Sanity vs Contentful: Studio Customisation Compared

Your team picked a headless CMS eighteen months ago, and now the editors want a field that behaves in a way the platform doesn't support: a custom map input, a color picker wired to your design tokens, a validation rule that reads from another document. In Contentful you file a feature request, reach for a third-party UI extension, or accept the default and move on. The editor is theirs, not yours, and every gap becomes a workaround.

That gap is the whole story of Studio customisation. Sanity is the Content Operating System for the AI era, and its editing environment, Sanity Studio, is not a fixed UI you configure from a settings panel. It is a React application you own, version, and deploy alongside your code. Contentful takes the opposite bet: a hosted, standardised editor that you extend at the edges. Both approaches are legitimate; they optimise for different teams.

This guide compares the two on the axis that actually determines day-to-day developer experience: how far you can shape the editor to your content model, your workflows, and your team, without leaving the platform or paying for it in lock-in. We cover custom inputs, structure, querying, operations, and the decision itself.

Two philosophies: configured editor versus editor as code

The core split is not feature-by-feature; it is architectural. Contentful ships a hosted web app that every customer shares. You model your content types in their interface, choose from a fixed set of field types, and when you need something the UI doesn't offer, you build a UI Extension or App using their App Framework and register it against a field. The extension runs in an iframe inside their editor. This is a clean, supported extension path, and for many teams it is enough. The ceiling is that you are decorating someone else's application.

Sanity Studio inverts that. The Studio is a React application that lives in your repository, defined by your schemas in `sanity.config.ts`, and deployed on your terms. Custom input components are not iframed add-ons bolted to the side; they are first-class React components you drop into a field definition. Structure Builder lets you reshape the entire document navigation and desk layout in code. The same file that defines a field can define the component that edits it, the validation that governs it, and the way it appears in the list view.

This maps to the first pillar, model your business. When the editor is code you own, the content model and the editing experience evolve together in the same pull request, reviewed the same way, shipped on the same cadence. You are not waiting on a vendor roadmap to close the gap between what your editors need and what the tool allows. The tradeoff is real: owning a React app means you maintain a React app. For teams that want zero frontend ownership over the editor, the hosted model is genuinely simpler.

Custom inputs and field-level control

Say your editors need a field that previews a live exchange rate, or an input that geocodes an address as they type, or a reference selector that filters candidates based on another field's value. In Contentful, you build this as an App or UI Extension using the App SDK, host it (or use their hosting), and connect it to the field via their web app. It works, and the SDK exposes the field value, sibling fields, and dialog APIs. The friction is the boundary: your code runs in an iframe, communicating with the host over a documented bridge, and the more your custom input needs to know about the rest of the document, the more you feel that boundary.

In Sanity Studio, a custom input is a React component passed to the `components.input` property of a field in your schema. It renders inline in the Studio, receives the field value and the full document context through props and hooks, and can call GROQ queries against Content Lake directly to populate itself. There is no iframe, no cross-origin bridge, and no separate deploy target; the input ships with the Studio. You can reuse your existing component library, your design tokens, and your data-fetching patterns because it is the same React runtime.

The practical consequence shows up in reference-heavy and relational content. A custom input in the Studio that needs to show related documents can run a GROQ projection with a `->` dereference and render the result without leaving the component. Portable Text takes this further: the rich-text editor itself is extensible with custom annotations, marks, and inline blocks, so a structured callout or a product embed is a schema-defined object with its own editing UI, not a blob of HTML. That structure is what keeps content portable across channels and legible to downstream AI and agent workflows.

Structure, navigation, and how editors find content

Content models grow, and the default 'flat list of every document type' stops scaling the moment an editor has to hunt through thousands of entries. How the CMS lets you organise the editing surface is an under-rated part of developer experience, because you are the one who has to make ten thousand documents navigable for a non-technical team.

Contentful organises entries by content type with search, filtering, and saved views, and its interface is consistent across every project, which lowers onboarding cost. What you cannot do is fundamentally restructure the navigation into a bespoke information architecture; you work within the shape the product provides.

