The Complete Guide to Migrating from Microsoft 365 to Google Workspace

Before You Start

Migrating from Microsoft 365 to Google Workspace is one of the most common migration paths. MigrateData supports all 13 data types for this direction, including email, calendar, contacts, files, tasks, notes, groups, shared mailboxes, shared calendars, shared drives, chat messages, mailbox rules, and public folders.

Here's what you need:

• Source: Microsoft 365 Global Admin account (for OAuth consent)
• Destination: Google Workspace Super Admin account (for domain-wide delegation)
• Time: 30 minutes for setup, then migration runs automatically

Step 1: Connect Your Platforms

Microsoft 365 (Source)

1. Log into MigrateData and go to Settings → Connections
2. Click Add Connection and select Microsoft 365
3. Sign in with your M365 Global Admin account
4. Grant the requested permissions (Mail, Calendar, Contacts, Files, etc.)
5. MigrateData stores only the OAuth token — encrypted with your tenant's unique key

Google Workspace (Destination)

1. Click Add Connection and select Google Workspace
2. Sign in with your Google Super Admin account
3. Grant domain-wide delegation for the required scopes
4. MigrateData can now act on behalf of any user in your Google organization

Step 2: Run Discovery

1. Go to Discovery and click New Scan
2. Select your M365 connection as the source
3. Choose which services to scan (Email, Calendar, Files, etc.)
4. Click Start Scan

Discovery takes 2-10 minutes depending on organization size. You'll see:

• Total users and their mailbox sizes
• Data volume by type (email, files, calendar)
• Estimated migration time
• AI-powered risk analysis

Step 3: Plan Your Migration

Phased Rollout (Recommended for 100+ users)

Instead of migrating everyone at once, create separate migration jobs for each phase:

• Phase 1: IT team (5-10 users) — validate the process
• Phase 2: VIP executives — ensure critical users are migrated smoothly
• Phase 3+: Department by department

Use CSV upload or resource selection in the migration wizard to specify exactly which users are included in each phase.

Select Data Types

Choose which data types to migrate. We recommend starting with email and calendar (highest priority), then adding files, contacts, and other types.

Step 4: Start Migration

1. Go to Migrations → New Migration
2. Select source (M365) and destination (Google Workspace)
3. Choose data types and users
4. Review the AI pre-migration analysis for any warnings
5. Click Start Migration

What Happens During Migration

• Email: Messages are streamed from Exchange Online to Gmail. Original dates are preserved. Folder structure maps to Gmail labels. Attachments are included.
• Calendar: Events are converted from Microsoft's recurrence format to Google's RRULE format. Attendees, reminders, and attachments are preserved.
• Files: OneDrive files are streamed to Google Drive. Office documents (DOCX, XLSX, PPTX) can be converted to Google Docs format or kept as-is.
• Contacts: Contact fields are mapped between Microsoft's schema and Google's schema.

Real-Time Monitoring

Watch progress on the live dashboard:

• Per-user progress bars
• Item counts (completed, failed, skipped)
• Data transferred in real-time
• Error details for any failed items

Step 5: Post-Migration Verification

After migration completes, run Reconciliation:

1. Basic Mode: Compares database records — fast, no API calls
2. Detailed Mode: Verifies items exist on the destination via API
3. Full Mode: Compares sizes and names for complete verification

Any discrepancies can be selectively re-migrated with one click.

Step 6: Set Up Delta Sync

If you need a coexistence period (users still receiving email on M365 while transitioning to Google):

1. Create a Delta Sync job linked to your migration
2. Set sync interval (e.g., every 15 minutes)
3. Enable Cutover Mode with your DNS switchover date
4. Delta sync automatically stops 48 hours after cutover

Tips for Success

• Test first: Migrate 2-3 test users before the full migration
• Communicate: Inform users about the migration schedule
• Check shared resources: Shared mailboxes, shared calendars, and shared drives need explicit selection
• Format conversion: Decide upfront whether to convert Office files to Google format
• OU placement: For Google Workspace, use CSV target_ou to organize users into the correct OUs

Need Help?

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