Update (2017): There’s no longer a limit on the number of ads you can show per page. However, I would advise you keep it to a maximum of 5.
Are you wondering how many Google Adsense ads are allowed per page? Google clearly states the number of ad units allowed per page but a lot of people never took the time to read through the terms of service when signing up. I was using two Adsense for mobile unit per page on the mobile version of this blog not knowing I was breaking the rule. I came across one of Google’s help articles on Adsense guidelines which clearly states that I was going against the big ‘G’ golden rules.
When you add more than three AdSense for content units on a web page, only three are shown and the rest won’t be displayed automatically but the case is different with mobile web. The other ads will still show up even when you’ve exceeded the limit.
Google Adsense For Content – You’re allowed to show a maximum of three ad units per page
Link Units – You’re also allowed to display a maximum of three link units per page
Adsense for search – Only two search forms are allowed. Anything more than that is clearly going against the terms of service
Adsense for mobile – Only one Adsense for mobile unit is allowed on a mobile web page. There are two types of Adsense for mobile unit: single and double unit. It’s allowed to put the single unit anywhere on your web page but it’s clearly stated that if you’re going to use the double unit, it must be placed at the bottom of the page.
Placing more than the allowed ads per page attracts a ban and there’s no excuse even if you didn’t know.