Tachyon Audio
Time Stretch

Tachyon Audio Time Stretch is a desktop application for Windows and Mac OS that does only one thing: time stretching audio files.

Tachyon Audio Time Stretch is designed to achieve the best possible quality at any price.

What is Time Stretching?

Time stretching consists in changing the speed of a sound or music, without affecting the frequency and pitch.

Original file [1]
Time-stretched using
Tachyon Audio Time Stretch:
30% faster
30% slower
Note: Playing any audio excerpt will
stop the previous one if not finished.

Tachyon Audio Time Stretch is designed for the highest possible quality. A fast CPU is required, and only off-line processing is possible.


Buy Tachyon Audio Time Stretch

KVR Audio

Download the demo version

Version 2.0.0:

Windows (64-bit)
Mac OS

Limitations of the demo version

The demo version has the following limitations:

Apart from that it is equivalent to the full version.

Download an unofficial version
Not officially supported - use at your own risks
Linux (generic)
Windows (32-bit)
Generic (Java)
System requirements

Listen to audio examples
A natural sound...

In each column below, one sample is the original one, and the others are time stretched using Tachyon Audio Time Stretch. Can you tell which one is the original one in each column?

Sample 1 [2] Sample 2 [3] Sample 3 [4]
Note: Playing any audio excerpt will
stop the previous one if not finished.

A lot of efforts have been put to mitigate the traditional artifacts of audio time stretching: hashed or granular sound, boxy / metallic timbre, warbling, smearing, "thin" sounding, etc.

Tachyon Audio Time Stretch is designed to always sound natural, never "processed".

Optimised for quality...

Time stretching is a difficult DSP problem. Any time stretching algorithm is a compromise between processing speed and quality.

The following table compares two music excerpts time stretched using:

Drums [5] Pop / Voice [6] Note: Playing any audio excerpt will
stop the previous one if not finished.
Time-stretched at 160% of the length by: Processing speed
Approximate, on a 3 GHz processor
WSOLA > 100x
(> 100 times faster than real-time)
Based on SoundTouch.
> 10x Based on Gradient time stretch.
< 0.1x At maximum (and default) quality 4
~ 3x At minimum quality 1

As you can see, Tachyon Audio Time Stretch is optimised for the best possible quality, not for processing speed.

High fidelity...

High fidelity means "close to the original".

Each of the following samples alternates between an untransformed music and the same music transformed with Tachyon Audio Time Stretch.

Sample 1 (New Age [7]) Sample 2 (Pop / Rock [8]) Sample 3 (Classical [9])


The musics have first been transformed using Tachyon using a fixed ratio, and then a DAW has been used to slice and join pieces from both the original and the transformed versions. Tachyon itself does not support changing the time stretching ratio in the middle of a song.

Samples 1 and 3 alternate between original and half speed. Sample 2 alternates between original and 1.6 times slower.

And more...

This page contains other audio examples time stretched by Tachyon and by 3 other time stretching algorithms.

This YouTube channel contains entire musics time stretched at half tempo (50% of speed / 200% of length) by Tachyon:

Due to YouTube re-encoding the audio, quality might be slightly lower than what Tachyon Audio Time Stretch actually produces, especially in under 720p resolutions.


Click on an image to zoom it in and out.

Main window
Output settings dialog
Advanced transform settings dialog
Mini Player
Global settings: processing
Global settings: appearance
Audio output file information dialog
Main window + advanced settings dialog, in one of the dark themes
More information

Read the Online Documentation.

Read the FAQ (Frequently Asked Questions) part of the online documentation.

Musical references

[1] Melanie G 'MySweetDarkness', "The Morn", Through the Shadow and the Light, Everlasting Dream, 2007
[2] Rémy Gazel, "Betilla the Fairy", Rayman 1 soundtracks, Ubisoft, 1995
[3] John Lennon, "Imagine", Imagine (2010 - Remaster), EMI Records LTD, 2010
[4] Olof Gustafsson, "Hover Chase", Pinball Illusions soundtracks, Digital Illusions, 1995
[5] Musical Youth, "Schoolgirl", The Youth of Today, MCA, 1982
[6] Sia, "Bird Set Free", This Is Acting, RCA Records, 2016
[7] David Arkenstone, "Trail of Tears", Return of the Guardians, Narada Productions, 1996
[8] Daniel Powter, "Bad Day", Daniel Powter, Warner Records Inc., 2005
[9] Jean Michel Jarre, "Oxygène 13", Symphonic Jean Michel Jarre Disc 2, Silva America, 2006

Tachyon Audio Time Stretch logo
Enjoy music
at any speed

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