Free Audio Speed Changer — Slow Down or Speed Up Any Part of a Song
Quick answer: To change the speed of a song, load the file, drag the speed slider (0.50×–2.00×) for the whole track — or press Split to give each section its own speed — then choose whether the pitch follows the speed or stays put, press Start Processing and download.
An audio speed changer makes a song or recording play faster or slower. This one also splits a file into up to eight sections, so each part can have its own speed and pitch — the whole song, or just the chorus, in one browser tab with no upload.
Speed and pitch are separate properties, so this tool lets you set both. Speed alone changes how long the track lasts; the pitch setting decides whether the voice rises and falls with it (tape style, which is what sped-up and slowed edits use) or stays exactly where it was (time-stretched, which is what practice and speech need). Sections are joined with 12 ms equal-power crossfades, and reverb, tone and limiting run once at the end so a fast section cannot clip.
Free forever: Speed AND pitch control · Only the section you pick changes · Nothing is uploaded.
How to Speed Up or Slow Down a Song
- Drop the song: MP3, WAV, M4A, OGG or FLAC. The file is decoded on your device and never leaves it.
- Set the speed — for everything, or one part: Drag the speed slider for the whole track, or press Split and give each section its own speed. Drag a blue handle to move where the tempo changes.
- Choose what the pitch does: Pitch follows speed for sped-up / slowed character, or pitch kept so the key stays the same. The extra pitch slider transposes a section on its own.
- Process and download: Press Start Processing, watch the 0–100% bar, then press Download. You get WAV or MP3 up to 320 kbps, free.
What this audio speed changer tool does
- Whole Song or One Section: One slider for the entire track, or split into up to 8 sections and set a different speed for each — 1.00× sections stay exactly as they were.
- Speed and Pitch, Separately: Pitch follows speed (tape), pitch kept (WSOLA), or an extra semitone shift on top. The page prints the exact pitch each section will come out at.
- Drag the Boundary, Not the Numbers: Move the handle to the second the tempo should change; both neighbouring sections reflow instantly, so the timeline can never have a gap.
- Equal-Power Crossfades: Every join is blended over 12 ms, so a tempo change sounds like a transition instead of a click.
- Loop, BPM Match & Exact Length: Loop one section until you nail it, detect the file's BPM and re-time to a target tempo, or fit a section to an exact length for a video cut.
- WAV + MP3 up to 320 kbps, Free: No watermark, no signup, no daily limit — export lossless WAV or MP3 at 320/192/128 kbps.
Speed & Pitch Cheat Sheet
| Goal | Setting | Why |
|---|---|---|
| Classic sped-up edit (TikTok) | 1.15×–1.25×, pitch follows speed | The pitch rising with the tempo is what makes a sped-up edit sound sped-up. |
| Nightcore | 1.30×, pitch follows speed | Faster and roughly +4 semitones — the classic nightcore colour. |
| Slowed, natural-sounding | 0.85×–0.90×, pitch kept | Tempo drops while the vocals stay in key, so nothing sounds detuned. |
| Daycore (slowed + deeper) | 0.9×, pitch kept, extra pitch −2 to −3 | The extra slider lowers the key on its own, on top of the slowdown. |
| Practise a hard passage | Section 0.70×, pitch kept, loop on | Tempo drops, the key stays the same, and the loop repeats just that bar. |
| Match a target tempo | Detect BPM → target BPM (pitch kept) | A tempo match that shifts the key is not a tempo match, so the page switches to pitch-kept for you. |
| Section must hit an exact time | Type the seconds and press Fit to that length | The speed is solved from the source length, so the section lands on your cut. |
| Smoother joins | Make each section at least 4–5 seconds | Longer sections leave plenty of material for a clean crossfade. |
What Actually Happens to the Sound
Speed and pitch are independent properties of audio, even though turntables and tape machines tie them together. Play a record faster and the pitch rises with the tempo, because both come from the same rotation — that coupling is what gave sped-up and slowed edits their character. Time-stretching separates them: the WSOLA algorithm used here (the same one behind the Sped Up and Slowed pages) moves duration while holding the fundamental frequency, so a solo at 0.70× is still in the same key you have to play.
This page supports both, plus a manual transpose. When a section has both a speed change and a pitch shift, two stages run: a cubic resample performs the transposition (it moves pitch and duration together), then a WSOLA pass restores the duration the speed setting asks for while holding the pitch the resample produced. That is why a section can be slower AND deeper (daycore), or faster AND brighter — and it is why the page prints the resulting pitch in semitones instead of leaving you to guess.
Sections are then written into one output timeline, joined with 12 ms equal-power crossfades: the incoming part fades in on a sine curve while the outgoing one fades out on a cosine curve, so the summed level stays constant rather than dipping. Reverb, tone and limiting are applied once, at the end, because limiting each section separately would make a loud drop quieter than the intro. The limiter holds the export at −0.3 dBFS, which is the headroom MP3 encoding needs to avoid inter-sample clipping.