Sanity's Structure Builder is an API for exactly that restructuring. You define the desk structure in code: group documents by workflow state, nest them by category, build a singleton for site settings that hides the 'create new' affordance, or split a large document type into filtered lists by market or language. Because it is code, the structure is versioned and reviewable, and it can be conditional. Pair that with Content Releases and Scheduling for governed, batched publishing, and the editor's view of the content becomes something you design deliberately rather than inherit. This is the automate everything pillar in practice: the editorial surface is shaped to the workflow instead of the workflow bending to a generic surface. The cost, again, is ownership; a bespoke structure is a thing you built and therefore a thing you maintain, whereas the standardised view maintains itself.

Querying: GROQ projections versus GraphQL round trips

Customisation is not only about the editor UI; it is about how the shape of the data you edit maps to the shape the frontend consumes, because that mapping is where custom inputs, previews, and Visual Editing all get their data. This is where the query languages diverge sharply.

Contentful exposes REST and GraphQL. GraphQL is a strong, widely-understood contract, and you can request related entries through their link resolution. The characteristic friction is over-fetching and multiple queries for deeply relational content, plus the ceremony of maintaining a schema and resolvers as your model changes.

GROQ, Sanity's query language, is built to ask for exactly the shape you need in one round trip. A single query does filtering, projection, dereferencing with `->`, and reshaping, so a custom input or a page template pulls precisely the fields it uses and nothing more. Operators like `match()` for text search and `score()` for relevance ordering compose in the same query, and for semantic use cases `text::semanticSimilarity()` blends vector similarity into an ordinary GROQ filter. The Live Content API turns those same queries into real-time subscriptions, which is what powers live preview and collaborative editing without polling. TypeGen closes the loop on developer experience by generating TypeScript types from your schema and queries, so the shape you queried is the shape your editor and frontend both type-check against. Fewer round trips, exact shapes, and end-to-end types are the concrete DX wins that a configured GraphQL layer asks you to assemble yourself.

Operations, preview, and enterprise governance

Customisation that ships to a real team has to survive operations: preview that matches production, roles that fence off who can touch what, and an audit trail when something goes wrong. This is where 'the editor is code you own' and 'the editor is a hosted product' both have to answer for governance, and it is worth being precise about what each side bundles.

Contentful provides Live Preview, roles and permissions, and audit logging on its higher tiers, with a mature hosted platform behind it. Some of the visual-editing experience arrives through their SDK and configuration rather than as a single toggle, so the integration work is real even though the capability exists.

Sanity bundles the pieces that make a customised editor operable. The Presentation Tool and Visual Editing stitch your custom Studio to a live frontend preview using Content Source Maps, so editors click an element on the rendered page and land on the field that produced it, even inside your custom inputs. Roles & Permissions, Audit logs, and Content Releases give you governed workflows on a headless stack. On compliance, Sanity is SOC 2 Type II, supports GDPR, offers regional hosting and data residency, and publishes its sub-processor list, which is the paperwork enterprise buyers actually request. Because the Studio is your React app deployed how you choose, you also control its hosting, authentication surface, and release cadence, which is the shared-foundation argument: one governed content backend feeding every channel rather than a silo per team.

Cost, lock-in, and how to decide

The honest tradeoff is ownership versus operability-out-of-the-box. Contentful's hosted editor means less to maintain and a faster start for teams that want a standardised tool, at the cost of a customisation ceiling and a pricing model that steps up as you add spaces, roles, and API traffic. When your needs fit inside their model, that is a feature, not a limitation.

Sanity's editor-as-code means you own a React application, which is more surface to maintain but far more room to shape, and it keeps the customisation in your repository rather than in a vendor's UI you cannot fully export. The customisation you write is standard React and standard schema definitions, which reduces the flavour of lock-in where your workflows live inside proprietary configuration.

Use this decision framework. Choose the hosted, configured model when editorial requirements are stable, the team wants zero frontend ownership over the editor, and the default field set covers the content model. Choose editor-as-code when your custom inputs need deep document context, when navigation and structure have to bend to your workflow, when you want one GROQ query to serve editor, preview, and frontend, and when governance plus real-time preview need to be part of the same owned system. Reframed plainly: the question is not which platform has more features, it is whether you want to configure someone else's editor or ship your own, and how much of your content operation you want living in code you control versus configuration you rent.