Best CMS Options for Agency Marketing Sites
What to pick when the client needs to update content without breaking things
I've built CMS-backed marketing sites in Webflow CMS (IronLife), Next.js with MDX, and headless setups. The right choice depends on how technical the content team is, how custom the design is, and how often the content changes. Here's the breakdown.
Design + CMS in one — best when the client wants to manage their own content
Webflow CMS is the right call when the client is non-technical and you want them to update blog posts, team members, or service pages without a developer. The visual editor means they won't break the layout. The limitation is the page count on lower plans and the learning curve for the builder itself. IronLife's site was built on Webflow CMS — the client manages all content independently.
Structured content with a customisable editing studio
Sanity is the right choice when you need structured content that drives a custom-built frontend. GROQ queries are powerful for complex content relationships. The Studio is customisable enough to match client workflows. The free tier is generous. The setup cost is higher than Webflow — budget an extra day for schema design and Studio configuration.
Enterprise headless CMS — established, well-documented, pricey
Contentful is mature and stable. The content model is flexible, the API is well-documented, and it integrates cleanly with Next.js. The pricing is aggressive for small teams once you need multiple locales or advanced content management. For agency work on well-funded clients, it's a safe choice. For lean startups, look at Sanity first.
Markdown files in the repo — best for developer-authored content
If the content authors are developers, MDX in the repo is the simplest CMS — no external service, no API, version-controlled, deploys with the site. This is what most developer blogs and documentation sites use. Falls apart when non-technical clients need to publish content without a Git workflow.
Non-technical clients who edit their own content: Webflow CMS. Custom frontend with structured content: Sanity. Enterprise budget with existing Contentful investment: Contentful. Developer-authored content only: MDX in the repo. The mistake is defaulting to headless when Webflow CMS would serve the client better — and defaulting to Webflow when the design requires a custom-built frontend.