What Is Buffering?

Buffering is the practice of preloading and storing a portion of a media file in the buffer or temporary memory of a device. This process enables video, audio, gaming, or other media files to be played smoothly and without jitter or stuttering. Having an advanced supply of video frames, audio samples, or gaming content in memory at all times prevents the playback from being disrupted if there are momentary delays in the rate of streaming transmission. As the media file plays, additional portions of the file are loaded into the buffer to deliver an uninterrupted streaming experience. If a network or internet connection can deliver streaming media as fast as it needs to be played, buffering is not necessary.

Buffering enables video, audio, and gaming files to begin playing before all the content is loaded. By storing enough content in the buffer, streaming apps can continue to play even when the internet connection slows momentarily or is briefly interrupted.

• Slow internet connections. Slow internet download speeds may cause content to buffer too slowly, especially when users are accessing high-definition content. Streaming platforms like Netflix or YouTube recommend that internet or Wi-Fi connections exceed certain speeds, especially when streaming 4K video. Users seeking to improve buffering can run a speed test to determine how fast their network connections are.
• Limited bandwidth. When the rate of content being downloaded approaches the maximum bandwidth of a Wi-Fi signal, the content will buffer more slowly. This may also occur when multiple users are accessing streaming content simultaneously on the same Wi-Fi connection.
• Problems with devices or browsers. Older wireless routers, laptops, modems, computers, or mobile devices may not be able to receive streaming content fast enough to enable sufficient buffering. Some browsers have less capacity for streaming content and may contribute to buffering issues.
• High-definition content. High-definition videos require a larger amount of data to be played (and therefore buffered) each second, potentially causing buffering problems.
• Strain on the network. Outages or network interruptions may affect the bandwidth and speed of internet connections. When too many users are attempting to access the same content, a streaming provider’s network may become overloaded and deliver content more slowly.
• Latency. The distance between a user and the source of the content can contribute to latency, increasing the time it takes for data packets to traverse the internet and load on the user’s device.
• TCP connection problems. Problems with the Transmission Control Protocol (TCP) may cause slow buffering or prevent content from playing at all.

Streaming media is video or audio files delivered to a user’s device via the internet and intended for media playback. Rather than fully downloading and saving a file on the user’s device, streaming enables viewers to consume content immediately by continuously transmitting content without permanently storing it. Streaming content includes video content, audio files, video games, TV shows and movies, YouTube videos, and live streaming of events.

When video streaming or audio streaming media is supplied over the internet, data packets must travel through numerous routers to move from source to destination, and delays may happen at any point in the journey. Buffering is designed to provide a better user/viewer experience by overcoming or accommodating fluctuations in internet speed, network congestion, or latency — the time between a user’s action and an application’s response.

While buffering technology is essential to quality streaming, most users are only aware of buffering when it happens too slowly and playback is temporarily paused to allow more content to be preloaded. For consumers, the term “buffering” has come to mean the wait time that occurs when streaming apps cannot sufficiently buffer content, causing a pause in the playback of content.

Streaming providers may take several steps to stop buffering problems.

• CDNs. Using a content delivery network (CDN) to cache or store content closer to end users can reduce latency.
• Adaptive bitrate streaming. This technology enables streaming services to dynamically adjust the quality of streaming content based on the speed of a user’s internet connection. This technology requires media to be encoded in files with multiple quality levels so that the provider may seamlessly switch between them during playback.
• Network throttling detection. Some internet service providers (ISPs) deliberately slow down or “throttle” internet speeds. Streaming providers may use technology to detect when a connection is being throttled and adjust the quality of the streaming video to prevent buffering issues.
• Compression and encoding. Providers may optimize content by selecting an optimal encoding format to compressing and converting streaming media into formats that work well with different platforms.
• Network optimization. Working with ISPs, streaming providers can optimize connectivity to reduce network congestion. This may involve using dedicated content delivery networks or establishing direct peering connections to improve overall network performance.