Downloaded YouTube videos tend to run into three problems. The service lists nothing above 720p. A 1080p file arrives without sound. A 4K clip downloads fine, but the player shows a black screen, stutters or refuses to open it at all. All three have the same root: YouTube does not store a video as one file but as a set of separate streams in different codecs. Below we explain how that works, which player handles what, and how to check the real resolution of a file. If you simply want to download a clip in Full HD or 4K, that is done on the YouTube 1080p and 4K page.
How YouTube stores video
For every clip YouTube keeps dozens of variants: picture without sound at every resolution from 144p up to the maximum, and sound without picture at several bitrates. The player in your browser picks a matching pair and joins them on the fly. This scheme is called DASH.
YouTube used to keep "ready-made" files as well, with picture and sound together: 360p and 720p. Those were what simple downloaders and browser extensions handed out, hence the familiar 720p ceiling. Today that reserve is almost gone. On October 3, 2026 we checked three public videos with yt-dlp 2026.08.19, including Rick Astley's "Never Gonna Give You Up". None of them had a single format with video and sound together: YouTube no longer serves the ready 720p file (the so-called itag 22), and the 360p file with sound (itag 18) is not offered to every client, and in this check it was not offered to ours. So even 720p now has to be assembled from two streams.
Here is what YouTube stores for the Rick Astley clip, which runs 3 minutes 33 seconds. The sizes are for the video stream without sound; the sound adds about 3.3 MB.
| Resolution | H.264 | VP9 | AV1 |
|---|---|---|---|
| 720p | ≈ 25 MB | ≈ 17 MB | ≈ 17 MB |
| 1080p | ≈ 77 MB | ≈ 29 MB | ≈ 29 MB |
| 1440p (2K) | none | ≈ 144 MB | ≈ 117 MB |
| 2160p (4K) | none | ≈ 342 MB | ≈ 229 MB |
The table shows two things. First, H.264, the most compatible codec, exists only up to and including 1080p. Second, every step above 720p is several times heavier than the one before, and merging and sending such files puts real load on a server. That is why many services keep the free tier at 720p, Skachok included; what the paid plans cover is on the pricing page.
Why 1080p arrives without sound
The most common reason: the service passed you the video stream as is and did not add the sound. The file really is 1080p, it just has no audio track. You can fix it yourself if you download the matching audio separately, for example with ffmpeg: ffmpeg -i video.mp4 -i audio.m4a -c copy out.mp4. It is easier to use a service that joins the streams on its side: Skachok does it for every quality, so the sound is there in 720p and in 4K alike.
Less often the file does have sound, but the player won't play it. YouTube stores audio in two variants, AAC and Opus, and some older players and TVs understand only AAC. Opening the file in VLC settles it.
Codecs: why 4K won't open
The container can be the same, MP4, while the codec inside differs. The difference between a container and a codec is explained in detail in the article on MP4, WebM and MKV.
H.264 plays in any player, phone and TV from the last fifteen years. At every resolution Skachok picks H.264 when YouTube stores it, so 1080p and below open everywhere.
VP9 and AV1 compress better but are not supported everywhere. For 2K and 4K there is no alternative: YouTube does not store H.264 at those resolutions, and the file arrives as AV1 or VP9 inside an MP4.
Who handles what:
- VLC and MPV on computers and phones play all three codecs. That is the quickest way to open any downloaded file.
- Chrome, Edge and Firefox also open VP9 and AV1: you can drag the file straight into a browser window.
- Movies & TV and Media Player on Windows show a black screen or an error without the right extensions. Both are free in the Microsoft Store: VP9 Video Extensions and AV1 Video Extension.
- The Photos app on iPhone and iPad does not open VP9, and only the iPhone 15 Pro and newer models decode AV1 in hardware. On other models install VLC for iOS or download the clip in 1080p.
- TVs depend on the model: most recent smart TVs have VP9, AV1 mostly appears on models from 2021 onward. If in doubt, check the specs or take 1080p.
If 4K opens but stutters, the computer usually has no AV1 hardware decoder and the processor can't keep up. Switching to 1440p or 1080p helps.
Symptom, cause and fix
| Symptom | Cause | What to do |
|---|---|---|
| Nothing above 720p in the list | The service takes only ready formats or limits its free tier | Download on the 1080p and 4K page |
| Not even 720p, only 360p | The downloader was built around the old itag 22 format | Use a service that merges streams |
| 1080p without sound | You got the video stream without audio | Merge it with audio in ffmpeg or download again with merging |
| 4K: black screen, sound plays | The player doesn't know VP9 or AV1 | VLC or the Microsoft Store extensions |
| Won't open in Photos on iPhone | VP9 unsupported, AV1 only on newer models | VLC for iOS or 1080p |
| 4K stutters | No AV1 hardware decoder | 1440p or 1080p |
| "1080p" looks soft | The author uploaded 720p and the file was upscaled | Check the resolution, see below |
How to check the real resolution and codec
The file name and the label in a list prove nothing: a "1080p" file is sometimes stretched from 720p. The real numbers are in the file's properties.
- Windows. Right-click the file → "Properties" → "Details" tab. The "Video" section lists the frame width and height: 1920 × 1080 for Full HD, 3840 × 2160 for 4K.
- macOS. Select the file in Finder and press Cmd+I: the dimensions and codecs are under "More Info".
- VLC. Open the video and choose "Tools" → "Codec Information" (Ctrl+J). It shows both the resolution and the codec: H264, VP9 or AV1.
- Android. Open the clip in Google Photos and swipe up: the details list the resolution.
- iPhone. Open the video in Photos and tap the "i" button or swipe up: you will see the resolution and file size.
For vertical video the sides swap: 1080 × 1920 is also 1080p. Skachok lists only the resolutions a clip really has. If the author uploaded the video in 720p, 1080p won't appear there.
FAQ
Why do free services give YouTube only in 720p?
Historically 720p was the highest quality YouTube kept as a single file with sound. That file is gone now, and everything above 360p has to be assembled from two streams. 1080p and 4K files are several times heavier, so many services keep their free tier at 720p.
Why won't my downloaded 4K video open?
Most likely it is in AV1 or VP9: YouTube does not store H.264 in 4K. Open the file in VLC, install VP9 Video Extensions and AV1 Video Extension on Windows, or download the clip in 1080p.
Can I get 4K in H.264?
Only by re-encoding, for example in HandBrake. The quality won't improve, the file will get bigger, and converting 4K takes a while. If you need compatibility, it is simpler to download 1080p.
How do I tell which codec a file uses?
Open it in VLC and press Ctrl+J: the "Codec" line says H264, VP9 or AV1. On a Mac the same is visible in Finder via Cmd+I.
Why did my video download without sound?
The service handed you the video stream without an audio track, or the player doesn't understand the audio codec. Merge the streams yourself in ffmpeg or download the clip again from a service that joins them.