Clear Cache and Cookies in Outlook: Step-by-Step

To clear Outlook cookies, remove the site data for Outlook in the browser you use. To refresh cached mail in the desktop app, use the steps for your Outlook version below; clearing browser cookies does not clear the desktop app’s mail cache. Save any unsent work first, because clearing site data or resetting an app can sign you out.

What You’ll Need

A few minutes and access to the browser or device where the Outlook problem occurs.
Your Microsoft 365, work, school, or Outlook.com sign-in details. You may need to complete multi-factor authentication after clearing cookies or resetting the app.
A reliable internet connection if Outlook needs to download mail again.

Step-by-Step

Identify which Outlook you use. Outlook on the web runs in a browser, usually at Outlook.com or your organization’s Microsoft 365 address. New Outlook for Windows is an installed app with a modern interface. Classic Outlook for Windows has the traditional desktop ribbon and is often part of Microsoft 365. Outlook for Mac is a separate desktop app. Use the matching instructions below; cookies apply to the browser, not usually to a desktop Outlook installation.
For Outlook on the web, remove only Outlook’s browser data if possible. First save drafts and close other Outlook tabs. In Microsoft Edge, open Settings, then go to Cookies and site permissions > Manage and delete cookies and site data > See all cookies and site data. Search for Outlook or Microsoft domains used by your organization, such as outlook.office.com, outlook.live.com, or office.com, and remove the matching site data. Domain names can differ depending on how your organization signs in, so remove only the entries clearly associated with the affected Outlook service. Close and reopen the browser, visit Outlook again, and sign in.
If you cannot find Outlook site data, clear it through your browser’s browsing-data controls. In Edge, go to Settings > Privacy, search, and services > Clear browsing data > Choose what to clear. In Chrome, open Settings > Privacy and security > Delete browsing data. In Firefox, open Settings > Privacy & Security, then use Cookies and Site Data. Select cookies and other site data; select cached images and files too if you want to refresh stored page files. Choose a time range that includes the problem, then confirm. This may sign you out of other websites as well. Browser menus can change slightly between releases, so use the settings search box for “cookies” if a label differs.
For New Outlook on Windows, try Repair before Reset. Close Outlook. In Windows 11, open Start > Settings > Apps > Installed apps, find Outlook (new), select the three-dot menu, and choose Advanced options. Select Repair first, then launch Outlook and check whether the issue is fixed. Repair is intended to address app problems without the broader effect of a reset. If it does not help, return to Advanced options and choose Reset. Windows 10 users can find the app under Settings > Apps > Apps & features, then open its advanced options. A reset can remove local app data and sign you out, so be ready to add or authenticate your account again. Mail stored in your online mailbox is not deleted by clearing local app data, but check that drafts and outbox messages have finished syncing before you reset.
For Classic Outlook on Windows, refresh a folder’s offline copy. This is more targeted than deleting Outlook data files. Open Outlook and let it connect, then right-click the affected mail folder and select Properties. On the General tab, choose Clear Offline Items, then select OK. Select the folder again and use Send/Receive > Update Folder, or use the Folder tab’s Update Folder command if that is what your ribbon shows. Outlook will download that folder’s current contents again. Repeat only for folders that appear stale; large folders can take time to resync. This does not clear browser cookies and should not be confused with deleting your Outlook account or mailbox.
For Outlook on Mac, start with the affected folder and avoid deleting files manually. In the legacy Outlook interface, Control-click or right-click the folder, choose Properties, and select Empty Cache if that command is available. Then use Tools > Sync > Sync This Folder, or the sync command shown in your version, and wait for the folder to update. The New Outlook for Mac interface may not offer the same Empty Cache command. In that version, quit and reopen Outlook and install available updates first; use the account’s sync or reset options only if they appear in your build and you understand that you may need to sign in again. If Outlook for Mac is only displaying Outlook on the web in a browser, follow the browser instructions instead.
Check the result before repeating anything. Reopen the affected folder or webpage, allow time for synchronization, and look for the original symptom: a sign-in loop, missing recent messages, old formatting, or a loading error. If the issue is resolved, stop there. Repeatedly clearing data can cause extra sign-ins and longer downloads without improving Outlook.

Common Mistakes

Clearing all browser data when only Outlook needs attention. Removing cookies for every site can sign you out of shopping, banking, and other accounts. Prefer deleting Outlook-related site data only. If you must clear all cookies, expect to sign back in elsewhere.

Assuming cookies and the desktop mail cache are the same thing. Cookies and cached website files belong to the browser. A desktop Outlook app stores local data separately. Clearing Chrome or Edge data will not rebuild the offline mailbox used by Classic Outlook.

