Hello,
We apologize for the issue you are facing with the API Error: HTTP 400 during your SEO analysis. This error typically indicates that the server is unable to process your API request due to a client error. Here are some common reasons and potential fixes:
-
Website Under Maintenance: If your website is under maintenance, it cannot be accessed, leading to this error. Ensure your website is back to normal mode.

-
Check Website Status: If your website isn’t returning a 200 status code, you can check its status here. Enter your website URL and click Check Status.

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API Timeout: If your website takes more than 30 seconds to load, it may result in a timeout error.
-
API Requests Blocked by Firewall: Your server’s firewall might be blocking our API requests. You may need to whitelist the IP 46.30.211.100
and the user-agent RankMathApi/2.0.2; https://rankmath.com
.
-
Locally Hosted Website: The SEO Analyzer module only works on live sites that return a 200 OK status when crawled from an external site. If your site is hosted locally, the SEO Analyzer will not function properly.

If you continue to experience issues, please reply to this ticket with your website URL so we can assist you further.
Sources:
Why Am I Getting "API Error: HTTP 400" Error » Rank Math
Why Am I Getting "API Error: HTTP 400" Error » Rank Math
Hello,
Thank you for contacting us and sorry for any inconvenience that might have been caused due to that.
We tested your website with our external SEO Analyzer and we are getting the ‘Invalid server response’.
Please check with your host and share your server & site’s IP addresses so we can check if your site is getting blocked from our end.
Looking forward to helping you.
I add the IP in the sensitive data box.
Hello,
We added the IP address of your website to our whitelist and the SEO Analyzer is now able to access the website.
If you still see issues on your website, you will need to check your own firewall and whitelist the IP address and user agent mentioned here: https://rankmath.com/kb/api-http-400-error/
Thank you.
Hello,
Since we did not hear back from you for 15 days, we are assuming that you found the solution. We are closing this support ticket.
If you still need assistance or any other help, please feel free to open a new support ticket, and we will be more than happy to assist.
Thank you.