CSAI vs SSAI: What’s the Difference?

Blog 5 min read | Jan 19, 2024 | Filip Trichkov


The battle for viewer attention has made way for innovative technologies to seamlessly integrate advertisements into the streaming experience. The two most prominent players in this field are CSAI (Client-Side Ad Insertion) and SSAI (Server-Side Ad Insertion). Understanding the similarities and differences between these approaches is important for content providers aiming to strike the perfect balance between user experience and revenue generation.

What are CSAI and SSAI?

CSAI (Client-Side Ad Insertion)

As the name suggests, Client-Side Ad Insertion involves the insertion of ads on the viewer’s device i.e. on the client side. In this case, the ad content and tracking are handled by the client’s media player.

More control over ad delivery is given to content providers with CSAI. The ads are fetched, processed and played by the viewer’s device, giving a personalized touch to the ad experience. Real-time decision-making is allowed by this direct communication between the client and the ad server, enabling dynamic ad insertion based on user behavior and preferences.

Pros and Cons of CSAI

On the positive side, CSAI offers flexibility and customization, allowing for targeted ad delivery. However, this flexibility comes at a cost. Load times and potential buffering issues may appear, impacting the viewer’s experience. On top of that, ad-blockers can be a real threat to CSAI effectiveness, limiting revenue potential.

SSAI (Server-Side Ad Insertion)

Contrastingly, Server-Side Ad Insertion takes place on the server side, where ads are stitched into the content stream before reaching the viewer. The ad content is pre-processed and delivered by the server, ensuring a consistent experience for all viewers.

By eliminating client-side hiccups, SSAI delivers a seamless streaming experience. Since ads are part of the content stream, they bypass ad-blockers, maximizing revenue potential. Additionally, SSAI can provide a smoother transition between content and ads, reducing the risk of buffering interruptions.

Pros and Cons of SSAI

While SSAI excels in delivering a smooth streaming experience, it may lack the detailed  control that CSAI offers. Because all viewers receive the same ad content, personalization takes a back seat. On top of that, since ads are server-stitched, they are harder to measure and track accurately.

The Battle for Viewer Experience

CSAI: Custom Tailoring

One of CSAI’s significant advantages is its ability to custom tailor ads to individual viewers. By making use of real-time data and user behavior, CSAI can deliver personalized ads, which enhances the relevance of the ad and the engagement with it. This approach works well with viewers who appreciate ads that align with their interests.

However, latency issues are a very real concern. Waiting for the client to fetch, process and play the ad can lead to delays, potentially impacting user satisfaction. For a process where every second counts, buffering and load times need to be minimized, or even eliminated.

SSAI: Fluid Flow 

On the other hand, SSAI is excellent in providing a fluid streaming experience. By pre-integrating ads on the server side, content and ads flow seamlessly, which in turn reduces the risk of abrupt transitions that may turn away viewers. In live streaming scenarios where timing is critical, this approach is particularly dominant.

Yet, the consistency of ad delivery comes at a cost. The inability to personalize ads for individual viewers may result in a less engaging ad experience. In an age where consumers crave tailored content, the one-size-fits-all approach of SSAI may fall short.

Approaches to Analytics

Analytics play a pivotal role in the shaping of advertising strategies. CSAI and SSAI have significant differences in their approach to how they track ad performance.


CSAI shines when it comes to analytics. Since the client is actively involved in fetching and playing ads, real-time data can be harnessed for instant decision-making. Content providers gain valuable insights into user behavior, enabling them to adjust their ad strategies on the fly.


SSAI, however, faces challenges in tracking ad performance. The server-side stitching of ads complicates the measurement process. While efforts are made to implement tracking mechanisms, the granularity achieved by CSAI is still unable to be replicated with SSAI. Content providers must navigate this fog of analytics, relying on broader data sets that may lack the precision offered by CSAI.

The Ad-Blocking Problem

Ad-blockers are the unsung heroes for all those users seeking an uninterrupted streaming experience. Both CSAI and SSAI face their unique challenges when it comes to this.

CSAI: Vulnerable to Ad-Blockers

CSAI’s Achilles’ heel is its vulnerability to ad-blockers. Because ads are fetched and played on the client side, ad-blockers can easily intercept and block these attempts. For content providers who rely heavily on ad revenue, this is a considerable threat to their bottom line.

SSAI: The Ad-Blocker Shield

SSAI, on the other hand, is a powerful shield against ad-blockers. By inserting ads on the server side, they become difficult to tell apart from the content stream, avoiding the detection of ad-blockers. This advantage makes SSAI a more reliable revenue generator in a time where ad-blocker usage is on the rise.

Dynamic Ad Insertion: Harmony in Hybrid Solutions

In the battle between CSAI and SSAI, there is no one-size-fits-all solution. Content providers often find themselves at a crossroads between the desire for personalized ad experiences and the need for seamless streaming.

The industry has witnessed a surge in hybrid approaches, combining the strengths of both CSAI and SSAI. This approach, often termed Dynamic Ad Insertion (DAI), seeks to strike a balance between personalization and seamlessness.

By leveraging DAI, content providers can employ CSAI for targeted ad delivery to specific user segments while still embracing SSAI for a consistent streaming experience. This dynamic fusion allows content providers to navigate the complexities of ad insertion, adapting to viewer preferences without compromising on quality.


As the digital streaming world keeps evolving, the choice between CSAI and SSAI remains an important and strategic decision for content providers. Each approach comes with its own set of advantages and challenges, demanding a careful evaluation of priorities and goals.

CSAI’s ability to offer personalized ad experiences and real-time analytics caters to a viewer base seeking individualized content. However, the vulnerability to ad-blockers and potential latency issues necessitate a cautious approach.

On the other hand, SSAI’s seamless streaming experience and immunity to ad-blockers ensure a reliable revenue stream. Yet, the sacrifice of personalized ad experiences and the challenges in tracking ad performance pose their own set of drawbacks.

In this dynamic landscape, the pursuit of a harmonious solution through hybrid approaches like DAI emerges as a eureka moment. The choice between CSAI and SSAI is no longer a binary decision and by embracing the strengths of both CSAI and SSAI, content providers can navigate the complexities of ad insertion much better than before.