TokenMismatchException

Error Message

Symfony\Component\HttpKernel\Exception\TokenMismatchException

Cause

The CSRF token sent with the form doesn't match the token stored in the session. The session may have expired, or the token is stale.

Solution

Ensure @csrf is in every form. For SPAs, send the X-CSRF-TOKEN header. Clear browser cache and cookies. Check session configuration.

Code Example

Fix

@csrf {{-- Always include in Blade forms --}}

{{-- For SPA/AJAX --}}
<meta name="csrf-token" content="{{ csrf_token() }}">

{{-- Axios automatically sends the token from meta tag --}}
axios.defaults.headers.common['X-CSRF-TOKEN'] = 
    document.querySelector('meta[name="csrf-token"]').content;

Debugging Steps

Verify @csrf is in the form
Check session cookie exists in browser
Ensure session driver is configured
Clear cookies and try again
Check for multiple forms with different actions

Prevention

Use @csrf in every form. Configure session lifetime appropriately. For SPAs, ensure proper cookie handling.