DASH — Dynamic Adaptive Streaming over HTTP, formally MPEG-DASH — is the codec-agnostic, open-standard adaptive streaming protocol. Standardised by MPEG in 2012, DASH chops video into short segments (typically 2–10 seconds each), publishes a manifest file (MPD — Media Presentation Description) listing the segments at multiple bitrates, and lets the player pick whichever bitrate fits the current network conditions. As the viewer's network changes, the player switches up or down the ladder without interruption.
DASH was designed deliberately as an open alternative to Apple's proprietary HLS, and the two protocols dominate the adaptive-streaming world together. The technical differences are small — both ship fMP4 segments now (since CMAF), both use HTTP, both support adaptive bitrate switching — but the operational differences matter. HLS is mandatory for iOS Safari and Apple TV apps because Apple doesn't permit anything else. DASH dominates everywhere else — Android, web browsers (except Safari), smart TVs, set-top boxes, gaming consoles. Most streaming products ship both because supporting Apple devices requires HLS while supporting cost-efficient delivery elsewhere benefits from DASH's openness.
For a product team in 2026, DASH is the open foundation for streaming everywhere except Apple devices. Combined with CMAF, the same encoded segments serve both HLS and DASH from the same CDN, with only the manifest format differing. Common deployment recipe: encode in H.264 + HEVC + AV1, package as CMAF, expose via both HLS and DASH manifests, encrypt with CENC for DRM. Major DASH adopters include YouTube, Twitch, Disney+, BBC iPlayer, and most non-Apple platforms. The streaming KB will cover DASH operations in depth; for the encoding/decoding KB, DASH is mostly relevant as the receiving end of the encoding pipeline.
