DASH Player & MPD Stream Tester

Paste a DASH or MPD URL and this DASH player loads the manifest, starts playback and reports what the player sees. You get the quality renditions from the manifest, the throughput the player measured, how much buffer is ahead of the playhead, live latency where the stream exposes it, and a log of the events behind a failure.

The point is to answer why a stream misbehaves without opening developer tools and reading raw network requests.

Quality level is the representation currently playing. In Auto mode the player picks it from measured throughput and buffer health, so it changes during playback.

Bandwidth estimate is what the player measured while downloading segments. It is not the bandwidth value written in the manifest, and the two often disagree.

Buffer is how many seconds of media sit ahead of the current position. A buffer that keeps collapsing toward zero is the usual cause of repeated stalling.

Live latency is how far behind the live edge playback is sitting, shown next to the delay the player is targeting.

Dropped frames come from the browser itself and point at decoding or rendering pressure rather than a network problem.

DASH, or MPEG-DASH, is the streaming standard. MPD is the manifest file format that DASH uses to describe a stream. When someone shares an MPD link they are sharing the entry point to a DASH stream. The manifest section above works as a quick MPD analyzer: it reports the structure the player found, so you can check a manifest declares what you expect before blaming playback.

One manifest describes periods, and inside them adaptation sets for video, audio and text. Each adaptation set holds representations, which are the individual quality renditions the player switches between.

Both deliver adaptive streaming over plain HTTP and both split media into segments the player fetches in sequence. DASH is an open standard using an XML manifest and is codec agnostic. HLS came from Apple, uses a text playlist and is the only option on iOS Safari.

Most services publish both from the same source files. If a DASH stream fails it is worth testing the HLS version of the same content to see whether the problem follows the media or the packaging.

A browser applies restrictions a desktop player does not, and any one of them can block a stream that is otherwise fine.

• Cross-origin rules. The stream host has to allow browsers on other sites to read the manifest and segments.
• Codec support. Browsers ship a limited set of decoders. HEVC, Dolby Vision and some audio formats often will not play.
• Mixed content. An HTTPS page cannot load a plain HTTP stream.
• DRM. Protected streams need a key system the browser supports and a licence the viewer is entitled to.
• Segments on another host. The manifest can load while the media sits somewhere that blocks browser access.

Live DASH deliberately plays behind the live edge so there is buffer to absorb network variation. How far behind depends on segment length, the suggested presentation delay in the manifest, and whether the stream is packaged for low latency.

The latency shown here is the player's own measure of its distance from the live edge. It is not glass to glass latency and it does not include capture or encoding time.