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Free online tool
Audio Speed Changer
Free Online Song Speed Changer
Upload a song, slow it down or speed it up, preview the result, and export your edited audio as MP3 or WAV. No signup required. This audio speed changer runs in your browser.
Free online toolNo signupWorks in browserMP3, WAV, FLAC, OGG supportedPrivate browser-based processing
Upload Audio
Drag and drop your audio here, or click to browse. Supports MP3, WAV, FLAC, OGG, and M4A input files.
Speed range 0.25x to 4.00x in 0.01 steps
Presets from Super Slow Mo to Triple Speed
Preview, Download MP3, Download WAV
🎵 Want slowed + reverb instead? Use the main Slowed Reverb Generator.
Open Generator →How to Change Audio Speed Online
Choose the speed
Move the speed control below 1.00x to slow the song down or above 1.00x to speed it up.
Preview the result
Listen before exporting so you can check the timing, vocals, and overall feel.
Download your edited audio
Export your speed-changed track as MP3 or WAV.
Recommended Audio Speed Settings
| Use Case | Speed | Notes |
|---|---|---|
| Light slow down | 0.90x to 0.95x | Under a semitone of pitch drop, so it reads as a mood change rather than an edit. |
| Slowed + reverb | 0.80x to 0.88x | The band the whole genre settles on. Two to four semitones down — deep, still human. |
| Practice mode | 0.50x to 0.80x | Good for hearing fast passages, but the key moves too. Use 0.50x for an exact octave. |
| Podcast or speech | 1.10x to 1.50x | Speech stays intelligible well past where music stops sounding right. |
| Nightcore-style speed | 1.15x to 1.30x | Around three to four and a half semitones up. Pair with the nightcore maker for the full effect. |
Start with small speed changes first. Large changes can make vocals, drums, or instruments sound less natural.
Why Use This Online Audio Speed Changer?
Varispeed, and it says so
Speed and pitch move together here, like a record at the wrong RPM. That is stated up front because it decides whether this tool suits your job or works against it.
0.25x to 4.00x in 0.01 steps
A four-octave span at a resolution fine enough to match one track to another rather than only hitting round numbers.
The key change is documented
Every ratio moves the song by a specific interval. The table below gives it, so you know 0.85x is not just 'slower' — it is roughly a whole tone and a half down.
Nothing is invented
Varispeed re-reads the samples at a different rate. No windows, no crossfades, no interpolation guesswork — so there is no smearing on drums or consonants.
Adjust while it plays
The rate updates on the running audio, so finding the ratio that suits the track is a matter of listening rather than repeated exports.
The clock shows processed time
The running time next to the waveform is the length of the edit you are making, not the length of the file you uploaded — so a 0.75x slowdown reads as the longer track it actually is.
Every Speed Is Also a Key Change
This is a varispeed tool: it re-reads the samples at a different rate, exactly like playing a record at the wrong RPM. That has a consequence people often discover after exporting. Changing the rate scales every frequency in the file by the same factor, so the song does not merely get slower — it gets lower, by a specific and calculable interval.
The relationship is 12 × log₂(rate) semitones. Half speed is exactly one octave down; double speed is exactly one octave up. Everything in between lands somewhere less tidy, which is why the table below is worth a look before you pick a number.
| Speed | Pitch shift | Interval | What it suits |
|---|---|---|---|
| 0.25x | -24.0 st | Two octaves down | Extreme slowed edits; barely a song any more |
| 0.50x | -12.0 st | One octave down | Half speed — deep, but the key is intact |
| 0.75x | -5.0 st | A fourth down | Heavy slowdown; a real key change |
| 0.80x | -3.9 st | Roughly a major third down | Bottom of the slowed + reverb range |
| 0.85x | -2.8 st | Roughly a minor third down | The most common slowed edit setting |
| 0.88x | -2.2 st | Roughly a whole tone down | Top of the slowed + reverb range |
| 0.95x | -0.9 st | Just under a semitone | Subtle drag; most listeners will not name it |
| 1.25x | +3.9 st | Roughly a major third up | Nightcore territory |
| 1.50x | +7.0 st | A fifth up | Fast edits; also common for speech |
| 2.00x | +12.0 st | One octave up | Double speed |
Two things fall out of this table that are worth knowing.