Deleting an OST, PST, or random Outlook folder. These files and folders can contain important local information or settings. Do not remove them as a first-line cache fix. In particular, PST files can hold mail that is not stored on a server. Use Outlook’s own folder cache or Windows app repair controls instead, and ask your organization’s support team before changing managed files.

Resetting before checking drafts and sync status. A message in the Outbox or a draft that has not synchronized may exist only on the device. Connect to the internet and confirm important messages are saved or sent before resetting an app or clearing local folder contents.

Expecting a cache clear to fix every account problem. Expired passwords, service outages, full mailboxes, and organization sign-in policies are not repaired by removing cookies. Repeatedly clearing data can make sign-in harder without addressing the cause.

Tips

Try a private or InPrivate browser window before clearing anything. If Outlook works there, an extension, stored site data, or browser profile setting may be involved.
Close Outlook tabs before removing browser data, then reopen a single tab. Keeping multiple signed-in tabs open can make it unclear whether the new session has taken effect.
Use a folder-specific refresh in Classic Outlook when only one folder is stale. Avoid rebuilding the entire profile unless narrower steps fail or support recommends it.
Keep Outlook and your browser up to date. Updates can resolve compatibility and sign-in problems that a cache clear cannot.
If this is a work or school account, note any error message and the time it occurred. Your administrator may need that information to check access rules or a Microsoft 365 service issue.

Troubleshooting

Outlook keeps asking you to sign in. Check that cookies are enabled for the Microsoft sign-in and Outlook sites your organization uses. Allow any required pop-ups or redirects, temporarily disable privacy extensions for the site, and try again. Confirm the device date and time are correct. If the account uses multi-factor authentication, complete the prompt rather than repeatedly clearing cookies. Work or school users may need their administrator to review conditional-access requirements.

Messages do not reappear after refreshing a folder. Confirm Outlook is online and that the folder is part of the account’s server mailbox. In Classic Outlook, check Send/Receive status and allow the download to finish. If older mail is missing, check Outlook on the web to see whether it is present on the server. If it is absent there too, clearing a local cache will not restore it; check Deleted Items, archive locations, or contact your mail administrator.

New Outlook still has the same error after Repair or Reset. Restart Windows, check for app updates in Microsoft Store, and verify that Outlook can reach the internet. If only one account is affected, confirm the account works in Outlook on the web. If the app will not open or the issue affects multiple users, collect the error details and contact Microsoft support or your organization’s help desk rather than deleting more data.

The browser instructions do not match your screen. Browser settings vary by version. Search settings for “site data” or “cookies,” then find the list of stored site permissions or data and remove the Outlook-related entry. If you are unsure which domain is safe to delete, clear cached images and files first; this refreshes page resources without necessarily removing sign-in cookies.

Frequently Asked Questions

Will clearing Outlook cache delete my emails?
Removing browser data or resetting New Outlook does not normally delete mail stored in the online mailbox. Clearing a folder’s offline copy makes Outlook download it again. However, unsent drafts or messages that exist only on the device may be at risk, so confirm they are saved or synchronized first.

How often should I clear Outlook cookies?
There is no routine schedule. Clear them when Outlook on the web has a sign-in loop, stale page behavior, or a loading problem that persists after refreshing. Cookies keep a session active, so clearing them unnecessarily means signing in again.

Does clearing cache remove my Outlook password?
It can end a browser session, but it does not necessarily erase a password saved in the browser’s password manager. A desktop app reset can require you to authenticate again. Make sure you know how to access your account and complete any required verification before proceeding.

Should I turn off Cached Exchange Mode in Classic Outlook?
Usually not just to clear a cache. Cached Exchange Mode controls how Outlook keeps a local copy of mailbox data for offline use. Changing it affects how mail is stored and accessed, and it is different from refreshing one folder’s offline items. Leave it as configured unless support advises otherwise.

Can I clear cookies from the Outlook desktop app?
There is no universal cookie-clearing command shared by the desktop versions. For Outlook on the web, use the browser’s site-data controls. For a Windows or Mac app, use the version-specific repair, reset, or folder-sync options above rather than deleting browser cookies.

Will clearing cookies fix Outlook not syncing?
It may help if the problem is in Outlook on the web, but it will not usually fix desktop synchronization. Check your connection and service status, then refresh the affected folder or repair the app as appropriate. If mail is missing from Outlook on the web too, contact your administrator or email provider.

Try it: the Date Difference Calculator: days, months, years and weekdays between two dates, with the DATEDIF formulas.

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