Yes — drop a folder of WebM files in and we extract audio in parallel. Premium users get more parallel workers and no per-file size cap; on a 50-file batch this is the difference between 90 seconds and 8 minutes.
Audio extraction is much faster than video re-encoding — typically 5-15% of source duration. A 1-hour WebM → MP3 finishes in 3-9 minutes on the standard pipeline; a 5-minute video finishes in under a minute.