New Outlook or classic Outlook for Windows - which to use

Updated 24 September 2026For Microsoft 365

Outlook for Windows now comes in two versions: classic Outlook, the one most people know, and new Outlook, which looks and works like Outlook on the web. Both open the same Microsoft 365 mailbox, and you can switch between them with the toggle at the top right.

How to tell which one you have

Look at the top of the window:

Classic Outlook has a File menu at the top left and a large ribbon of buttons.
New Outlook has no File menu, a simpler toolbar, and a New Outlook toggle turned on at the top right.

Microsoft has started calling the new version simply “Outlook for Windows”, so you may see both names.

What is different in new Outlook

Most day-to-day work is the same. Microsoft’s own comparison lists these differences, which matter most for small offices:

Add-ins: new Outlook only runs web add-ins. Older COM add-ins, often used by accounting, CRM and PDF tools, do not work.
PST files: new Outlook can import email, calendar, contacts and tasks from a PST file, but support is still partial.
Offline: working without internet is partly available. Classic Outlook still works offline more completely.
Shared mailboxes: supported, with some features still missing, such as shared contacts.
Settings: signatures, automatic replies and other settings are set up again in new Outlook. See signatures and out of office.

Try the new Outlook

Your email stays safe on the server whichever version you use, so trying it costs nothing.

In classic Outlook, turn on the Try the new Outlook toggle at the top right.
New Outlook downloads and opens. When asked, choose Import Settings to bring over your settings, or Skip.
Sign in with your work account if asked.

Go back to classic Outlook

In new Outlook, turn the New Outlook toggle off at the top right. Classic Outlook opens again straight away. Both apps stay installed, so you can switch again later.

If your company has moved everyone to new Outlook, you may see prompts such as Switch now that move you after a few launches. Your admin can also hide the toggle, in which case ask them before switching back.

Which should you use?

Use new Outlook if you mostly read and send email and want the same look as Outlook on the web. Stay on classic Outlook if you rely on a COM add-in, work offline a lot, or use PST archives heavily. Microsoft says classic Outlook stays supported until at least 2029.

Still stuck

WhatsApp our support team at +60 16-916 3324.

Common issues

My Outlook suddenly looks different. What happened?

You have probably been moved to the new Outlook, either by turning on the toggle or because your company switched it on. Your email is the same; only the app changed. You can usually go back by turning the New Outlook toggle off at the top right.

Where are my PST files and add-ins in the new Outlook?

New Outlook can import email, calendar, contacts and tasks from PST files, but it does not support the older COM add-ins that some accounting or CRM tools use. If you depend on those, stay on classic Outlook for now.

Will classic Outlook stop working?

Not soon. Microsoft says classic Outlook will be supported until at least 2029, and it promises at least 12 months' notice before each change.

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