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GuideBest practicesBeginner

Change audio speed, add fades and reverse sound

Understand speed changes, fade-ins, fade-outs and audio reversal, with practical advice for editing and reusable browser workflows.

Published 30 August 2026Reading : 2 minBy Yann Bastien
Show contents
  1. Changing playback speed
  2. Fade-in and fade-out
  3. Reversing audio
  4. Order matters

Speed, fades and reversal are simple transformations, but their order can change the result significantly.

Changing playback speed

A speed change modifies the duration of the material. Depending on the processing method, it can also affect pitch. This is useful for previews, creative effects, language practice or adapting a clip to a target duration.

Always listen to speech after a large speed change: intelligibility can deteriorate before the numerical setting looks extreme.

Use the audio speed changer for this operation.

Fade-in and fade-out

A fade-in gradually raises the level at the beginning of a clip. A fade-out gradually reduces it near the end. Fades are useful for avoiding abrupt starts and stops, especially after trimming.

The audio fade tool can create these transitions locally in the browser.

Reversing audio

Reversal reads the samples in the opposite temporal order. It is mainly a creative operation, but it can also help inspect attacks, tails and sound-design material.

Use the audio reverser when you need a reversed copy without installing editing software.

Order matters

A fade-in followed by reversal becomes a fade-out on the reversed result. Likewise, trimming before a speed change is not equivalent to choosing timestamps after the duration has changed.

A clear pipeline makes this order explicit:

Import → Trim → Change speed → Reverse if needed → Fade → Export

You can build and reuse this sequence in the Bethemesh Workspace.

For a complete overview of the available operations, continue with Convert and edit audio files in the browser.

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