Migrating your on-premises SharePoint 2016 environment to SharePoint Online unlocks modern collaboration, built-in security, and seamless integration with Microsoft 365. Yet without a clear roadmap, you risk downtime, data loss, and frustrated users. This guide walks you through the ten essential phases of a successful migration—from initial assessment to post-go-live optimization.

Discovery & Assessment

Objectives: Inventory content, customizations, and dependencies.

  • Content census: Use tools like SharePoint Migration Assessment Tool (SMAT) to catalog sites, lists, libraries, storage, version histories.

  • Customization audit: Identify farm solutions, sandboxed code, custom web parts, workflows (SharePoint Designer, InfoPath).

  • Permissions review: Extract current permission models and site ownership.

  • Network & bandwidth: Measure upload speeds and plan throttling windows for large migrations.

Tip: Classify sites by business criticality to prioritize migration waves.

Strategy & Planning

Objectives: Define scope, approach, timeline, and success criteria.

  • Migration approach:

    • Lift-and-shift (database attach): Quick but carries legacy architecture.

    • Modernization wave: Re-architect key intranets as modern Communication or Team sites.

    • Hybrid islands: Keep select workloads on-premises if needed during transition.

  • Timeline & phases: Schedule pilot → Wave 1 (pilot refinements) → Waves 2–N (bulk migration) → Decommission.

  • Governance blueprint: Update information architecture, taxonomy, retention labels for the cloud.

Environment Preparation

Objectives: Ready both source and target for migration.

  • SharePoint Online tenant setup:

    • Create hub/site collection architecture.

    • Configure custom domains, site designs, and global navigation.

  • On-prem cleanup:

    • Archive or delete stale sites/files.

    • Resolve orphaned users and broken links.

  • Identity & Authentication:

    • Implement Azure AD Connect for directory synchronization.

    • Enable Modern Authentication and MFA.

  1. Proof of Concept (PoC)

Objectives: Validate your process on a small, representative sample.

  • Migrate a non-critical site collection end-to-end.

  • Test manual vs. automated migrations with SharePoint Migration Tool (SPMT) or third-party tools (ShareGate, Metalogix).

  • Validate permissions, metadata, version history, and page layout fidelity.

  • Gather user feedback on modern UI and navigation.

Content Migration

Objectives: Move documents, lists, pages, and metadata at scale.

  • Tool selection:

    • Microsoft SPMT: Free, good for simple lifts.

    • ShareGate / Metalogix: Paid, advanced scheduling, pre-migration analysis, transformation.

  • Mapping rules:

    • Map on-premises URLs to new site URLs.

    • Transform deprecated columns into modern metadata.

  • Scheduling & throttling:

    • Automate incremental syncs (delta migrations) to minimize cut-over window.

    • Use off-peak hours for bulk loads.

Customization & Modernization

Objectives: Replace or refactor legacy custom code.

  • SPFx vs. Classic web parts: Rebuild critical web parts using SharePoint Framework.

  • Power Platform: Convert InfoPath forms to Power Apps; legacy workflows to Power Automate flows.

  • Branding: Apply tenant-wide themes, header/footer using site designs and site scripts.

Testing & Validation

Objectives: Ensure completeness and quality before cut-over.

  • Content spot-checks: Verify document counts, metadata, version history.

  • Functional tests: Exercise customized apps, forms, and navigation.

  • Performance tests: Measure page load times and search relevancy.

  • User acceptance testing (UAT): Business users confirm critical scenarios (e.g., invoice approvals, onboarding lists).

Cut-Over & Go-Live

Objectives: Final sync, DNS switch, and user onboarding.

  • Final delta migration: Capture last-minute changes.

  • DNS updates: Redirect on-prem portal URL to SharePoint Online home site.

  • Communications:

    • Send go-live alerts with new URLs, OneDrive changes, and support contacts.

    • Host virtual “intranet launch” walkthrough wheels.

  • Support ramp-up: Stand up a “concierge desk” via Teams for immediate issue resolution.

Post-Migration Optimization

Objectives: Tune, train, and govern your new environment.

  • Search tuning: Refine query rules and result sources based on usage analytics.

  • Permissions audit: Ensure no over-permissioned sites slipped through.

  • Adoption programs:

    • Hands-on workshops, “SharePoint champions” network.

    • Release bite-sized “power user” tips via Yammer or Teams.

  • Monitor & iterate: Use the Microsoft 365 admin center to track site usage, storage growth, and feature rollouts.

Decommission & Archive

Objectives: Safely retire the old farm and free up on-premises resources.

  • Export or archive remaining on-prem data.

  • Decommission database servers and application servers.

  • Update runbooks, architectural diagrams, and governance docs to reflect the cloud-only topology.

Conclusion

Migrating from SharePoint 2016 to SharePoint Online is more than a technical lift; it’s an opportunity to modernize your information architecture, streamline governance, and empower users with a next-generation collaboration workspace. By following a structured, phased approach you’ll minimize risk, accelerate adoption, and ensure your intranet scales seamlessly with your organization.

Next Steps:

  1. Run a free assessment with the SharePoint Migration Assessment Tool (SMAT).

  2. Pilot your first site with SPMT or ShareGate.

  3. Build your hub-and-spoke architecture in SharePoint Online.

Ready to transform your intranet? Let’s get started!