Increased 520 error responses

We used to have only 10 - 20 520 errors but suddenly it has gone up to 4.6k 520 error responses on Jun 11th though our server looks absolutely fine. Similarly we have a got a lot of errors on Jun 10th as well. This looks very strange as nothing unusual happened in our server

Any help is highly appreciated…

Howdy! :cowboy_hat_face:

A 520 happens when your origin returns a response that is unexpected.

Review the Quick Fix Ideas in this Community Tip for troubleshooting suggestions.

Let us know if you have any further questions :slight_smile:

Sure…Will check the community tips…But is there any specific reasons for a sudden spike when nothing got changed in our server?

We had never encountered these errors before, but recently, we started experiencing them in production. After we disabled HTTP/2 to Origin, the errors disappeared.


@paskel.maksim…Thanks a lot. Your solution worked and disabling HTTP2 to Origin resolved the issue.
@CloudflareCan you please correlate and let us how disabling HTTP2 to origin reduced 520 errors.

I have also had this issue since 10th June and have disabled this setting.

Hello there, I was searching about 520 errors at Google, and I found this community. I’m not familiar with HTTP codes, but I wanted to ask why my site returns a 520 error whenever I check it with Ahrefs. Can anyone explain why this is happening?
My site URL is

@Joeito is anyone looking into this from Cloudflare’s side?

@Joeito ?