The result panel tells you which case you are in before you save anything: it names every track the parsers returned. If a video column and an audio column both appear, you have a choice to make rather than a fault to hunt.
Cause 1: a video-only track was saved
This accounts for the large majority of silent downloads. When a platform serves renditions, the video-only tracks genuinely contain no audio, and saving one produces a file that is exactly as mute as its label says.
- Two columns in the result panel means two selections are needed
- A merged file is one MP4; two saved tracks are two files that stay separate
- The fix is to parse the link again and select one track of each kind
Cause 2: the codec could not go into an MP4
SniffVid never transcodes, so a merge is only possible when both streams already fit the MP4 container. When they do not, the merge is refused and the message names the codec involved — that is a real limit rather than a failure you can retry away.
Cause 3: the source served a silent stream
Some platforms mute audio for anonymous visitors, usually for licensing reasons on music content, and some audio tracks are restricted to a region. In that situation no downloader can add sound, because the sound was never handed over.
- A muted source track stays muted in the downloaded file
- Region-restricted audio may be missing while the picture resolves normally
- Retrying later can help, because parser coverage and platform behaviour change
Cause 4: the file was still being written
An interrupted save, a full disk or a live stream that had not finished can all produce a file whose index does not describe a complete track. These files usually play for a moment and then stop, or refuse to play at all.
Checking the file before blaming the download
Two minutes of checking saves a lot of guessing, and it separates a source problem from a local one.
- Compare the saved size with the track sizes the result panel reported
- Play the file in a second player, so a single app's decoder is ruled out
- Open the file's details to confirm it contains both a video and an audio stream
Reference
These tables are shared across the site, so a figure you saw on one page is the figure you see here.
| What you see | Likely cause | What to do |
|---|---|---|
| The file plays, but there is no audio at all | A video-only track was saved | Parse again, select a track in the audio list as well, then merge. |
| No merge button appeared | Only one kind of track came back | The source returned a single finished file, so there is nothing to merge. |
| The merge failed and named a codec | That codec cannot go into an MP4 container | Nothing to retry — SniffVid never transcodes. An editor can re-encode if you need one file. |
| The file plays for a second and stops | The save or the merge was interrupted | Check the free space on the device, then parse the link and save it again. |
Background and edge cases
How to tell the four causes apart in under a minute
The result panel separates them before you save, and the file itself separates the rest. Start with what the panel showed, then play what you got in a second player — that alone rules out a local decoding problem and points at either the source or the save.
- Two lists and one selection: the cause is a video-only save
- One file, no audio entry: the source never published sound separately
- A codec named in an error: the streams cannot share an MP4 container
Why some music videos are silent everywhere
A rights holder can license a track for on-platform playback without licensing it for download, and the practical result is that the platform hands anonymous visitors a silent video. This is a rights decision upstream of any tool, so it is not something a downloader can or should work around.
- The same upload may carry sound in one region and none in another
- A track that was audible last month can be muted without the video changing
- Parsing again later can help, because what a parser can reach changes over time
Checking a file before blaming the download
Compare the saved size with the track sizes the panel reported. A file close to the sum of two tracks almost certainly has both; one close to the video track alone almost certainly does not. That check takes seconds and settles which of the four causes you are looking at.
- The panel reports a size per track, so there is a number to check against
- A second player rules out a decoder problem in the first one
- File details will list the streams inside, which is the definitive answer