Moving from Google Workspace to Microsoft 365: A Migration Guide

A Google Workspace to Microsoft 365 migration moves mail, calendars, contacts and Drive files with tools Microsoft includes in the subscription, and most of that data arrives intact. The trouble is at the edges. Google Docs, Sheets and Slides are converted to Word, Excel and PowerPoint files and can lose formatting on the way. Shared drive permissions only survive if you rebuild the matching groups first. Google Groups, Chat history, Sites and external sharing links do not migrate at all. A sound plan accepts those facts up front: run both systems side by side for a short coexistence period, move mail on a planned cutover weekend, and put real training time in front of people who have only ever used Gmail. The project is measured in weeks, and the risk lives in the planning rather than the data copy.

What moves cleanly from Google Workspace to Microsoft 365?

Mail, calendar and contacts move with the Google Workspace migration built into Exchange Online. Microsoft's migration documentation lists mail and rules, calendar and contacts as the supported data, and the process runs in batches. Gmail labels arrive as Outlook folders, so a message with three labels shows up in three folders; warn people. Gmail filters become Outlook rules and are migrated switched off, so each person should review them before turning them on.

Files move with Migration Manager in the Microsoft 365 admin center. It scans each drive, maps Google users and groups to Microsoft 365 identities, and copies My Drive content to OneDrive and shared drives to SharePoint. Microsoft's Migration Manager FAQ states that when identities are fully mapped, content is reshared after migration so each user keeps the access they had, and that version history moves with each file. Copies are incremental, and nothing is deleted from Google. Microsoft's overview also describes a Lite mode for tenants under 300 licenses that skips the scan and mapping steps; avoid it if you have shared drives, because the mapping is what preserves permissions.

What does not move, and what do you do about it?

Start with the documents. Migration Manager converts .gdoc, .gsheet and .gslide files into .docx, .xlsx and .pptx through Google's export, as described on Microsoft's unsupported files page. Plain documents convert well. Long documents with custom styles, Sheets that depend on Google-only functions or Apps Script, and Slides with embedded fonts need a review pass. We have each department name its twenty most important files, open each in Office after the first migration run, and log what needs fixing.

Next, permissions. Shared drive permissions transfer only when a Microsoft 365 group with the same membership exists and is mapped to the Google group before the migration runs; that is Microsoft's own recommendation in the FAQ. External sharing links are not recreated, and content is not shared with external collaborators at all. Every link you have handed to a client or an accountant stops working and must be reissued from SharePoint or OneDrive under the sharing policy you choose for the new tenant.

Then the things with no migration path. Google Groups are rebuilt by hand as Microsoft 365 groups, distribution lists or shared mailboxes, depending on how each was used. Google Chat history has no supported import into Teams; export it and start fresh. Sites and Maps cannot be exported by the tool, so Sites are rebuilt as SharePoint pages. Forms migrate when you set a Forms destination, Drawings arrive as PNG images, and shortcuts, orphaned files and files marked restricted are skipped. On the mail side, Microsoft notes that vacation settings, shared calendars, room bookings and event colors are not migrated. None of these are showstoppers, but each needs an owner.

How does coexistence work while both systems are live?

Coexistence is the period when Microsoft 365 is provisioned and receiving copied data while Google is still the system of record. Microsoft's prerequisites call for users to be provisioned in Microsoft 365 before the batches run, and for a mail routing subdomain on each side so the two tenants can pass messages while delivery still goes to Google. The first mailbox and file batches then copy in the background over several nights.

A few rules keep coexistence from turning into a mess. Do not rearrange folders during the copy; the FAQ warns that renamed folders are treated as new content and duplicated on the next pass. Freeze new Google Groups and shared drives once mapping is done. Add new hires in Microsoft 365 first. Disable Google retention and archive rules that delete or move mail, because the migration tool reports those items as missing. Our cloud migration FAQ covers the general sequencing.

