What is SSAI?

Updated September 2026 · Reviewed by the Flicknexs platform team

Quick answer

SSAI (Server-Side Ad Insertion) is a method where the ad server stitches ads directly into the video stream before it reaches the player. The viewer sees a single continuous file, which hides the ad logic from the client and simplifies tracking for operators.

Key takeaways

  • The ad is part of the video file, not a separate request from the player.
  • Reduces the risk of ad blockers and client-side errors.
  • Simplifies analytics because the server logs the exact ad served.
  • Requires a capable ad server and compatible player support.

How SSAI works

In a standard video delivery setup, the player requests a video stream. With SSAI, the request also includes ad parameters. The ad server checks the viewer's profile and context, selects the appropriate ad, and stitches it into the video stream at the designated cue points. The player receives a single, continuous media file. It does not know an ad is present; it just plays the stream.

This process happens on the server side. The client player remains simple. It does not need to handle complex ad logic, VAST parsing, or timing adjustments. The server handles the heavy lifting of selecting and inserting the creative. This separation of concerns keeps the player lightweight and consistent across devices.

  • Request: Player asks for video with ad parameters.
  • Selection: Ad server picks the right creative based on rules.
  • Stitching: Server combines video and ad into one stream.
  • Delivery: Player receives and plays the combined stream.

Why SSAI matters for a streaming business

SSAI solves two major problems for operators: ad blocking and data accuracy. Because the ad is embedded in the video file, standard ad blockers that intercept network requests often fail to detect it. This protects your ad revenue from being stripped out before the viewer sees it.

Data accuracy is the second benefit. When the player handles ads, you rely on client-side reports to know if an ad played. These reports can be lost or inaccurate. With SSAI, the server logs every ad impression. You know exactly which ad was served to which viewer, at what time, and on which device. This clean data is essential for proving value to advertisers and optimizing your inventory.

For FAST channels, SSAI is often the default approach. It allows you to serve different ads to different viewers within the same live stream without changing the player code. It keeps the viewing experience smooth and the revenue stream reliable. If you are building an ad-supported platform, SSAI reduces the technical debt associated with client-side ad management.

SSAI vs CSAI

SSAI and CSAI (Client-Side Ad Insertion) are two ways to deliver ads. The core difference is where the ad is stitched into the video.

In CSAI, the player receives a video stream with ad markers. The player then makes a separate request to the ad server for the creative. It stitches the ad locally. This method is older and more complex for the player to handle.

In SSAI, the server stitches the ad into the stream. The player just plays the file. This is simpler for the client and more secure for the operator.

FeatureSSAICSAI
Ad Stitching LocationServerPlayer
Ad Blocker RiskLowerHigher
Player ComplexityLowHigh
Data AccuracyHigh (Server logs)Variable (Client reports)
Implementation EffortHigher (Server setup)Lower (Player logic)

Common mistakes with SSAI

Operators often make a few key errors when implementing SSAI:

  • Ignoring Cue Points: If your SCTE-35 markers are misaligned with the video content, ads will appear at awkward moments. Test your cue points thoroughly.
  • Overlooking Latency: SSAI adds a step to the delivery chain. If your ad server is slow, it can increase initial load times. Monitor your server response times.
  • Assuming All Players Support It: Not all players handle SSAI streams the same way. Test on all your target devices, including smart TVs and mobile apps.
  • Neglecting Fallbacks: If the ad server fails, you need a plan. Make sure your system can serve the video without ads if the ad request times out.

How Flicknexs handles SSAI

Flicknexs includes SSAI as a core capability. The platform stitches ads into the video stream on the server side, keeping your viewers see the ad as part of the content. This setup works with your existing ad server integrations. You can manage ad rules and targeting through the platform's advertising tools. The player receives a clean stream, reducing the burden on client-side code. This approach supports your FAST channels and on-demand content with consistent ad delivery. It helps you protect revenue from ad blockers and provides accurate impression data for your reports. For details on setting up ad-supported channels, see Launch a FAST channel.

Launch a FAST channel

Done reading about SSAI?

Flicknexs ships it as part of a white-label streaming platform: web, mobile and TV apps, billing, ads, DRM and playout, on your own domain.

SSAI FAQ

Yes, SSAI is commonly used for live streams. The server stitches ads into the live feed as it is delivered. This allows for real-time ad insertion based on viewer context. It is a standard method for FAST channels and live sports or news streaming.
It is harder for ad blockers to stop SSAI because the ad is part of the video file. Standard blockers that intercept network requests may not detect the ad. However, sophisticated blockers that analyze video content can still potentially interfere, though this is less common than with CSAI.
You need an ad server that supports SSAI. This can be a third-party service or an integrated solution. The ad server selects the creative and sends it to the video server for stitching. Flicknexs integrates with various ad server setups to handle this process.
SSAI may have higher server-side costs due to the processing required for stitching. However, it often reduces player development costs and improves ad revenue protection. The total cost depends on your scale and the specific ad server you choose. Many operators find the revenue protection worth the cost.
SSAI stitches ads into the video stream on the server before it reaches the player. Client-side insertion swaps ads locally in the browser or app. SSAI hides the ad switch from the user, preventing buffering hiccups and making it harder for blockers to detect and remove the content.
The server fetches live ad data from your ad server in real time. It stitches these ads into the live stream as it plays. This allows dynamic ad insertion based on user profiles or geo-location without interrupting the live broadcast for viewers.

Standards and references

Further reading

SSAI (Server-Side Ad Insertion): How It Works for OTT