The humble ad server - it was once a groundbreaking ad tech innovation and has now become the primary mode of delivering advertising on the internet. It may be commonplace, but the ad server remains an extraordinarily important part of web publishers’ revenue strategies.

As is the case with anything important to your ability to make a living, you have to make your choice of ad server with extreme care. You need to work with the best and leave the rest for your competitors.

This post will help you do that. Below, we have defined an ad server and compiled a list of the top ad servers in 2025.

Choosing the best ad server, ad network or ad exchange is hard work, and getting it wrong can have a major impact on your revenue. Wouldn’t it be nice if an expert could do it all for you? That’s not a dream - it’s a reality when you work with Playwire. Drop us a line if you’re interested.

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Ad Server Pillar

The Complete Guide to Ad Servers

Ad Server: Defined

Ad server, ad network, demand-side platform, supply-side platform - there’s a ton of terminology to nail down in the ad tech world. Let’s make sure we’re all talking about the same thing as we discuss ad servers.

 

 

What is an Ad Server?

Put very simply, an ad server is what actually puts advertisements in the places where people will see them online. It’s a piece of ad tech that occupies an incredibly important position in the digital advertising chain of production.

Ad servers contain sophisticated engines tuned to make fast, complex decisions about where to send ads. They work in real time to put an ad inside or near a piece of content as a user is engaging it. Ad targeting information and the results of programmatic auctions are fed into the decision engines to influence the decisions they make. 

Ad servers bring publishers and agencies together. They house ads and "serve" them to publishers' ad inventory slots using sophisticated decision engines and important ad targeting information. Ad servers need to have settings controlling every aspect of an ad impression, they must house all ad creatives, and information on every ad unit, and they have strong decision engines that select the most appropriate ad placement based on publisher and advertiser needs.

This is done in real time as users are engaging with publishers' content. Information from an ad network about the user informs the ad that the ad server ultimately displays. Finally, ad servers collect data on key metrics from an ad network, such as ad impressions, and report them to advertisers and publishers.

Ad networks, SSPs, and Publishers alike can all have their own ad servers or communicate with shared ad servers.

Those are the basics, but some ad servers do them better than others, and some do more.

Leading Ad Servers in 2025

With a baseline understanding of what an ad server is and how it works, you’re prepared to begin the process of choosing the server you will use for ads on your website or app. We have outlined seven of the top ad serving platforms in the business below.

 

 

The top ad serving platforms for publishers in 2025 are:

  1. Google Ad Manager
  2. Kevel
  3. Smart (Equativ)
  4. E-Planning
  5. Epom Ad Server
  6. Revive Ad Server
  7. OIO Publisher

Once known as DoubleClick for Publishers, Google Ad Manager is an ad server and supply-side platform (SSP) that connects publishers with programmatic demand, with support for both display ads and video ad units. It’s a Google product, so it has broad applicability and all the latest tech.

Publisher Benefits:

  • It’s a Google product, so it’s primed for the latest tech and timely updates
  • Relatively straightforward user interface
  • Comes with optimization, yield, and data management tools

Google Ad Manager Reviews:

One of the most commonly used ad tech tools in existence, Google Ad Manager is generally well-received among publishers who use it. It gets an 8.7 (out of 10) on TrustRadius and 4.1 (out of 5) on G2.

Related: Should I manage Google Ads myself or find a partner that does it for me?

 

GAM360

Google Ad Manager, or GAM360 falls under the larger Google Ad Manager umbrella. GAM360 is the premium version of Google Ad Manager.

On the free version of Google Ad Manager, Google must enforce limits on the ad inventory you can monetize to ensure the sustainability of the system. Google keeps an up-to-date listing of these limits for reference here. Pricing for premium seats for GAM360 is based on your size as a publisher, and the feature set is incredibly rich (sometimes overwhelmingly so).

Having access to a Google Certified Publishing partner can make it less expensive and simpler to access the powerful tools a paid seat in GAM360 offers.

Learn More About Google Ad Manager and GAM360

2. Kevel

Kevel is DIY done right. With its ad serving API, this platform allows publishers to build their own completely customized ad server in a matter of weeks. This is an excellent ad server solution for publishers who need something that’s made for them, but keep in mind that you have to have some programming knowledge to build a custom server.

Publisher Benefits:

  • Fully customizable, making it ideal for publishers with unique needs and high-tech capabilities
  • Ad server APIs allow publishers to bypass some ad blockers
  • Allows for automation of many manual processes within the server ecosystem

Kevel Reviews:

Mentioning customization and customer service as positives and a difficult user interface as negatives, Kevel users gave the ad server a 4.5 on G2 and a 4.6 on Capterra.

Learn More About Kevel

3. Smart (Equativ)

Smart’s ad server, now owned by Equativ, allows you to run both programmatic and direct campaigns across any and all channels. This ad server lives on the cutting edge to give publishers access to tech that allows them to truly optimize their yield.

Publisher Benefits:

  • Deemed one of the most promising up-and-coming technology companies
  • Premium demand partners
  • Vertically integrated ad server, SSP, and DSP

Smart Ad Server Reviews:

Even prior to being acquired by Equativ, Smart earned a fantastic 4.0 on G2 and a 4.3 on Capterra. In general, reviewers have tended to mention the ease of usage and control over their ad campaigns.

Learn More About Equativ

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Ad Server Resource Center

The Complete Ad Server Resource Center

4. E-Planning

Both an SSP and ad server, E-Planning gives publishers a full deck of ad tech to run programmatic advertising campaigns that really drive revenue. E-Planning has been in the ad server business for a while. It’s one of the oldest ad servers around, and that is apparent when you get a taste of this platform’s experience and understanding of publisher needs.