The first is that the slowed + reverb band everyone converges on — roughly 0.80x to 0.88x — is not an arbitrary aesthetic choice. It corresponds to a drop of about two to four semitones, which is far enough to change the character of a voice noticeably but not so far that it stops sounding like a person singing. Slow past 0.75x and you cross into territory where the vocal reads as an effect.
The second matters if you are a musician slowing a track down to learn it: the slowed version is in the wrong key. At 0.75x you are practising a fourth below the record. If you are working out a part by ear and then playing along with the original, that is a genuine problem, and it is the one case where varispeed is the wrong tool rather than merely a trade-off. The workaround is to pick a rate that lands on a whole number of semitones — 0.50x is exactly an octave down, which is at least a key you can transpose back from in your head.
Which Tool You Actually Want
Because speed and pitch are locked together here, the right page depends on which of the two you are steering by.
Use this one when timing is the target — fitting audio to a video, speeding up a lecture, or dialling in a tempo by ear. Use the pitch shifter when the interval is the target and you would rather enter “down three semitones” than work out which ratio that is. Both run the same varispeed engine, so they will give identical audio for equivalent settings; the difference is which number you get to type. That page also covers the varispeed versus time-stretching trade-off in full, including where to find the tempo-preserving path on this site.
For a finished edit rather than a raw rate change, the slowed reverb generator pairs the slowdown with reverb, bass, and pitch in one pass, and the nightcore maker does the same going upward.
More Free Audio Tools
Slowed Reverb Generator
Slow songs and add reverb online.
Pitch Shifter
Raise or lower the pitch of a song.
Nightcore Maker
Make fast, high-pitched nightcore edits online.
Bass Booster
Increase low-end bass in songs and audio files.
Chopped & Screwed Maker
Slow it the Houston way — pitch drops with tempo, plus real beat-locked chops.
Reverse Audio
Change direction instead of tempo — play any song backwards and download it.
Complete Slowed Reverb Guide
Everything about slowed reverb: settings, workflow, presets, and tutorials.
Audio Speed Changer FAQ
Does changing audio speed change pitch?
In this tool, yes. It is a varispeed changer, so slowing the audio lowers the pitch and speeding it up raises it — the same coupling a record player has. The amount is 12 × log₂(rate) semitones: half speed is exactly an octave down, 0.85x is about 2.8 semitones down. The table above gives the figure for every common ratio.
Can I change speed without changing pitch?
Not on this page. Keeping the pitch fixed while the tempo moves requires time-stretching, which re-spaces overlapping windows of audio and can smear drums and consonants in the process. Varispeed avoids that entirely by not inventing anything, at the cost of taking the pitch along with it. The pitch shifter page explains the trade-off in full and points to where the tempo-preserving engine lives on this site.
What speed range does this tool support?
0.25x to 4.00x in 0.01 steps — four octaves end to end. The steps are fine enough to match one recording's tempo to another rather than only landing on round numbers.
What speed should I use for a slowed + reverb edit?
0.80x to 0.88x is where the genre has settled, and 0.85x is the single most common setting. That range drops the pitch by roughly two to four semitones, which is enough to change the character of a vocal without pushing it past sounding like a person. If you want the reverb, bass, and pitch controls alongside the slowdown rather than the raw rate change on its own, the slowed reverb generator does all of it in one pass.
I'm slowing a song down to learn it. Does the key change matter?
Yes, and it is the main thing to watch out for. At 0.75x you are hearing and practising a fourth below the record, so anything you work out by ear will be in the wrong key when you play along with the original. If you are learning a part rather than making an edit, use 0.50x — that is an exact octave down, so the note names are unchanged and only the register moves.
How fast can speech go before it stops being intelligible?
Speech tolerates far more than music does. The usual comfortable ceiling is somewhere around 1.5x to 2x depending on the speaker and how familiar you are with the material, and the limiting factor is normally the speaker's own pace rather than the tool. Music breaks down much earlier, because a mix has harmonic relationships to preserve and a voice has formants that give the shift away.