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@VS-Gary said in Why my website is giving 4xx error:

The site is on wordpress

Pinpoint the Specific 4xx Error Code:

Gather as much information as possible about the exact 4xx error code (e.g., 404 Not Found, 403 Forbidden, 400 Bad Request). This will guide you towards the most likely cause.
Check your server logs for detailed error messages, including timestamps and file paths. Use tools like WP Super Cache or Query Monitor to view detailed error information directly in your WordPress dashboard.
2. Troubleshoot Based on the Error Code:

404 Not Found:

Verify file/URL existence: Ensure the requested file or resource actually exists at the specified URL. Double-check spelling, capitalization, and relative/absolute path accuracy.
Permalinks configuration: Review your WordPress permalink settings (Settings > Permalinks) and ensure they're configured correctly, particularly if you've recently made changes.
URL rewriting conflicts: If using plugins or other modifications that rewrite URLs, temporarily disable them to see if they're causing the issue.
Caching: Clear your browser cache and any caching layers on your server (e.g., WP Super Cache, Cloudflare) to rule out outdated cached responses.
403 Forbidden:

File/directory permissions: Check file and directory permissions on your server using an FTP client or control panel. Ensure appropriate read/write permissions are set for the affected files and directories.
Plugin/theme conflicts: Temporarily deactivate all plugins and switch to a default WordPress theme to isolate if a plugin or theme is causing the issue. Re-enable them one by one to pinpoint the culprit.
.htaccess directives: Review your .htaccess file (often in the root directory) for any rules that might be blocking access unintentionally. Back up the file before making changes.
400 Bad Request:

URL length/complexity: Shorten or simplify URLs if they're excessively long or contain special characters. Avoid spaces, non-alphanumeric characters, and excessive query parameters.
Server limitations: Check your hosting provider's documentation for any limitations on request headers, payload size, or other factors that might trigger this error.
Plugin incompatibility: Update or deactivate plugins that might be interfering with form submissions or other operations that could lead to a 400 error.

Sometimes my website opens smoothly <a href="https://www.srinagarcabservices.com/">Srinagar cab services </a> but sometimes it shows error.

@VS-Gary This means there's something wrong at the server end in terms of configuration files..

Where are you hosted?