Question 1

What does this converter change?

Accepted Answer

The video codec. H.265 to H.264 uses libx264. H.264 to H.265 uses libx265 and an hvc1 tag.

Question 2

Is this a remux?

Accepted Answer

No. It re-encodes. For a raw .h264 dump, use H.264 to MP4.

Question 3

Does the video leave my device?

Accepted Answer

The encode runs in the tab after FFmpeg WASM loads.

Question 4

What happens to audio?

Accepted Answer

It is written as AAC at 128k.

Question 5

Can I set a bitrate?

Accepted Answer

Quality is CRF. There is no custom bitrate field.

Question 6

Why did a large file fail?

Accepted Answer

Browser memory. Long or high-resolution clips can OOM. Keep the original.

Question 7

Is this a place to download movies?

Accepted Answer

No. You supply the file you already have the right to convert.

Question 8

Will every player play the HEVC result?

Accepted Answer

No. H.264 is the compatibility direction. HEVC often needs a newer player.

Question 9

Are originals overwritten?

Accepted Answer

No. You download a new file.

Question 10

Should I compress instead?

Accepted Answer

Yes, if you want a smaller file and the codec can stay the same.

Question 11

Does this work offline after load?

Accepted Answer

After FFmpeg WASM is present. First load still needs that build.

H.265 to H.264 Converter - Re-encode Video in the Tab