Slow down audio — free online tool

What to know

Slow down starts the multiplier at 0.8 and can go as low as 0.25, which stretches time to four times as long. Because the tool keeps pitch, a slowed voice stays recognizable and an instrument keeps its key.

Length is the original divided by the multiplier. A 90-second clip at 0.75 becomes 2 minutes, at 0.5 it becomes 3 minutes, and at 0.25 it becomes 6 minutes. Below 0.5 the tool chains two atempo=0.5 stages, so 0.25 is built as 0.5 times 0.5.

Common uses are transcribing a fast interview, picking out the words of a lyric, working out a guitar solo and checking pronunciation in a language lesson. For these, 0.75 is often enough to catch each syllable, and 0.5 helps when you need to hear every note of a run.

Slowing far below 0.5 makes the audio sound warbly, because the algorithm has to invent extra material to fill the longer time. Keep to 0.5 or above for speech, and treat 0.25 as a way to find a note rather than a way to listen.

Pair it with the trimmer when you only need one phrase: cut the bar or sentence first, then slow only that piece, so the output stays short and loops easily.