

We recommend a commercial platform in these situations, and we say so in scoping calls. The agent-run model is not the answer to every brief.

• Dozens of non-technical editors publish every day and need visual, drag-and-drop editing with roles and scheduled publishing.
• Localization runs through translation vendors and connectors across many markets, with workflow and approvals per locale.
• Personalization at scale is a hard requirement, with audiences fed from a CDP and a vendor SLA behind it.
• A multi-brand portfolio shares one content hub across many sites and apps, not only the marketing site.
• Your company already owns a licence, has a trained team and a multi-year contract; replacing it would cost more than it saves.
• Data residency rules require a named region in the contract. Storyblok, for example, says customers can choose a hosting region, lists AWS data centers in North America (US and Canada), Europe (Germany) and Australia, offers Preferred Data Centers on its Elite plan and states it is self-certified under the EU-U.S. Data Privacy Framework.

Storyblok GmbH is based in Linz, Austria, which is one reason many European enterprises put it on their shortlist. If EU hosting is a requirement, confirm the region and the data processing terms in writing; a pricing page is not a contract.

Even when a platform wins, the agent-run model still applies to everything around it. The CMS becomes the place editors write; agents build and check the front end, the schema, the accessibility and the tracking.

Most B2B marketing sites publish a few pages a week, are edited by a small team and are judged on pipeline, search visibility and AI visibility. For that profile the expensive part is not storing content. It is the ongoing work around it: building templates, writing to a brief, checking claims, fixing accessibility, keeping pages fast, testing offers and making sure tracking still fires after every release.

A tool gives you a place to do that work. A function does the work. In the agent-run model each job has its own agent: content, SEO, GEO, accessibility, design QA, performance, experimentation and tracking QA. Each agent opens a pull request, a review board of other agents checks it, and people are only notified when they need to check or approve something. We describe the roles, gates and notifications in the AI agent web team operating model.

The savings come from three places. Licence: Vendr reports median contracts of $54,173 a year for Contentful and $81,447 for Optimizely, before any implementation work. Time: changes no longer wait in a developer or partner queue. Headcount: fewer specialist roles to hire, because their routine work moves to agents. We do not put a total percentage on it, because it depends on your current stack and team; we work it out per company.

PlanConversion does not sell a CMS, a DXP or a testing platform. We build the agent-run function on your stack: the framework and hosting, the agents and their rules, the review board, the approval gates and the notifications, connected to your CRM so reports show pipeline rather than page views. It is delivered through our website development service.

Experiments are part of the same function. Agents propose hypotheses, build variants at the edge and read results against the CRM, which is how we run A/B testing without an experimentation platform.

The testing discipline is the same as in our conversion rate optimization work, applied by agents and decided by people.

Search and AI visibility are designed in from the first build, with the schema, crawler rules and answer-first pages that generative engine optimization depends on.

This is how we built and run our own site. If you want the same results, talk to our team and we will come back with a full solution for your stack.