We've migrated dozens of enterprise sites between CMS platforms. Contentful to Sanity is one of the most common moves we see — and one of the most misunderstood. Here's what actually happens when you make the switch.

Why Companies Are Moving

Let's be honest: Contentful is a solid product. But we keep hearing the same pain points from enterprise teams:

  • Pricing at scale. Once you exceed the included API calls or need multiple environments, costs climb fast.
  • Content modeling rigidity. Contentful's content model works well for structured content, but complex compositions — page builders, nested modules, conditional fields — start to feel like fighting the system.
  • Real-time collaboration. Sanity's real-time, multiplayer editing experience is genuinely better for large editorial teams.
  • Customization ceiling. Sanity Studio is React-based and infinitely customizable. Contentful's UI is polished but opinionated.

The Migration Architecture

Every migration we run follows the same four-phase architecture:

Phase 1: Schema Mapping

Contentful content types map to Sanity document types, but the translation isn't always 1:1. Rich Text fields become Portable Text. References work differently. Localization is handled at the document level in Sanity vs. the field level in Contentful.

We build a mapping document first — every content type, every field, every edge case. This takes a day or two and saves weeks of debugging later.

Phase 2: Automated Content Export

We use Contentful's Management API to export everything: entries, assets, content types, locales. The key insight is to export all relationships as resolved references, not just IDs. This makes the transformation step dramatically simpler.

Phase 3: AI-Assisted Transformation

This is where it gets interesting. Traditional migration scripts are brittle — they break on edge cases, malformed content, and unexpected field values. We've built an AI-powered transformation pipeline that:

  • Handles rich text conversion with semantic understanding (not just regex)
  • Resolves ambiguous field mappings using content context
  • Generates Sanity-compatible Portable Text from Contentful's rich text AST
  • Flags content that needs human review instead of silently dropping it

Phase 4: Validation & Reconciliation

After import, we run automated validation: page-by-page visual comparison, link checking, asset verification, and content completeness scoring. Any page that scores below threshold gets flagged for manual review.

The Gotchas Nobody Warns You About

Asset References Are Tricky

Contentful assets have their own IDs. Sanity assets live in a CDN with different URL patterns. If your frontend code has hardcoded Contentful CDN URLs (it shouldn't, but it often does), those all need updating.

Webhooks Need Rebuilding

If you have webhooks triggering builds, preview environments, or downstream systems — those all need to be rebuilt for Sanity's webhook format. Budget time for this.

Editorial Training Is Half the Battle

Sanity Studio looks and feels completely different from Contentful. Your editorial team needs hands-on training, not just documentation. We always budget 2-3 sessions with content teams post-migration.

SEO Redirect Maps

If your URL structure changes at all (and it often does when slug generation logic differs), you need comprehensive redirect maps. We generate these automatically from the before/after content mapping.

Timeline & Cost Reality

For a typical enterprise site (200-500 pages, 10-15 content types, 2-3 locales):

  • Schema mapping: 2-3 days
  • Migration pipeline build: 1-2 weeks
  • Test migrations: 3-5 runs over 1-2 weeks
  • Final migration + validation: 1-2 days
  • Frontend updates: 1-3 weeks (depending on coupling)
  • Editorial training: 2-3 sessions

Total: 4-8 weeks. Not 4-8 months. The AI-assisted pipeline is what compresses the timeline — traditional approaches take 2-3x longer.

Should You Actually Migrate?

Not always. If Contentful is working for your team and your costs are manageable, the migration overhead might not be worth it. We've talked clients out of migrations when the ROI wasn't there.

But if you're hitting the ceiling on customization, struggling with editorial workflows, or watching your CMS bill climb — it's worth a serious conversation.

Reach out and we'll give you an honest assessment.