What is Video Start Time (VST)?

The time it takes an app to begin playing any content after the user interacts with the “Play” button is known as the “Video Start Time” (VST). In simple words, the amount of time that is taken between the user interaction with play and the display first frame of video.

Generally, VST is calculated in seconds for the OTT platforms, where a longer duration often leads to user drop-offs. A shorter VST indicates a more seamless watching experience.

The importance of Video Start Time (VST) in OTT Applications

1. User Experience and Retention: Whether you are binge-watching a series, watching a live match, or watching a favorite movie, any delay during the playback can cause frustration, and the user is more likely to drop. A good VST ensures that the playback experience is seamless
2. Advantage over competition: With so many applications on OTT markets, having good content alone is not enough. Performance is a key parameter. Platforms that constantly deliver playback with low VST outperform competitors in terms of user engagement, watch time, and overall retention.
3. Influence on Revenue: A poor playback experience can lead to subscription cancellations and, for AVoD (Ad-supported Video on Demand), even a delay of one second reduces the chance of an ad being viewed.
4. Device and Network Fragmentation: OTT apps run on various types of devices: Smart TVs, Mobile, and web across various network conditions. A low VST represents that the platform is properly optimised to handle these various environments to deliver consistent playback behaviour.

Factors that affect VST

1. Content Delivery Network Performance: A Faster CDN can reduce buffer and latency
2. Adaptive Bitrate Streaming (ABR): Selecting the right initial bitrate impacts how quickly the first frame appears
3. Player Optimisation: An optimised video player can cut milliseconds from start-up time.
4. Encoding & Packaging: Segment size and codec selection directly affect load times.
5. Network Condition: VST increases due to high latency, packet loss, or poor bandwidth.

How to optimise VST on OTT Platforms?

1. Pre-fetching & Smart Caching: Before the playback begins, the app pre-loads the first few video segments in advance. Therefore, when a user interacts with the play button, playback starts immediately instead of waiting for the first chunk to load.
2. Optimised Start-Up Bitrate: Platform shall begin playing the content with a lower bitrate that loads quickly, and once the playback is smooth, the quality automatically improves as bandwidth allows.
3. Multi-CDN Strategy: By routing requests to the nearest and fastest server, the platform aims to minimise the latency and buffering, or long start time.
4. Player Enhancements: The OTT player shall be engineered to be lightweight and efficient. Features like faster decode pipelines and adaptive algorithms help reduce start time while maintaining smooth playback.
5. Monitoring & Analytics: Use of real-time monitoring tools to track the VST across devices, networks, and geographies. Any spike in delays will help engineers to quickly identify bottlenecks at the earliest.

Conclusion

Video Start Time is more than a technical metric – it is a critical KPI for OTT platforms. A faster VST means a happy user, longer watch time, and higher revenue. In a highly competitive market, optimising VST is not optional; it is an essential.

OTT providers that make VST optimization a priority always lead in delivering a seamless and enjoyable streaming experience.