Quick Guide To Fix Error Message: err_ssl_server_cert_bad_format

Google Chrome is one of the world’s most popular and widely-used Web browsers. Many users rely on it, and it’s no exception that when someone tries to open the website, sometimes unwanted error messages occur. Some are common, and some such as err ssl server cert bad format are quite unheard of.

If you think what this message of error means, or how it can be solved, then you are not alone. It’s not an error that’s often seen, so it’s quite apparent you might wonder how this error message came about.

Let’s get into the particulars.

What is the reason for this error message: err_ssl_server_cert_bad_format Means & What does it cause?

It’s one of the SSL-based errors that occurs when you try to visit a website that has installed a self-signed SSL / TLS certificate instead of an SSL / TLS certificate provided by trusted Certificate Authority such as Sectigo or Comodo.

All popular web browsers like Google Chrome and Mozilla Firefox accept SSL / TLS certificates provided by known certificate authorities as trusted.

What is SSL / TLS Self-Signed Certificate?

Simply put, self-signed SSL / TLS certificates are the ones that are signed by the same person to whom the certificate must be issued. For example, website owner signing their own SSL certificate for their site. In addition, no trusted Certificate Authority such as Sectigo signs the signing procedure and the private key but the website owner himself.

How can this error message be resolved: err ssl server cert bad format?

A solution exists but it’s temporary.

To solve this problem follow the steps below:

Windows (10)

Click on and open the Windows icon at the bottom left corner and type Internet Options by double-clicking on it.

The Web Options

  1. It will open Properties on the Internet. From that, select the Safety tab and double-click Trusted Sites. It will pop up Trusted Sites open. Now insert the website URL, which displays an error message: err ssl server cert bad format in the “Add the site to zone:”
  2. Once you have added the URL to your website, click the Add button and then Close. Finally, click the OK button, and try to reopen the site.
  3. You can try this option over the web browser as well. At Google Chrome, for example,
  4. Click the top right corner on three dots, and click Settings.
  5. Click Advanced from the left panel, and select System.
  6. Once it opens, right-hand click Open the proxy settings of your computer.
  7. It will open Properties on the Internet. Now follow the steps quoted above for Windows (10).

But that’s not a permanent solution. Furthermore, if you are a website owner and are trying to permanently resolve this issue, you will not be able to do so unless you get the certificate installed from a trusted certificate authority. Because no web browser accepts self-signed SSL / TLS certificate, because it has many drawbacks that can not be overlooked. Furthermore, if anyone instals a self-signed SSL certificate, visitors to their website will face an error message.

However, if you are in doubt as to whether or not to go with the paid one from SSL / TLS certificate providers such as RapidSSL, Sectigo, or Comodo, then there is another option to get a free trial before making any final decision. RapidSSL CA, for example , offers an SSL Certificate as a cost-free 30 day trial.


First and foremost, one must avoid a self-signed SSL certificate. Unless you use it internally for testing purposes, then it is something else. In addition, if you are a visitor to the website who faces this error message: err ssl server cert bad format, then we recommend that you go through the above steps. If you’re a website owner, then we’d say installing an SSL / TLS Certificate from a respected Certificate Authority is best.