Top supply side platform (SSP) and ad exchange companies
June 5, 2026 8 min read 69 views
Ever since the first ad was displayed in 1994, the programmatic industry has enjoyed a rapid increase in new tech and processes to help publishers monetize their websites and mobile apps. The first tools publishers used to sell their available ad space were ad networks. Then, supply side platforms (SSPs) came along. Then came ad exchanges and real-time bidding (RTB). Nowadays, there are many pieces of technology and services that help publishers manage their inventory and monetize their websites, mobile apps, and other properties. Below we list supply side platform examples and ad exchanges used by publishers and app developers, including top SSPs like Magnite, PubMatic, Index Exchange, OpenX, Equativ, and Google Ad Manager.
What is a supply side platform (SSP)?
A supply side platform is an advertising technology platform that helps publishers monetize their websites and mobile apps by managing, selling, and optimizing their available digital ad inventory (also known as ad space). SSPs provide publishers with the tools to coordinate ad placement decisions in real time, connecting their inventory to a range of demand sources including DSPs, ad networks, and exchanges. They are a key player in real-time bidding (RTB) media transactions, whereby publishers sell display, video, and native ad space to advertisers on an impression-by-impression basis.
While they are mainly used to sell inventory on websites and in mobile apps, SSPs are now used across platforms, including DOOH and CTV, to sell ad space for publishers. The shift has come to give publishers a single point of coordination across formats that once lived in separate stacks.
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What is an ad exchange and DSPs?
An ad exchange is a marketplace where buyers and sellers come together to trade digital media. The buyers (i.e. advertisers and agencies) use demand side platforms (DSPs) to bid on individual impressions. These impressions are put up for sale by sellers (i.e. publishers) via supply side platforms (SSPs).
This buying and selling process is handled by real-time bidding (RTB).
Ad exchanges were once standalone platforms, and many still are today, but over the past few years many AdTech companies have incorporated ad exchange functionality into their SSPs, and vice versa. This allows publishers to manage their advertising inventory and sell it via RTB from one platform, while plugging into multiple ad exchanges and demand partners at the same time.
The difference between SSPs and ad exchange platforms
We define an SSP as a platform that helps publishers monetize and manage their inventory. We define an ad exchange as a platform that allows publishers and app developers to sell inventory on an impression-by-impression basis on real-time bidding (RTB) auctions.
We define an SSP as a platform that helps connect publishers to advertiser demand and manage their inventory. We define an ad exchange as a platform that allows publishers and app developers to sell inventory on an impression-by-impression basis on real-time bidding (RTB) auctions, drawing on multiple demand sources to lift fill rates and yield.
Within the broader advertising ecosystem, the two roles increasingly overlap, many SSPs incorporate ad exchange functionality, and vice versa. The result is that publishers get access to broader demand from a single integration, and the programmatic advertising ecosystem has consolidated around fewer, more capable platforms.
Top supply side platform companies
AdColony
One of the largest mobile advertising platforms globally, reaching more than 1.5 billion users. Acquired by Digital Turbine in 2021 for approximately $400 million and now operates within Digital Turbine’s mobile growth platform.
Adform
The only global, independent, fully integrated advertising platform built for modern marketing. Its Adform FLOW infrastructure now extends to agentic advertising workflows, with the company positioning itself as an independent alternative to walled gardens.
Admixer
An independent ad tech company developing a full-stack programmatic ecosystem with customizable technology for publishers, agencies, and ad networks.
Adspruce
Mobile video monetization platform helping publishers deliver rich media video campaigns across mobile devices.
Axonix
Telefónica-owned mobile-first ad exchange specializing in audience trading with first-party telco-verified data sets.
Equativ
One of the largest independent global ad platforms following its 2024 merger with Sharethrough, which itself absorbed District M in 2021. Operates an ad server, SSP, DSP, curation tools, and CTV ad insertion, with majority ownership held by Bridgepoint Group.
ExoClick
Specialized ad exchange supporting 20+ ad formats with optimized targeting, behavioral retargeting, and big data analytics.
FreeWheel
A leading premium video and CTV ad platform serving publishers, broadcasters, and distributors. Dominant in CTV supply with deep integration into Comcast’s broader media stack.
