SSAI (Server-Side Ad Insertion)

What is Server-Side Ad Insertion (SSAI)?

Server-Side Ad Insertion (SSAI) is a streaming technology that enables the dynamic insertion of advertisements into video content directly at the server level, rather than on the viewer’s device. Also known as dynamic ad insertion (DAI), this method allows streaming platforms, content providers, and FAST channel operators to create a single, seamless stream that includes both the video content and the targeted ads—delivered as one uninterrupted experience.

SSAI is especially valuable in Connected TV (CTV) environments, where fragmented devices and varying technical capabilities make client-side ad insertion less reliable and more vulnerable to issues like buffering, latency, and ad blocking.

How does Server-Side Ad Insertion (SSAI) work?

The SSAI workflow begins with separately stored assets—the primary video content and a catalog of ad creatives. When a viewer initiates playback on a CTV device, the streaming platform sends an ad request to an Ad Decision Service (ADS), which returns one or more ads based on targeting criteria such as user location, device type, viewer behavior, or time of day.

These ads are then dynamically stitched into the video stream in real time by the server, creating a single stream that appears continuous to the viewer. This process is known as ad stitching, and it ensures that both the video content and ads are delivered through the same HTTP Live Streaming (HLS) or DASH stream.

Once stitched, the final stream is sent to the viewer’s device, where it is played back like any other piece of content—without requiring the device to handle separate ad loads or additional rendering.

What are the benefits of SSAI in Connected TV?

Server-Side Ad Insertion offers several technical and strategic benefits for streaming platforms and advertisers, particularly in the CTV ecosystem:

Seamless viewer experience: By combining content and ads into a single stream, SSAI minimizes buffering, reduces latency between ad transitions, and avoids disruptive ad loading screens that can occur with client-side methods.

Ad-blocking resistance: Because ads are delivered as part of the main video stream, they are much harder for standard ad blockers to detect and filter—ensuring higher viewability and protecting ad revenue.

Improved targeting and personalization: SSAI supports dynamic ad delivery based on first- or third-party data, enabling platforms to serve relevant, personalized ads that increase engagement and campaign effectiveness.

Consistent cross-device delivery: SSAI ensures that ads render correctly across a wide range of smart TVs, set-top boxes, and streaming devices—regardless of their hardware or software differences.
Scalable monetization: For FAST and AVOD platforms, SSAI is a foundational technology for scaling revenue. It enables unified ad delivery at massive volumes without overwhelming client devices or degrading playback performance.

Centralized measurement and control: SSAI allows platforms to manage ad delivery centrally, supporting advanced analytics and third-party verification tools that provide insight into impression counts, viewability, and performance metrics.

Final thoughts

Server-Side Ad Insertion (SSAI) is the backbone of modern, monetizable streaming infrastructure—particularly in ad-supported environments like CTV and FAST. By seamlessly stitching targeted ads into content streams, SSAI delivers a premium user experience while enabling scalable, data-driven advertising strategies. For publishers, platforms, and advertisers, SSAI is essential for maximizing viewer engagement and ad revenue in a competitive, device-fragmented landscape.