--- title: "What Is SSAI? Server-Side Ad Insertion Explained | RentAnOTT" description: "SSAI stitches ads into a video stream on the server, so they play as one continuous stream. See how it works and how it compares with client-side insertion." url: "https://www.rentanott.com/glossary/ssai" markdown_url: "https://www.rentanott.com/glossary/ssai.md" category: "Advertising" updated: "2026-10-05" --- # What is SSAI? SSAI (server-side ad insertion) is a way of delivering video advertising in which the ads are stitched into the stream on the server before it reaches the viewer. The player receives one continuous stream containing both program and ads. ## How SSAI works Markers in the content show where ad breaks fall. When a viewer reaches a break, the stitching service asks an ad server which ads to show that viewer, then rewrites the stream's manifest so that ad segments replace or follow the content segments. The ads are encoded to match the program's quality levels. Each viewer gets their own manifest, so two people watching the same stream can see different ads. ## SSAI vs CSAI With client-side ad insertion (CSAI), the player itself pauses the content, requests an ad and plays it in a separate ad player. It is simpler and supports interactive ads and detailed measurement, but ad blockers can stop the request, and the switch between players can cause a visible pause. With SSAI the ad is part of the stream. Playback is seamless, ad blockers have little to act on, and it works on devices with limited players, such as older smart TVs. Measurement and interactivity are harder, because the player is not aware it is showing an ad unless extra signalling is added. ## When SSAI is the better choice - Live streams and linear channels, where breaks must start and end exactly on time - Television apps, where viewers expect a broadcast-like experience - Services with a significant share of ad-blocking viewers on the web - A wide range of devices that would each need a client-side ad integration ## SSAI on RentAnOTT AVOD is included on every RentAnOTT plan, and advanced advertising, with deeper targeting, frequency control and ad performance reporting, is a $169/month add-on. Ask us on a demo which insertion method fits your apps and ad partners. [See pricing](https://www.rentanott.com/pricing). ## Related terms - [CSAI](https://www.rentanott.com/glossary/csai) — CSAI (client-side ad insertion) is a way of delivering video advertising in which the player on the viewer's device requests each ad from an ad server and plays it itself, pausing the program while the ad runs. - [Dynamic ad insertion](https://www.rentanott.com/glossary/dynamic-ad-insertion) — Dynamic ad insertion (DAI) is choosing which ads to show at the moment a viewer reaches an ad break, individually for that viewer, instead of permanently embedding the same ads in the video file for everyone. - [VAST](https://www.rentanott.com/glossary/vast) — VAST (Video Ad Serving Template) is the industry standard, published by the IAB Tech Lab, for how an ad server describes a video ad to a player. A VAST response is an XML document that tells the player which media file to play and which tracking addresses to call. - [AVOD](https://www.rentanott.com/glossary/avod) — AVOD (advertising-based video on demand) is a streaming model where viewers watch on-demand video for free and the service earns from the ads shown before, during or after it. - [FAST channel](https://www.rentanott.com/glossary/fast-channel) — A FAST channel (free ad-supported streaming television) is a linear channel delivered over the internet that viewers watch for free, with advertising in scheduled breaks. It looks and behaves like a television channel but needs no subscription or aerial. - [Ad server](https://www.rentanott.com/glossary/ad-server) — An ad server is the system that decides which ad to show each time a player or stitching service asks for one, delivers the details of that ad and counts the result. For a publisher it is the control center of an advertising business. - [Mid-roll ad](https://www.rentanott.com/glossary/mid-roll) — A mid-roll ad is a video advertisement that plays in a break partway through the content, in the manner of a television commercial break. It is the main ad position for long-form and live video. - [Fill rate](https://www.rentanott.com/glossary/fill-rate) — Fill rate is the percentage of ad requests that are answered with an ad. If a service requests 1,000 ads and receives 700, its fill rate is 70%. Unfilled requests earn nothing. ## Further reading - [Features](https://www.rentanott.com/features#addons) - [Content monetization platforms compared](https://www.rentanott.com/blogs/content-monetization-platforms) - [OTT revenue calculator](https://www.rentanott.com/tools/ott-revenue-calculator) ## Frequently asked questions ### What does SSAI stand for? SSAI stands for server-side ad insertion. It is also called ad stitching. ### Does SSAI defeat ad blockers? Largely. Because ads arrive as part of the same stream from the same source as the program, there is no separate ad request for a blocker to stop. ### Can SSAI ads be personalized? Yes. The ad decision is made per viewer at each break, so targeting works much as it does with client-side insertion. All 163 terms: [Streaming and OTT glossary](https://www.rentanott.com/glossary). ## Book a demo Tell RentAnOTT what you are launching. The team walks through the platform and maps the path to go-live around your catalog, markets and revenue model. Book a demo: https://www.rentanott.com/contact ## More from RentAnOTT - [Home](https://www.rentanott.com/index.md) — What RentAnOTT is, what every plan includes, and how launch works - [Features](https://www.rentanott.com/features.md) — Every core feature and optional add-on - [Pricing](https://www.rentanott.com/pricing.md) — Platform tiers, apps, add-ons, usage rates and example bills in INR and USD - [Free tools](https://www.rentanott.com/tools.md) — OTT app builder and calculators for streaming revenue, bandwidth, bitrate and pricing - [Insights](https://www.rentanott.com/blogs.md) — All streaming business articles - [Glossary](https://www.rentanott.com/glossary.md) — Definitions of streaming and OTT terms - [Book a demo](https://www.rentanott.com/contact.md) — Talk to RentAnOTT about your launch Full site in one file: https://www.rentanott.com/llms-full.txt