Why Your Australian Website Is Returning 505 HTTP Version Not Supported Errors

Summary

This guide helps you troubleshoot and resolve: Why Your Australian Website Is Returning 505 HTTP Version Not Supported Errors. Follow the steps below to fix the issue.

Common Causes

When a visitor attempts to load your website, their browser sends a request using a specific version of the Hypertext Transfer Protocol (HTTP). If your web server does not recognise or support that version, it responds with a 505 HTTP Version Not Supported error. Unlike a 500 Internal Server Error, which indicates something is broken on the server, a 505 error specifically means the server refuses to support the protocol version requested by the client. For Australian small businesses, this often means customers cannot access your site at all, leading to lost enquiries and sales.

Quick Fix Steps

1. Refresh the page to see if the error is temporary.
2. Try accessing the website from a different web browser or device.
3. Clear your browser cache and cookies.
4. Check if your website is loading for others using an online uptime checker.
5. Contact your hosting provider to confirm which HTTP versions your server supports.

Detailed Instructions

Refresh and Test Across Browsers

1. Press F5 or Ctrl + R (Windows) / Cmd + R (Mac) to reload the page.
2. Open the website in a different browser, such as Google Chrome, Mozilla Firefox, Microsoft Edge, or Apple Safari.
3. If the site loads in one browser but not another, the issue is likely related to that specific browser's request headers or protocol negotiation.

Clear Browser Cache and Cookies

1. Google Chrome: Click the three-dot menu, select Settings, go to Privacy and security, choose Clear browsing data, select Cookies and other site data and Cached images and files, then click Clear data.
2. Microsoft Edge: Click the three-dot menu, select Settings, go to Privacy, search, and services, under Clear browsing data click Choose what to clear, select the relevant options, and click Clear now.
3. Apple Safari: Click Safari in the top menu, select Settings (or Preferences), go to the Privacy tab, click Manage Website Data, then click Remove All.
4. Mozilla Firefox: Click the three-line menu, select Settings, go to Privacy & Security, under Cookies and Site Data click Clear Data, ensure both options are checked, and click Clear.

Verify Server Protocol Support

1. Log in to your web hosting control panel (such as cPanel, Plesk, or a custom dashboard provided by your host).
2. Look for sections labelled PHP Settings, Web Server, Apache, NGINX, or Server Configuration.
3. Check whether the server is configured to support HTTP/1.1, HTTP/2, or HTTP/3. Most modern browsers expect at least HTTP/1.1.
4. If you are on a shared hosting plan, your ability to change protocol versions may be limited. In this case, contact your hosting provider and ask them to confirm that HTTP/1.1 is enabled for your account.

Review .htaccess and Server Configuration Files

1. Connect to your hosting account using an FTP client or the File Manager in your control panel.
2. Locate the .htaccess file in your website's root directory (commonly /public_html/ or /www/).
3. Download a backup copy of the file before making any changes.
4. Open the file in a plain text editor and look for any directives that force a specific HTTP protocol version or restrict protocol negotiation.
5. If you find unfamiliar rules, comment them out by placing a # at the start of the line, save the file, and refresh your website.

Editing server configuration files can cause your website to go offline if done incorrectly. Always download a backup before making changes.

Troubleshooting

Check for Proxy or CDN Issues

1. If you use a Content Delivery Network (CDN) such as Cloudflare, log in to your CDN dashboard.
2. Check the SSL/TLS settings and ensure the origin server is configured to accept connections from the CDN.
3. Temporarily pause the CDN or switch to "DNS Only" mode to see if the error persists. If the site loads without the CDN, the issue is likely with the CDN's protocol settings.

Test from a Different Network

1. Disconnect from your current Wi-Fi and connect using mobile data on a smartphone.
2. Attempt to load the website again.
3. If the site loads on mobile data, the issue may be related to your local network, router, or ISP caching an outdated protocol handshake.

When to Escalate

If you have verified that your browser is up to date, cleared your cache, and confirmed the error occurs across multiple devices and networks, the problem is almost certainly on the server side. Your hosting provider will need to update the web server software or adjust protocol settings to support the version requested by visitors.

Do not guess at server configuration changes. Incorrect edits to httpd.conf, nginx.conf, or .htaccess can take your entire website offline.

If you host with us, you don't need to do this yourself — just Open a Ticket and our Brisbane team will get it sorted.

If you need assistance from your hosting provider, log in to the support portal and open a ticket. Include the exact error message, the time it occurred, and whether it affects all visitors or only specific devices.

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