Convert MP4 to Opus on Mac.

Local file processing, by renaming the file in Finder. No converter window and no upload queue.

Finder rename

report.mp4report.opus

How the rename works

  1. 1

    Start with report.mp4

    Put the MP4 file in a folder RenameTo watches, such as Desktop or Downloads.

  2. 2

    Rename it to report.opus

    In Finder, change .mp4 to .opus, then press Return. The rename is the command.

  3. 3

    Find the Opus beside it

    RenameTo produces the requested output and keeps a restorable backup of the original.

What happens under the hood

RenameTo reads the MP4 with the appropriate local macOS media or document framework, then writes a new Opus beside it. The file itself is not sent to a conversion server.

About the formats

MP4 is a broadly supported video container. Opus is a modern codec tuned for efficient speech and audio.

Questions, answered

Does my file get uploaded anywhere?

No. File processing happens on your Mac. RenameTo does use the network for license validation, trial activation, and update checks, but your source files are not part of those requests.

What happens to the original MP4 file?

RenameTo keeps a backup before processing. Undo restores the original alongside a format-changing output and does not delete that output. If the original name is already occupied, the restored copy gets “(restored)” in its name.

Can I convert a whole folder?

Yes. Rename multiple selected files in Finder and RenameTo queues each supported conversion, with a separate result and backup for every file.

Can I run the same conversion from a script?

Yes. The CLI command is: renameto opus *.mp4

Related conversions

Convert MP4 to 3GP

report.mp4 → report.3gp

Convert MP4 to AAC

report.mp4 → report.aac

Convert MP4 to AC3

report.mp4 → report.ac3

Convert MP4 to AIFF

report.mp4 → report.aiff

Convert 3GP to Opus

report.3gp → report.opus

Convert AAC to Opus

report.aac → report.opus

Convert AC3 to Opus

report.ac3 → report.opus

Convert AIFF to Opus

report.aiff → report.opus

Looking for another format? Browse every conversion.