CMS to CMS Website Migration

Migrating from One CMS to Another

CMS-to-CMS migration is primarily a data migration. Differences in schemas, fields, content types and media files require transformation, not simple copying.

Typical Migration Paths

Export Tools

WordPress — built-in XML Export or WP-CLI:

wp export --post_type=post,page,product --dir=/tmp/wp-export/

Drupal — Migrate API or CSV export:

drush migrate-import --all

Contentful — CMA SDK:

contentful space export --space-id $SPACE_ID --export-dir ./backup

Ghost — Ghost Admin → Settings → Export → Export your content (JSON).

Strapi — custom script via REST API.

Transformation Script

ETL pattern (Extract → Transform → Load):

// scripts/cms-migration.ts
interface MigrationConfig {
  source: 'wordpress' | 'contentful' | 'ghost';
  target: 'strapi' | 'contentful' | 'sanity';
  contentTypes: ContentTypeMapping[];
}

async function migrate(config: MigrationConfig) {
  const extractor = getExtractor(config.source);
  const transformer = getTransformer(config.source, config.target);
  const loader = getLoader(config.target);

  for (const mapping of config.contentTypes) {
    console.log(`Migrating: ${mapping.sourceName} → ${mapping.targetName}`);

    // Extract
    const items = await extractor.extract(mapping.sourceName);

    // Transform
    const transformed = items.map(item => transformer.transform(item, mapping));

    // Load (with batching)
    for (const batch of chunk(transformed, 50)) {
      await loader.load(mapping.targetName, batch);
      await delay(500);
    }
  }
}

Rich Text Migration

Most complex part — transforming Rich Text formats:

// WordPress HTML → Portable Text (Sanity)
import { htmlToPortableText } from '@portabletext/html';

function transformWpContent(html: string) {
  return htmlToPortableText(html, {
    rules: [
      {
        deserialize(el, next, block) {
          if (el.tagName === 'IMG') {
            return block({
              _type: 'image',
              _key: Math.random().toString(36).slice(2),
              src: el.getAttribute('src'),
              alt: el.getAttribute('alt'),
            });
          }
        },
      },
    ],
  });
}

URL Redirect Mapping

After migration, definitely set up 301 redirects:

// Generate mapping of old → new URLs
const redirects = oldPosts.map(old => ({
  source:      old.url,
  destination: newPosts.find(n => n.slug === old.slug)?.url ?? '/blog',
  permanent:   true,
}));

// next.config.ts
async redirects() {
  return redirects;
},

Migration between two headless CMS (1000–5000 items) — 2–4 weeks.