Use the time to make the decisions the tools will not make for you: which shared drives become Teams-connected SharePoint sites and which become plain libraries (our SharePoint vs OneDrive FAQ explains the split), what the external sharing policy will be, who owns each rebuilt group, and whether the plan is Business Standard or Business Premium. Premium adds Intune, Defender for Business and conditional access, which belong switched on before cutover; our Premium vs Standard comparison lays out the difference.

What happens on the cutover weekend?

Cutover is the moment mail delivery moves. On Friday evening the final incremental file pass runs and the last mail batches complete overnight. On Saturday the MX record is pointed at Exchange Online and the SPF, DKIM and DMARC records are updated so mail from the new tenant is not treated as spam; our email authentication FAQ covers those records. Google keeps receiving stragglers for a day or two through the routing subdomain, and a final small batch picks them up.

Devices are the other half of the weekend. Phones need the Outlook app and a work account; laptops need Microsoft 365 Apps and OneDrive signed in, and on Business Premium, enrolling them in Intune during cutover puts the security baseline in place on day one. Keep Google licensed and read-only for a month or two afterwards so a missing file can be pulled by hand, and do not cancel it until every department has signed off. Once the data is in Microsoft 365 it is yours to protect, so a third-party backup belongs on the post-migration list; our Microsoft 365 backup guide explains why.

How do you train people who have only ever used Gmail?

Training is where Google to Microsoft migrations succeed or fail, because the mental model changes. Gmail users think in labels and search; Outlook users think in folders and rules. Drive users share by link; SharePoint users share by site membership. Thirty minutes per group before cutover, with the converted files on screen, prevents most of the calls.

Keep it concrete: where the migrated labels landed, how to share from OneDrive and what the recipient sees, how a converted Doc looks in Word, and the fact that Teams replaces Chat and Meet without bringing Chat history along. Write a one-page "where things went" sheet per department, and treat the Monday after cutover as a support event with someone reachable from seven. If the platform question is still open, start with our comparison of Microsoft 365 vs Google Workspace.

Frequently asked questions

Can we keep our domain and email addresses when we move to Microsoft 365?

Yes. You verify the same domain in Microsoft 365, create users with the same addresses, and change the MX record at cutover so mail is delivered to Exchange Online instead of Gmail. Nobody's address changes. Aliases and group addresses must be recreated deliberately, since Google Groups do not migrate, and the SPF, DKIM and DMARC records must be updated so the new tenant's mail is trusted. Keep the Google tenant receiving mail through the routing subdomain for a short overlap.

Do Google Docs convert to Word automatically during migration?

Yes. Migration Manager converts Google Docs, Sheets and Slides into Word, Excel and PowerPoint files as it copies them and leaves the originals untouched. Ordinary documents convert well. Files that use Google-specific functions, Apps Script, unusual fonts or heavy custom styling can lose fidelity, so review the important ones after the first pass and fix them before cutover. Formatting differences are the most common complaint in the first week.

What happens to Google Groups and shared drive permissions?

Google Groups do not migrate. Each is rebuilt in Microsoft 365 as a Microsoft 365 group, a distribution list or a shared mailbox, depending on how it was used. Shared drive permissions do transfer, but only when a Microsoft 365 group with matching membership exists and is mapped to the Google group in Migration Manager before the copy runs. External sharing links are dropped in every case and must be reissued after migration.

How long does a Google Workspace to Microsoft 365 migration take?

For a small or mid-sized business the project usually spans several weeks from planning to the end of coexistence, with most of that time spent on decisions and background copying rather than downtime. The cutover itself is a single weekend. What stretches the timeline is the number of shared drives, the amount of external sharing to reissue and the number of Google Groups to rebuild. A scan of every drive before you commit to a date is the only reliable estimate.

Our Microsoft 365 migration service runs this whole sequence: licensing, identity mapping, mailbox and file batches, the cutover weekend, device setup and training, then manages the tenant afterwards on a month-to-month agreement with security switched on from day one. Talk to us before you pick a cutover date and we will scan your drives and tell you what will and will not move.