Free Audio Speed Changer

Audio Speed Changer plays back recordings faster or slower for transcription, practice, language learning, and podcast listening at higher efficiency. Journalists skim interviews at 1.25×, musicians loop difficult passages at 0.75×, and students review lectures on tight schedules.

Unlike simple player speed controls in some apps, exporting a new file lets you share the retimed audio or import it into editors. Pitch correction options preserve natural voices at non-unity speeds when enabled.

Time-stretch algorithms in FFmpeg.wasm adjust tempo via atempo filters for moderate factors or chained filters for wider ranges, optionally preserving pitch with rubberband when available in the build.

Exported files are re-encoded locally; extreme factors degrade clarity. Processing time is short relative to video because only audio samples are manipulated.

Load audio, set speed factor between roughly 0.5× and 2×, enable pitch preservation if you want speech to sound normal, and export. Listen to a short section before sharing long files.

For transcription, 1.25×–1.5× often remains intelligible with pitch correction on.

Slowing music below 0.75× may sound warbled without advanced algorithms.