MP4 is a container; H.264 and VP9 are codecs
The container packages tracks into one file. A video codec describes how the video track is encoded. The .mp4 extension alone does not identify the video codec or guarantee playback. Audio has its own codec and may be missing from the source.
Which option should I choose?
H.264 is a common starting point for compatibility. VP9 is an alternative when offered, not an automatic quality upgrade. Compatibility depends on your OS, browser, player and hardware. SaveMySave shows choices based on source metadata; preparing a choice can still fail if the source changes.
- Check which codecs are offered after the link is analyzed.
- Choose the available resolution you need, up to the current 1080p preview limit.
- Download and test the file in your intended player, including its audio.
More pixels do not restore missing detail
A 1080p label describes resolution, not overall image quality. Bitrate, source compression, frame rate and the original recording also matter. The current workflow does not promise upscaling, a source master or lossless output. A lower resolution may be a better fit for a small screen or limited storage.
The file will not play, or has no sound
First confirm that the browser completed the transfer. Try an available H.264 choice or another compatible player. If the original has no sound, a format change cannot create it. If the original has sound but the completed result does not, treat that as a playback or download defect to investigate, not expected success.
Physical-device playback certification is still pending. No universal device or audio compatibility claim is made.
Quick answers
Is VP9 always smaller or better?
No. The size and quality depend on the actual streams and encoding settings. Compare the available results rather than the codec name alone.
Can I select 4K?
The current preview's selection ceiling is 1080p, and available resolutions also depend on the source. It does not advertise 4K downloads.
Why is only one codec shown?
A source may expose only one usable option. The selector does not invent unavailable formats.