Fyber
Mobile monetization platform combining mediation, RTB, video, and audience segmentation. Acquired by Digital Turbine in 2021 and now operates as “Fyber by Digital Turbine.”
Geniee
Japan’s top-tier ad platform helping publishers maximize revenue through programmatic monetization across web and mobile.
Google Ad Manager
Google’s complete platform for publishers to manage and grow digital ad revenues across formats and devices.
GumGum
Global contextual advertising technology company specializing in contextual intelligence across text, image, and video. A leading independent player in the post-cookie contextual space.
Index Exchange
Global advertising marketplace where premium digital media companies transact ad impressions with accountability. One of the few remaining independent, large-scale exchanges.
Kargo
Omnichannel SSP focused on premium publisher inventory, mobile, and CTV. Significantly expanded its footprint through acquisitions including Forbes Marketplace and parts of Vistar’s display business.
Magnite
The world’s largest independent sell-side advertising platform after a series of mergers, Rubicon Project + Telaria (2020), SpotX (2021), and SpringServe (2021). Heavily focused on CTV with its Magnite Streaming platform.
Mintegral
Global mobile advertising platform driven by AI, providing user acquisition, monetization, and creative solutions for mobile app publishers.
Nexxen
End-to-end advertising platform unifying DSP, SSP, ad server, and data capabilities. Rebranded from Tremor International in 2023 after absorbing Unruly (acquired 2022) and Amobee (acquired 2022).
OpenX
Independent ad exchange focused on reaching consumers at scale across fragmented media. One of the longest-running independent players in the space.
Perion
Parent company of Hivestack (DOOH), with a broader portfolio across DSP, SSP, and retail media. Active acquirer in the consolidation cycle.
Primis
Video discovery and monetization platform for publishers, with video player technology from Cedato (acquired 2019).
PubMatic
Independent technology company enabling publishers and app developers to control and maximize their advertising businesses across formats and devices. One of the few publicly traded pure-play SSPs.
PubNative
Mobile publisher platform and programmatic exchange offering monetization solutions via API, SDK, and JavaScript. Operates within Verve Group’s broader ad tech portfolio.
PulsePoint
Healthcare-focused programmatic platform delivering personalized information to clinicians and patients with HIPAA-aware infrastructure.
Setupad
Header bidding and publisher monetization platform helping smaller and mid-size publishers join the programmatic ecosystem.
Sonobi
Independent technology company providing a transparent media marketplace focused on individual-based, rather than impression-based, advertising.
Sovrn
Publisher technology company providing products and services for tens of thousands of online publishers, including SSP and header bidding capabilities.
Tappx
AdTech company delivering digital advertising solutions across mobile, OTT/CTV, and desktop, with a focus on app developer monetization.
Teads
End-to-end omnichannel advertising platform for the open internet, combining Outbrain’s performance technology with Teads’ video and branding capabilities. Combined entity reaches 2 billion+ consumers per month across 50+ markets and operates under the Teads name.
Xandr
Acquired from AT&T by Microsoft and integrated into Microsoft Advertising. Microsoft has been deprioritizing the third-party SSP side of Xandr (legacy AppNexus), focusing instead on its owned-and-operated inventory and the Netflix CTV partnership.
Yieldmo
Curated marketplace and creative ad platform focused on attention-based, high-impact formats. One of the cleaner examples of where SSPs are heading: curated, outcome-accountable supply.
Zelto
Full-stack programmatic monetization for web publishers, including AdPushup, AdRecover, and Glimpse.
FAQ
Final thoughts
The middle layer of programmatic used to be crowded. Now it’s contested. Buyers want fewer hops between their spend and the impression. Regulators want clearer answers on data. Publishers want demand they can trust, not just demand at scale. The SSPs that hold their ground in the next few years will be the ones that earn their place in every transaction.
Selecting the right SSP has become a strategic decision. The platforms that provide publishers with transparent paths to demand and outcome-aligned partnerships will be the ones publishers stay with.
Avenga works with publishers, ad networks, and AdTech vendors on the engineering behind that choice. Start a conversation.
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