Streaming Media Test Test HLS, DASH and Video Streams
Check that your video stream plays smoothly for viewers around the world. This free streaming test downloads your HLS stream or video file from multiple locations and compares download speed with the stream's bitrate.
At a glance
- Formats: HLS (M3U8 playlists, live and on-demand), MPEG-DASH (MPD manifests) and progressive video or audio files over HTTP or HTTPS.
- HLS: downloads up to 4 segments (or 20 seconds of media) of the first quality level and times each one; live streams start near the live edge.
- Metrics: startup time, download speed, bitrate, buffer ratio and total time per location.
- Media details: codec, container, resolution, frame rate and audio, read from the downloaded media.
- Playback verdict: the buffer ratio shows whether the stream downloads faster than it plays.
- Global: test from up to 3 locations at once without an account.
- Free: no sign-up; export results as PDF, CSV or JSON.
How to test a video stream
- Paste the stream URL: an HLS playlist (
.m3u8), a DASH manifest (.mpd) or a media file such as.mp4. Use the stream's raw URL, not the address of the web page with the player. - Select up to three locations near your viewers.
- Click Run Test.
The format is detected from the content, so the URL doesn't need a particular extension.
What the streaming test measures
- Startup time: how long until the first media data arrives, close to what a viewer waits before playback starts.
- Download speed: how fast the media downloads from each location.
- Bitrate: how much data the stream needs per second of playback.
- Buffer ratio: download time divided by media duration. Below 1, the stream downloads faster than it plays and viewers see smooth playback; above 1, viewers will see buffering.
- Segments and quality levels: size, duration and download time of each HLS segment, and the available renditions with bandwidth, resolution and codecs.
How each format is tested
| Format | What is downloaded | What is checked |
|---|---|---|
| HLS (M3U8) | Playlist, init segment and up to 4 media segments (max 20 s or 20 MB) of the first variant | Startup, speed, bitrate, buffer ratio, codecs |
| MPEG-DASH (MPD) | The manifest only | Representations: bandwidth, resolution, codecs, frame rate |
| Progressive file | The first 8 MB | Startup, speed, bitrate, codecs |
RTMP and RTSP URLs are not supported; test the HLS or DASH output of your streaming server instead. Codec details can't be read from encrypted HLS streams.
Why streams buffer in some regions
If the buffer ratio is above 1 in one location but fine in others, the CDN edge or the network path to that region can't deliver the bitrate. Options are adding a lower-bitrate rendition to your HLS ladder, checking CDN coverage for that region, or reducing segment sizes. If the stream is slow everywhere, the origin or packager is the bottleneck.
Related free tools
- Web Server Test: check the response time of the server that hosts your playlist or player page.
- Traceroute Test: find where latency builds up on the path to your streaming server.
To monitor live streams 24/7 with alerts, see Dotcom-Monitor. To load test a stream with thousands of concurrent viewers, see LoadView.
Frequently asked questions
How do I test an HLS stream?
Paste the M3U8 playlist URL and run the test. Each location downloads the playlist and the first media segments, then reports startup time, download speed, bitrate, buffer ratio, codec and resolution.
What is a good buffer ratio?
Below 1 means the media downloads faster than it plays, so playback is smooth. A ratio of 0.5 or lower leaves comfortable headroom. Above 1, viewers at that location will see buffering.
Can I test a live stream?
Yes. For live HLS playlists the test starts near the live edge, with the last three segments, the way players do, and measures how quickly they download.
Does the test support RTMP or RTSP?
No. The test supports HLS, MPEG-DASH and media files over HTTP or HTTPS. Test the HLS or DASH output that your viewers' players use.
Why can't the test find my stream?
Usually because the URL is the web page with the player, not the stream itself. Open your browser's developer tools, find the .m3u8 or .mpd request in the Network tab, and test that URL.
Which quality level does the HLS test use?
The first variant listed in the master playlist, which is the one most players start with. The result also lists all available quality levels.
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