Outlook Online: How to Sign In and Use Outlook on the Web

To use Outlook online, go to outlook.com if you have a personal Microsoft account (Outlook.com, Hotmail, Live), or outlook.office.com if your email comes from work or school. Both run Outlook entirely in your browser, so there’s nothing to install: sign in with your Microsoft account and your inbox, calendar and contacts load in the tab.

The rest of this guide covers which address to use, how to sign in and out safely, what browsers and storage you get, and when the web version is (and isn’t) the right choice compared with the desktop apps. Details reflect Microsoft’s documentation as of October 2026 and can change.

Outlook.com vs Outlook on the web: which one is yours?

Microsoft uses two names for what is essentially the same browser-based Outlook. Which one you use depends on the account, not on the device.

Microsoft’s sign-in article for Outlook on the web describes Outlook.com as the web-based version of Outlook for personal accounts, and points work and school users to outlook.office.com or the Microsoft 365 portal. If you use a work account and aren’t sure, your IT department may have given you a specific address to use; that takes priority over general advice.

How to sign in to Outlook online

Personal account (Outlook.com)

1. Open your browser and go to outlook.com.
2. Select Sign in.
3. Enter your Microsoft account email address, then select Next.
4. Enter your password.
5. Complete any verification prompt. Microsoft may ask you to confirm your identity when you sign in from a new device or location.

Per Microsoft’s Outlook.com sign-in page, since February 2025 you stay signed in automatically unless you sign out or browse privately. On a shared computer, clear the Keep me signed in option on the password screen, or use a private window.

Work or school account

1. Go to outlook.office.com, or sign in at Microsoft365.com and pick Outlook from the app list.
2. Enter the email address and password your organization assigned.
3. Approve any multi-factor authentication prompt your organization requires.

If you land in the wrong mailbox, Microsoft’s advice is simply to sign out and sign back in with the correct account. If your password or sign-in method doesn’t work, contact your organization’s help desk rather than Microsoft consumer support, because your admin controls the account.

Signing out properly

Microsoft’s sign-out guide says to select your initials or profile picture in the top corner of the inbox and choose Sign out, then close all browser windows. If the profile picture doesn’t appear, an ad blocker may be hiding it. If you’ve lost access to a device where you were signed in, Microsoft offers a separate option to sign out everywhere from your Microsoft account security settings.

A quick safety note: only ever sign in on outlook.com, outlook.office.com or Microsoft365.com (or a link your organization provides). Phishing pages often copy the Outlook sign-in screen, so check the address bar before typing a password.

Browser requirements

According to Microsoft’s supported browsers page, Outlook online works best in the latest versions of:

• Windows: Microsoft Edge, Chrome or Firefox
• macOS: Edge, Safari 16 or later, Chrome or Firefox
• Linux: Chrome or Firefox, though some features may not be available

Older browsers such as Internet Explorer, Chrome 79 and earlier, and Safari 13.1 and earlier are being phased out, and users on them see an error page asking them to upgrade. Microsoft also notes that ad blockers and pop-up blockers can stop Outlook.com from loading correctly, so they’re the first thing to check if the page is blank or half-rendered.

Storage: how much space you get

For personal accounts, Microsoft’s storage limits article lists:

• Free Outlook.com: 15 GB of email storage, separate from your cloud storage.
• Free cloud storage: 5 GB shared across OneDrive files and photos, Outlook.com attachments and Microsoft 365 apps.
• Microsoft 365 subscribers: a 100 GB mailbox per person. Microsoft notes this isn’t available on trial subscriptions and takes effect shortly after a paid subscription starts.

You may still find an older Microsoft page quoting 50 GB for subscribers; the current support article says 100 GB.

What happens if you hit the limit matters: Microsoft says you won’t be able to send or receive email, and messages sent to you bounce back to the sender. To free space, open Settings > Storage in Outlook.com, where you can see which folders take up room and permanently delete items, including bulk deletion of messages older than 3, 6 or 12 months.

Work and school mailbox sizes are set by your organization’s plan, so check with your admin if you’re running low.

Can you use Outlook online offline?

Mostly no. Microsoft’s support content says offline access isn’t available in the new Outlook on the web. An older offline mode existed in the classic Outlook Web App on laptops and desktops, but that documentation targets on-premises Exchange Server 2010/2013 setups and doesn’t apply to most people today.

If you regularly work without a connection, use Outlook for Windows or Mac, or the Outlook mobile app, which keep a local copy of your mail.

Outlook online vs the new Outlook for Windows

If you’re on Windows, you’ve probably seen the new Outlook for Windows app. It’s worth knowing how closely it’s related to the web version. Microsoft’s Learn overview explains that the new Outlook is built on Outlook on the web: the experience is provided by the web app, wrapped in a Windows component (using WebView2) that gives it access to local features such as richer notifications.

In practice that means:

• The interface and most features in the new Outlook app and Outlook online are very similar.
• Add-ins: COM add-ins aren’t supported in the new Outlook; web add-ins are the replacement. The same web add-in model applies in the browser.
• For organizations: Microsoft notes that Outlook on the web must be enabled for a user’s mailbox before the new Outlook app can be deployed to them.

Third-party coverage, such as CodeTwo’s timeline of the new Outlook, tracks rollout dates for business users, but sources disagree on exact timing for commercial and enterprise customers, and some features found in classic Outlook (for example COM add-ins and some local data file workflows) are still missing. If your team relies on those, keep classic Outlook available and check Microsoft’s own documentation for the latest status.

When the web version is the right choice

Outlook online is a good fit when you:

• Switch between computers or use a shared or locked-down machine where you can’t install software.
• Use Linux or a Chromebook-style setup.
• Want the same experience as the new Outlook for Windows without installing it.
• Need quick access to calendar and contacts alongside email in one tab.

It’s a weaker fit if you need reliable offline access, depend on COM add-ins or macros, or manage several large local mailbox archives. In those cases the classic desktop app is still the more practical tool, at least for now.

Quick troubleshooting checklist

1. Confirm the right address: outlook.com for personal accounts, outlook.office.com for work or school.
2. Update your browser to the latest Edge, Chrome, Firefox or Safari.
3. Disable ad and pop-up blockers for the Outlook site and reload.
4. Try a private window to rule out a stale signed-in session or extension conflict.
5. Check storage under Settings > Storage if mail suddenly stops arriving.
6. Work accounts: contact your IT help desk if sign-in is blocked; your organization controls access policies.