Speed Test
Zuno’s Speed Test measures how quickly your device can read an original media file from your server. It is available to everyone on iPhone, iPad, Mac and Apple TV, with Plex, Jellyfin and Emby.
The result describes the connection to your media server. An internet speed test measures a different connection and may give a very different result.
Run a test
Section titled “Run a test”- Open Settings → Sources & Servers and select your server.
- Open Speed Test. Zuno automatically chooses a file from that server.
- Select Start Test.
On Apple TV, the test opens full screen with Start Test beside the results panel. Choosing a file prepares the test; the transfer begins when you select Start Test. The graph and readings stay visible during and after the test.
You don’t need to choose a movie or episode yourself. The Test file label shows the selected file and changes to Testing with… during the transfer. Change File or Version, when available, lets you choose another candidate or another version of that file.
Stop playback and pause downloads before testing so they don’t compete for the same connection. The server must be enabled and connected.
The transfer runs for up to 20 seconds and stops after 1 GiB of data, plus a small amount already in transit, or when the file ends. It may use mobile data. The file is not saved, nothing is played, and your watch progress and playback quality settings are unchanged.
You can cancel at any time. Leaving the test screen or sending Zuno to the background also cancels a running test.
Test a title that is buffering
Section titled “Test a title that is buffering”Open the movie’s details and choose Test Streaming Speed from the … menu. On Mac, use the speedometer action in the toolbar. An episode’s details also offers a speedometer action, or a Test Streaming Speed button on Apple TV.
If you have selected a version, Zuno tests that version on its own server. This is useful when one title buffers but others play normally: files on the same server can live on different drives or storage systems.
Read the results
Section titled “Read the results”- Average: data transferred divided by the elapsed transfer time, in Mbps. Periods when the transfer stalls are included.
- Current: speed during the most recent sampling interval, approximately one second.
- Lowest: the lowest speed among those full sampling intervals. Repeated dips are more informative than a single isolated dip.
- Graph: how transfer speed changes during the test. A steady connection is preferable to repeated drops to very low speeds.
- Time to first byte: how long the request took to begin receiving file data. This is separate from the average transfer speed; it isn’t a ping measurement.
- Connection: local, remote or Plex relay when Zuno knows the route. Some addresses appear as Connection type unknown.
If the transfer finishes before the first full sampling interval, Zuno still shows its average speed, duration and data transferred. Current and lowest speed show a dash because there is no full interval to report.
When you test a specific title and its bitrate is available, Zuno compares the transfer speed with that bitrate. A sustained average below the file’s bitrate suggests buffering; extra headroom helps accommodate bitrate peaks and speed dips. A short run of less than five seconds does not receive a playback assessment.
A good result does not guarantee smooth playback. Server playback policies, decoding, audio, subtitles and bitrate peaks can still cause problems. The test also includes the server’s storage performance and cannot identify the exact cause of a slow transfer by itself.
Retry or share
Section titled “Retry or share”Use Test Again to compare results after changing your connection, or choose another test file. Cancelled and failed runs are labelled as partial results; runs ending at the data limit or end of the file say why they stopped.
On iPhone, iPad and Mac, Share Results exports a text summary with speeds, duration, connection type and completion status. It excludes media titles, server addresses, authentication tokens and custom headers. On Apple TV, read the result directly from the test screen.
If Zuno’s automatically chosen file is missing or empty, it tries another candidate. Authentication and connection failures are shown directly. If no suitable file is found, try the test from a movie or episode’s details.
See also
Section titled “See also”Plex is a trademark of Plex, Inc. Jellyfin and Emby are trademarks of their respective owners. Dolby, Dolby Vision, and Dolby Atmos are trademarks of Dolby Laboratories. Zuno is not affiliated with or endorsed by these companies.