When you try to sign in to Notion, the application may display a ‘Sign In Failed’ error message and prevent access to your workspace. This error typically occurs due to one of three root causes: an expired or revoked authentication token, a network connectivity problem that blocks Notion’s login servers, or a corrupt local cache file that stores outdated session data. This article will explain why each cause triggers the error and provide step-by-step fixes for all three scenarios.
Key Takeaways: Fixing the Notion Sign In Failed Error
- Settings & Members > My Account > Log Out: Forces a fresh authentication token by logging out completely before signing in again.
- Windows Settings > Network & Internet > Network Reset: Resets network adapters and clears DNS cache to resolve connectivity blocks.
- %AppData%\Notion\Cache: Deleting the local cache folder removes corrupt session files that cause sign-in failures.
Why Notion Displays the ‘Sign In Failed’ Error
Notion uses an authentication token stored locally on your device to verify your identity each time you launch the application. This token has a limited lifespan and must be refreshed periodically by the Notion server. When the token expires or becomes corrupted, the server rejects the sign-in request and returns the ‘Sign In Failed’ error. A second common cause is a network interruption that prevents Notion from reaching its login servers at auth.notion.so. Firewall rules, VPN configurations, or proxy settings can block this connection. A third cause is a corrupt cache file in the local Notion data folder. The cache stores session data, and if that file becomes damaged, the application cannot complete the authentication handshake.
Steps to Resolve the Notion Sign In Failed Error
Method 1: Log Out and Sign In Again
Logging out forces Notion to discard the current authentication token and request a new one from the server. This is the fastest fix for token-related failures.
- Open Notion and go to Settings & Members
Click your profile picture or initials in the top-left corner of the Notion window and select Settings & Members from the dropdown menu. - Navigate to My Account
In the left sidebar of the Settings & Members window, click My Account. - Click Log Out
Scroll to the bottom of the My Account page and click the red Log Out button. Notion will close the window and return you to the login screen. - Sign in again with your email and password
Enter your Notion account credentials and click Continue. If you use single sign-on (SSO) or Google/Apple sign-in, select the appropriate option and follow the prompts.
Method 2: Check Network Connectivity
A blocked connection to Notion’s authentication servers can cause the error. Verify that your network allows traffic to auth.notion.so and api.notion.com.
- Test basic internet access
Open a web browser and go to a site like google.com. If the page does not load, your internet connection is down. Restart your modem and router, then try signing in again. - Disable VPN or proxy temporarily
If you use a VPN service or a proxy server, turn it off. Notion may block traffic from certain VPN endpoints. After disabling the VPN, attempt to sign in again. - Run a network reset on Windows
Open Windows Settings, go to Network & Internet, scroll down and click Advanced network settings, then click Network reset. Click Reset now and confirm. Your PC will restart and network adapters will be reinstalled. After the restart, try signing in to Notion. - Check firewall and antivirus rules
Open your Windows Firewall or third-party antivirus software and ensure that Notion is allowed through the firewall. If Notion is blocked, add an exception for the Notion executable located at C:\Users\[YourUsername]\AppData\Local\Programs\Notion\Notion.exe.
Method 3: Clear the Notion Local Cache
Corrupt cache files can prevent Notion from completing the sign-in process. Deleting the cache folder forces Notion to rebuild it with fresh session data.
- Close Notion completely
Right-click the Notion icon in the system tray (bottom-right corner of the taskbar) and select Quit. Alternatively, open Task Manager with Ctrl+Shift+Escape, find Notion under Processes, right-click it, and choose End task. - Open the Run dialog
Press Windows Key + R on your keyboard to open the Run command box. - Navigate to the Notion cache folder
Type %AppData%\Notion and press Enter. This opens the folder located at C:\Users\[YourUsername]\AppData\Roaming\Notion. - Delete the Cache folder
Inside the Notion folder, locate the Cache folder. Right-click it and select Delete. If prompted by Windows, confirm the deletion. - Restart Notion and sign in
Open Notion again. The application will create a new Cache folder automatically. Enter your credentials and click Continue.
If Notion Still Shows the Sign In Failed Error
Error persists after logging out
If logging out does not resolve the error, the token may be corrupted at the server level. Visit the Notion Status page at status.notion.so to check if there is an ongoing authentication outage. If the status page shows a green checkmark for Authentication, contact Notion support directly by emailing team@makenotion.com and include a screenshot of the error message.
Error appears only on one device
If you can sign in on another computer or mobile device but not on a specific PC, the issue is local. Run a full antivirus scan on the affected computer to rule out malware that may be interfering with Notion’s network traffic. Also check the date and time settings on your PC — an incorrect system clock can cause SSL certificate validation failures that trigger the sign-in error. Open Windows Settings > Time & Language > Date & Time and turn on Set time automatically.
Error appears after a Notion update
A recent Notion update may have introduced a bug that breaks the sign-in flow. Reinstall Notion to restore a clean version. Open Windows Settings > Apps > Installed apps, find Notion, click the three-dot menu, and select Uninstall. Then download the latest installer from notion.com/desktop and install it again.
Notion Desktop vs Web App: Sign-In Behavior Compared
| Item | Desktop App (Windows 10 / 11) | Web App (Browser) |
|---|---|---|
| Authentication method | Local token stored in AppData | Session cookie stored in browser cache |
| Common failure cause | Corrupt cache folder or expired token | Blocked third-party cookies or outdated browser |
| Fix for sign-in error | Delete Cache folder or log out via My Account | Clear browser cookies and cache, or use incognito mode |
| Offline access after sign-in | Partial — cached pages available | None — requires active internet |
You can now fix the Notion ‘Sign In Failed’ error by logging out, checking your network, or clearing the local cache. Start with the logout method because it is the fastest. If the error returns frequently, consider using the Notion web app in a browser as a fallback while you investigate the desktop app issue. A helpful advanced tip: press Ctrl+Shift+I in the desktop app to open the developer console and look for red error messages containing 401 or 403 status codes, which indicate token or permission problems respectively.