Publisher Benefits:

  • Easy integration with Prebid servers
  • Allows publishers to run direct private deals with over 200 DSPs
  • Advanced ad campaign targeting for location, language, time, and a wide variety of other factors

E-Planning Reviews:

E-Planning has gotten very few online reviews from publishers, but the few it has received earned it a 4-star rating on G2. Most of the negative reviews mentioned the need for E-Planning to hire some user experience professionals, while the positive reviews centered on its wide variety of campaign options to monetize ad inventory.

Learn More About E-Planning

5. Epom Ad Server

Epom is a well-known ad server that sweetens the deal with a total ad management platform. The company even offers a customizable, white-label ad server that you can make yours - branding and all.

Publisher Benefits:

  • Real-time ad performance tracking within the platform
  • Automated ad campaign optimization feature
  • Allows publishers to create custom dashboards

Epom Ad Server Reviews:

With a 4.4 on both G2 and Capterra, Epom is a consistently solid choice of ad server for most publishers. Reviewers often mentioned how the tool simplifies complex ad campaign management, but they also mentioned encountering trouble with Epom’s customer service team.

Learn More About Epom Ad Server

6. Revive Adserver

If you’re looking for a free ad server to monetize your ad inventory, then this is the one. Revive Adserver is 100% free and open-source, meaning many people can contribute to and modify the original source code. The open-source nature of Revive has given it a lot of handy features like in-depth reporting. It really is free, but that comes with its own cost: you have to know how to actually implement it, and that takes some tech know-how. 

Publisher Benefits:

  • 100% free and open-source
  • Simple setup and installation process
  • Built-in ad performance tracking

Revive Adserver Reviews:

With a 4.2 on Capterra and a 4.0 on G2, Revive Adserver is a solid server option - especially considering the price point. The most positive reviews discussed the open-source nature of this server, as well as the options for customization that come with that. But the negatives centered on a lack of support.

Learn More About Revive Adserver

7. OIO Publisher

This is another one for tech-minded publishers, but if you’re up for that challenge, you’ll come away paying relatively little. OIO Publisher comes as both a standalone program and a plugin for WordPress sites, and it costs a fraction of the monthly fee of most other top ad servers.

Publisher Benefits:

  • Low cost
  • Comes as a WordPress plugin to simplify installation and management
  • Plugin license use allowed across multiple domains

OIO Publisher Reviews:

OIO Publisher hasn’t been reviewed very heavily online, but the single review it had received on G2 as of the time of publication gave it 2.5 stars and called the tool “clunky yet functional.” 

Learn More About OIO Publisher

How to Stop Worrying About Ad Servers: Work with Playwire

You could spend a whole week researching all of the ad servers, and you very likely would still feel like you were taking a shot in the dark. That’s because all ad servers like to call themselves top ad servers, but only a few are the real deal. 

If you’re like many publishers, you’re tired of having to make all of these choices yourself and hope for the best. That’s why so many publishers have partnered with Playwire to amplify their ad revenue. We’re here to make sure you have access to the top ad serving platforms and make the most out of the rest of your ad tech stack including: incorporating the largest set of digital advertising demand, integrating the latest technology (like header bidding and our own proprietary Revenue Intelligence algorithm), and pretty much anything else you need to maximize your revenue. 

Interested? Then your next step is simple: contact Playwire. Reach out online.

Apply Now

Frequently Asked Questions

 

What is an ad server?

An ad server puts ads in front of eyeballs. You can say it in a few simple words, but what actually goes into that simple definition is a highly complex piece of advertising technology filled with important details and plenty of nuances.

Click here to learn A LOT more!

 

Are there different types of ad servers?

Yes. In fact, there are 7 different types of ad servers. Explore each below, and keep reading here for more information on each individual type of ad server.

  1. Open-source ad servers, which are servers that you host on your own servers. With this type of publisher ad server, the publisher grabs the source code for the ad server from a central repository and uploads it to their own server. From there, they can modify the source code to match your preferences and needs.

  2. First-party ad servers allow publishers to directly manage the sale of their ad inventory across various channels. These servers tend to be powerful and strong on data and reporting, allowing publishers to manage the minutiae that can make huge revenue impacts over time.

  3. Third-party ad servers are usually an advertising agency. They're also commonly called advertiser-side servers because they exist to serve buyers of ad inventory rather than publishers.
  4. Display ad servers are where ad placements on publisher websites and/or apps are based on the results of programmatic advertising auctions for the publishers' ad inventory. Most ad servers are display ad servers, but few are only display ad servers.
  5. Mobile ad servers are very similar to that of any other kind of ad server, however, the setup is unique. To serve ads to mobile apps, ad servers have to be integrated into the app publisher's tech stack via a software development kit (SDK). This integration can create technical problems if the SDK does not play well with the various other SDKs the publisher already has integrated. Once the technical difficulties are behind you, however, you can start serving mobile app ads and bringing in revenue.
  6. Video ad servers are necessary if you want to run video advertising of any kind. But don't worry - today, most advanced ad servers can accommodate video ads. Some are better than others, but most mainstream ad servers can process in-stream and out-stream video ads with relative ease.
  7. Rich media ad servers can accommodate multiple file types for a single ad. For example, to run a flex leaderboard, you may need audio, video and a still image to be served all at once. That's the job of a rich media ad server. If you want to run complex, premium ad units, you're probably going to need to have a rich media ad server.

More Ad Server Content

Browse some of our other articles about ad servers:

More on the Ad Tech Ecosystem

Are you interested in reviewing all your ad tech options but unsure where to begin given the complexity of the industry? Don't fret, Playwire has your back!

Learn more about all the players and tools that are available across the ad tech landscape with our new Ad Tech Ecosystem webpage, which is updated regularly, and includes information on ad networks, native ad solutions, consent management partners, data management platforms, and everything in between!