Sure, CloudConvert is awesome.

But have you considered these open source alternatives?

They are free, self-hostable and community-driven.

Check by yourself:  Vert .

  1. So is Vert

    File converter (images, audio, video, docs)

    ★ 1.9K Conversion License: AGPL-3.0

    The next-generation file converter. Open source, fully local and free forever.

    All image and audio processing is done on your device. Videos are converted on our lightning-fast servers. No file size limit, no ads, and completely open source.