You open Visual Studio Code and see a red error banner: “GitHub Copilot: Request failed with status code 401.” This means Copilot cannot verify your identity with GitHub servers. The 401 error appears when your authentication token is expired, missing, or revoked. This article explains why the error occurs and provides step-by-step fixes to restore Copilot functionality.
Key Takeaways: Fixing Copilot 401 Authentication Error
- VS Code command palette > GitHub Copilot: Sign Out: Clears the current invalid session and forces a fresh login.
- VS Code command palette > GitHub Copilot: Sign In: Re-authenticates via browser with a new token.
- GitHub account settings > Copilot > Revoke token: Manually removes a stuck or corrupted token from GitHub servers.
Why the 401 Error Occurs with GitHub Copilot
The 401 HTTP status code means “Unauthorized.” Copilot sends a request to the GitHub API, but the server rejects the attached authentication token. This can happen for several reasons:
Your GitHub session token expired. Tokens issued by GitHub have a limited lifetime. When the token expires, Copilot cannot authenticate your subscription, and the 401 error appears.
Your Copilot subscription was revoked or changed. If your organization removed your Copilot license or your personal subscription lapsed, GitHub invalidates your token. The next time Copilot tries to connect, it receives a 401 response.
A corrupted or duplicate token exists in VS Code. If you signed in multiple times or used different GitHub accounts, VS Code might hold a stale token that no longer matches your active subscription. The server sees this as an invalid credential.
Network proxies or VPNs interfere with token validation. Some corporate proxies strip or modify authentication headers. When the header is missing or altered, GitHub responds with 401.
Steps to Fix the 401 Authentication Error
The following steps are ordered from the simplest to the most thorough fix. Start with step 1 and proceed only if the error persists.
- Sign out of GitHub Copilot
Open VS Code. Press Ctrl+Shift+P to open the command palette. Type GitHub Copilot: Sign Out and press Enter. This removes the current authentication session from VS Code. - Sign in to GitHub Copilot again
Open the command palette again with Ctrl+Shift+P. Type GitHub Copilot: Sign In and press Enter. A browser window opens. Sign in with your GitHub account that has an active Copilot subscription. After you authorize the app, return to VS Code. The 401 error should be gone. - Clear VS Code authentication cache
If signing out and back in does not work, clear the cached tokens manually. Open the command palette and run Developer: Reload Window. This reloads the extension host and clears in-memory tokens. Then repeat steps 1 and 2. - Revoke the token from GitHub website
Go to github.com/settings/tokens. Look for any token named Visual Studio Code or GitHub Copilot. Click the Delete button next to it. Return to VS Code and sign in again using step 2. This forces GitHub to issue a new token. - Check your Copilot subscription status
Open a browser and go to github.com/settings/copilot. Confirm that Copilot is active and shows a green checkmark. If your subscription has expired, renew it through GitHub. After renewal, repeat steps 1 and 2. - Disable proxy or VPN temporarily
If you use a corporate proxy or VPN, disable it and try signing in again. If the error disappears, configure the proxy to allow traffic to api.github.com and copilot-proxy.githubusercontent.com on port 443. Add these domains to your proxy’s allowlist.
If Copilot Still Shows 401 After the Main Fix
Copilot extension is outdated
An old extension version might not support the latest authentication protocol. Open the Extensions view in VS Code. Find GitHub Copilot. If an update is available, click the Update button. Reload VS Code and sign in again.
Multiple GitHub accounts conflict
If you are signed into multiple GitHub accounts in VS Code, Copilot might use the wrong one. Open the command palette and run GitHub: Sign Out for each account except the one with the Copilot license. Then sign in to Copilot using the correct account.
Firewall blocks required endpoints
Your network firewall might block the URLs Copilot uses for authentication. Ensure that the following domains are reachable from your machine: api.github.com, github.com, copilot-proxy.githubusercontent.com. Test connectivity by running ping api.github.com in a terminal. If the ping fails, contact your network administrator.
Token rotation policy in your organization
Some organizations enforce token rotation every 24 hours. If your token is rotated automatically, VS Code might not refresh it. In this case, sign out and sign in at the start of each workday. Alternatively, ask your admin to extend the token lifetime.
Manual Token Refresh vs Automatic Token Refresh
| Item | Manual Token Refresh | Automatic Token Refresh |
|---|---|---|
| Trigger | User runs Sign Out and Sign In commands | VS Code refreshes token in background |
| User action required | Yes, each time the token expires | No, happens silently |
| Best for | Organizations with strict token rotation | Personal accounts with default token lifetime |
| Reliability | Guaranteed to work after manual step | Can fail if extension is outdated |
The 401 error is almost always a token or subscription issue. Signing out and signing in resolves most cases. If the error persists, revoke the token from GitHub and check your subscription status. For users behind corporate proxies, adding the required domains to the allowlist is the final step. After following these steps, Copilot will authenticate correctly and resume suggesting code.