What is Prebid?

It was created in 2015 by leading marketers and publishers as an alternative to ‘waterfall’ auctions, and has since become the industry standard.

Prebid has grown in popularity due to its simplicity and effectiveness; it allows for more competition among ad buyers, leading to higher CPMs for publishers. In addition, Prebid is easy to set up and can be implemented quickly on most ad servers. It’s become an important tool for publishers who want to maximize their ad revenue, and for advertisers who want to ensure they are getting the most bang for their buck.

What Is Prebid.js?

Prebid.js is an open source tool available to advertisers looking to implement header bidding on websites and apps. It works via a JavaScript tag, which  is placed on the web page or app and executed when the page loads. The tag makes a call to each ad exchange that has been configured by the advertiser, in order to fetch bids for the ad inventory. The ad exchange then responds with the bids, which are passed back to Prebid.js. The JavaScript then determines which bid is the highest, and displays the corresponding ad.

Prebid.js takes place on the client-side, meaning that all of the auctioning and decision-making happens in the user’s browser. It’s important to note that Prebid.js is not an ad server; rather, it’s a tool that can be used in conjunction with an ad server, such as Google Ad Manager.

Prebid.js is the most popular tool for implementing header bidding, and is used by a number of major publishers, including The Washington Post, Forbes, and Hearst. In addition, a number of ad tech companies offer support for Prebid.js, including AppNexus, Index Exchange, Rubicon Project, and Sovrn.

What Is Prebid Server?

Prebid Server is an open source tool that can be used to implement server-side header bidding. It works by sending requests to ad exchanges in order to fetch bids for the ad inventory, and then passes the bids back to the ad server. The ad server then determines which bid is the highest, and displays the corresponding ad.

Prebid Server takes place on the server-side, meaning that all of the auctioning and decision-making happens on the server. This is in contrast to Prebid.js, which takes place on the client-side.

Prebid Server is less popular than Prebid.js, but has a number of advantages over client-side header bidding, including improved latency and increased control for publishers.  In addition, Prebid Server is compatible with a wider range of ad servers, including Google Ad Manager and Amazon Publisher Services.

The Main Differences Between The Two

Although they perform the same function, Prebid.js and Prebid Server function in unique ways and  offer different advantages. Here is a breakdown of some of the most notable.

Auction side: Prebid.js occurs on the client-side, while Prebid Server happens on the server-side of things. While  both have their pros and cons, server-side header bidding is generally seen as being more efficient, due to the fact that client-side header bidding can add latency to the page.

Ad server: Prebid.js does not include an ad server, while Prebid Server does. This means that if you’re using Prebid.js, you’ll need to use an ad server in order to actually serve the ads on your page. However, if you’re using Prebid Server, the ad server is built in, which can save you time and money.

Setup: For advertisers that don’t have  a lot of technical expertise, Prebid.js can be easier to set up than Prebid Server. It’s managed by the Prebid.org community, which offers a number of resources to help with implementation.

Performance: Both Prebid.js and Prebid Server are known for being fast and efficient, but server-side header bidding generally has an edge in this area, due to the fact that it does not add latency to the page.

Control: Prebid Server gives publishers more control over the header bidding process than Prebid.js, due to the fact that it takes place on the server-side. This can be a major advantage for publishers that want to have more control over the ads that are served on their site.

Compatibility: Prebid.js is compatible with a wider range of ad servers than Prebid Server. However, Prebid Server is compatible with a wider range of ad exchanges.

Cost: Both Prebid.js and Prebid Server are free to use. However, if you’re using Prebid.js, you’ll also need to use an ad server, which can cost money.