# **🔍 What Is the Nginx 444 Error?**

When you try to add a site to an OTTO project and see a **"No sites found"** error, the root cause may be your web server silently dropping the connection before Search Atlas can crawl the site. A **444 status code** is specific to Nginx — it instructs the server to close the connection immediately without sending any response. Unlike a standard 403 or 429 error, a 444 response produces no error message, making it harder to diagnose.

This is not a problem with your OTTO configuration. It means the Nginx server hosting your site is actively blocking the Search Atlas crawler before the crawl can begin.

# **⚙️ Why Nginx Returns a 444 to Search Atlas**

Nginx servers can be configured to return a 444 for requests that match certain conditions, including:

- Requests from unrecognised or unlisted user-agent strings
- Requests from IP address ranges not explicitly permitted in the server configuration
- Security rules that treat automated crawlers as malicious traffic by default
- Rate-limiting or bot-mitigation rules that trigger on crawl patterns

Because the connection is dropped silently, the Search Atlas platform receives no usable response and cannot confirm the site exists — which is why OTTO reports **"No sites found"** instead of a clear access-denied message.

# **✅ How to Whitelist the Search Atlas Crawler**

To allow the Search Atlas crawler through your Nginx server, you need to permit its user-agent and/or IP ranges in your Nginx configuration. Follow the steps below or share them with your hosting provider or developer.

1. **Identify your Nginx configuration file.** This is typically located at **/etc/nginx/nginx.conf** or inside **/etc/nginx/sites-available/** for your specific domain.
2. **Whitelist the Search Atlas user-agent.** Add a rule that allows requests from the Search Atlas crawler user-agent. Your developer should add a condition that checks for the Search Atlas bot user-agent string and ensures it is not matched by any **return 444** or **deny** directive. Contact support via the chat widget below to obtain the exact current user-agent string for the Search Atlas crawler.
3. **Whitelist Search Atlas IP ranges.** Add the Search Atlas crawler IP addresses to your allowlist before any deny-all or connection-drop rules. Contact support via the chat widget below to obtain the current list of Search Atlas crawler IP addresses.
4. **Check the order of your Nginx rules.** Nginx processes rules sequentially. Ensure your whitelist rules appear **before** any blanket bot-blocking or rate-limiting rules, otherwise the allow rule will never be reached.
5. **Reload Nginx to apply changes.** Run **sudo nginx -t** to validate the configuration syntax, then run **sudo systemctl reload nginx** to apply the changes without downtime.
6. **Re-add your site in OTTO.** Navigate to **OTTO SEO** in the left sidebar and open **All Sites (SEO Automation)**, open your OTTO project, and attempt to add the site again. The crawler should now be able to reach the site and the "No sites found" error should be resolved.

# **🛡️ If You Use a Third-Party Firewall or CDN Alongside Nginx**

If your Nginx server sits behind an additional layer such as a CDN or a web application firewall, the 444 block may be applied at the Nginx level even if your CDN settings appear to allow crawlers. Check both layers:

- **Nginx configuration** — review all **return 444** and **deny** directives, particularly inside **if** blocks that evaluate the user-agent or remote address.
- **WAF or CDN rules** — confirm that bot-fight or challenge modes are not re-blocking the crawler after Nginx has been updated. Refer to your CDN provider's documentation for steps to whitelist specific user-agents or IP ranges at the CDN level.

Both layers must permit the Search Atlas crawler for the connection to succeed.

# **🔎 How to Confirm the Block Is Resolved**

After updating your configuration, you can verify the fix before re-adding the site in OTTO:

- Use a tool such as **curl -A "[Search Atlas user-agent]" https://yourdomain.com** from a terminal to simulate a crawler request and confirm the server returns a 200 response instead of dropping the connection.
- Check your Nginx access logs (**/var/log/nginx/access.log**) to confirm requests from the Search Atlas user-agent are no longer returning 444.
- Once confirmed, navigate to **OTTO SEO** in the left sidebar and open **All Sites (SEO Automation)**, then retry adding the site to your OTTO project.

# **💬 Need Help?**

If you need further assistance, open the chat widget in the bottom-right corner of the platform and type **human teammate** to be connected with a member of our team.