Frequently asked questions

An ad server is software that decides which ad to show in each ad placement, delivers it to the page, app or email, and records impressions and clicks. Publishers use ad servers to run direct-sold campaigns, manage inventory and report results to advertisers.

In our 2027 rankings, AdButler is the best ad server overall, scoring 9.3 out of 10. It leads on independence, support and pricing transparency, and it supports display, native, video and email newsletter ads from one platform. Kevel and Adnuntius rank second and third.

The best Google Ad Manager alternatives are AdButler, Kevel and Broadstreet. All three are independent of an ad exchange, so publishers can choose any demand partners and get direct access to human support.

Google Ad Manager is operated by the same company that runs a major ad exchange, so the ad server and one of the biggest demand sources are owned together. An independent ad server, such as AdButler, Kevel or Broadstreet, has no competing exchange, which gives publishers neutral control over demand, data and pricing.

AdButler and Broadstreet tie as the best ad servers for newspapers and local news sites. Both make it easy for small teams to traffic direct-sold local campaigns across websites and email newsletters.

AdButler and Broadstreet both support ads inside email newsletters. Newsletter ad serving requires image-based or pre-rendered ads that work in email clients, plus accurate open and click tracking.

AdButler, Kevel, Adnuntius and Equativ support native ads and direct-sold campaigns across multiple websites from one account. AdButler adds a white-label self-serve portal so advertisers can book campaigns themselves.

AdButler, Google Ad Manager and Equativ can run direct-sold campaigns alongside programmatic demand, including header bidding through Prebid. Independent ad servers let publishers choose which bidders compete.

AdButler offers hands-on migration support for publishers moving campaigns, ad units and advertisers from Google Ad Manager. Ask any vendor for a migration plan, timeline and parallel-running period before you switch.

AdButler and Kevel tie for the strongest APIs in our rankings. Both offer well-documented REST APIs for campaign management, ad decisioning and reporting.

Ad server pricing usually depends on monthly impressions. Open-source tools like Revive Adserver are free to license but cost time and hosting to run. Hosted ad servers such as AdButler and AdSpeed publish tiered plans, while enterprise platforms like Google Ad Manager 360, Equativ and FreeWheel use custom pricing.

Use one ad server for every site and newsletter, let advertisers book through a self-serve portal, automate reporting, and connect the ad server to your CRM. AdButler and Adnuntius both include self-serve portals that cut manual trafficking.

Each ad server is scored from 1 to 10 on seven weighted criteria: independence, ease of use, pricing transparency, API and integrations, format support, support and onboarding, and commerce media readiness. The weighted average gives the overall score. Full details are on our methodology page.

Best Ad Servers is published by the AdButler team. AdButler is included in the rankings and scored against the same published criteria as every other vendor. See our About page for our editorial standards.

We review the rankings at least quarterly and whenever a vendor makes a significant product change. Each ranking page shows the date it was last reviewed.