How to add adsense ads in sidebar of blogspot | Collapsed Sidebar not showing ads

If you have Google AdSense approved on your site, try connecting with the VPN of other countries. Sometimes there are no much ads to show in your own country. This is the reason why you may feel that Google AdSense is not serving ads in the side bar of your blog.

Before connecting to the VPN

After connecting to VPN: Observe the ad in blogger sidebar

Other questions that users ask is AdSense side bar ads are not showing in mobile but in PC or laptop they are seen. 

If this issue persists, and you are not able to see Adsense advertisements from your mobile phone then try using a different web browser. Since you might have given some permission or consent to one of the web browser, it might be blocking the Adsense advertisements to show. 

In the following case I was not able to see the advertisement in Android mobile when I was using Google Chrome but then I have downloaded Firefox browser and tried reloading a website to my surprise, I could find that the ads are showing again.

When using Firefox with VPN I could see advertisement in the sidebar

These advertisements I failed to see when I was using VPN with Google Chrome

What ad unit will be best for sidebar Blogspot

You may think that vertical 120/600 will be the best suited for your website. But, I will advise you to use responsive Adsense advertisements to put in your side bar.

Go to add gadget and AdSense then scroll down to responsive advertisements option.