AVPrep | JeffAPierson.com

Convert format

Pick a preset, or set the container and codecs yourself. Remux copies the existing streams into a new container without re-encoding, which is instant and lossless when the codecs are compatible.

Preset

Container

Video codec

Audio codec

Video

Resolution

Frame rate

Quality (CRF 23)

Encoder speed

Audio

Bitrate

Sample rate

Channels

Volume adjust

Trim (optional)

Start

End

Carry existing metadata tags into the output Move MP4 index to the front so the file streams before it finishes downloading

Shrink to a target size

Give a size ceiling and AVPrep works backwards from the duration to a bitrate that lands under it. Useful for a 25 MB email limit, a 10 MB chat upload, or a records request portal that rejects anything larger.

Target by

Target size (MB)

Common limits

How to spend the budget

Audio bitrate to reserve

Resolution

Video codec

Encoder speed

Downmix audio to mono, which frees roughly half the audio budget Re-encode automatically if the first pass overshoots. Skipped when that pass took over three minutes and the miss was small, since a second pass costs as much as the first. Strip video entirely and output audio only

Select a file in the queue to see the bitrate math.

Inspect

Reads the container and stream details plus every tag the file carries. Nothing is changed until you write it back.

No file inspected yet.

Edit tags

Writing tags copies the streams through untouched, so the audio and video quality is identical to the source and the job takes seconds rather than minutes.

Inspect a file first to load its tags.

Custom tags

Job status

Working...

Idle. Nothing running.

Output files

Finished files land here with a download button. They stay in memory only, so save anything you want to keep before closing the tab.