Who Uses an Audio Speed Changer
- Editors & Remixers: Keep the verse as it is, push the drop to 1.20×, then let the outro settle back to 1.00× — one export, no timeline.
- Musicians Practising: Slow one solo to 0.70× with the pitch kept and loop it, leaving the rest of the backing track at full speed.
- Podcast Editors: Speed up a slow answer without pitching the intro, the theme music or the outro.
- Students & Transcribers: Slow down a dense passage and keep the rest at normal speed, so the file stays the length it should be.
- Voice & Character Work: Transpose a take up or down a few semitones on its own, or make a deeper “daycore” style version of a track.
- Shorts & Reels Creators: Drop the tempo for the hook and snap it back for the cut — the change lands exactly where you put the handle.
Audio Forge Pro vs Other Speed Changers
Most free speed changers apply one ratio to the whole file, and keep their best settings behind an account.
| Feature | Audio Forge Pro | Desktop app | Cloud tools |
|---|---|---|---|
| Change a section only | ✅ Up to 8 sections | ✅ But manual cutting | ❌ Whole file only |
| Speed and pitch independent | ✅ Per section | ⚠️ Plugin maths | ⚠️ Usually one or the other |
| Crossfade at every join | ✅ 12 ms equal power | ⚠️ You set it up | ❌ None |
| Output quality | ✅ WAV + MP3 320 kbps | ✅ Lossless | ⚠️ Often 128 kbps free tier |
| Upload required | ❌ Never leaves your device | ❌ Installed app | ✅ Upload required |
| Limits | ✅ No signup, no daily cap | 💸 Paid licence | ⚠️ Runs per day / account |
All Audio Forge Pro Tools
- AI Silence Remover — Remove dead air automatically
- -14 LUFS Normalizer — YouTube & Spotify loudness standard
- Stereo to Mono Fixer — Fix single-ear left audio & downmix
- Audio to Video — Waveform audiogram for Shorts & clips
- Extract Audio from Video — MP4 to MP3 — no upload, local encode
- Audio Joiner — Merge MP3 files on a timeline
- Audio Trimmer — Cut MP3 — split, delete, reorder
- Auto Ducking — Voice over music — music ducks when you speak
- Remove BG Music — AI voice/music split — free, unlimited
- Add Echo to Audio — Slapback, tape, ping-pong & karaoke echo presets
- Add Reverb to Audio — 10 convolution spaces — room to cathedral
- Slowed and Reverb — Slowed edits with hall reverb & warm bass
- Sped Up Song Maker — 1.15x TikTok speed, or keep the pitch
- Nightcore Maker — 1.3x speed + pitch — the classic sound
- 8D Audio Maker — Rotating pan + room — headphones on
- Audio Speed Changer — Whole song or one section — speed and pitch
- Voice Echo Effect — Speech-tuned echo and plate for vocals
- Full Audio Studio — All tools in one workspace
Audio Speed Changer — Frequently Asked Questions
How do I change the speed of a song online?
Open this page, drop the song and drag the speed slider — below 1.00× slows it down, above 1.00× speeds it up. Press Start Processing, then Download. You can also split the song into sections and give each section its own speed instead of one speed for the whole track.
Is this audio speed changer free and unlimited?
Yes. There is no signup, no watermark, no daily run limit and no premium tier — the decoding, speed change, pitch shift and encoding all run in your browser on your own device.
Does speeding a song up make the voice sound higher?
Only if you want it to. With pitch follows speed the voice rises with the tempo (1.25× is about +3.9 semitones) — that is the sped-up and nightcore sound. With pitch kept the tempo changes while the voice stays in the same key, which is what practice, transcription and most podcasts need.
Can I slow a song down AND make it deeper?
Yes. Set the section to pitch kept, then use the extra pitch shift and pull it down 2–3 semitones. The page shows the resulting pitch before you process, so you can hear the difference between a natural slowdown and a darker, daycore-style one.
Can I speed up just one part of a song?
Yes. Split the file into sections, set a speed such as 1.20× on the section you want faster, and leave the other sections at 1.00×. The export is one continuous file where only that section changed.
How many sections can I make?
Up to 8 sections per file, each with its own speed and pitch. The default split is 2, 3 or 4 equal sections, which you then drag to where the tempo should actually change.
Will there be a click or a gap where the speed changes?
No. Every join is a 12 ms equal-power crossfade, so the audio blends over the boundary. If a section is too short for a fade, the page warns you and uses a 4 ms ramp instead of risking a click.
Can I change speed without changing pitch?
Yes — choose Keep original pitch for that section. It uses time-stretching, so the tempo changes and the key stays the same: a guitar part at 0.70× is still in the key you have to play in.
How long will the finished file be?
The page adds up the sections before you process: each section's output length is its source length divided by its speed, minus the small crossfade overlap. The summary above the buttons shows the exact result, taken from the same plan the renderer uses.
Can I loop one section while I practise?
Yes. Select the section and turn on Loop until I stop it — that section's original audio repeats until you press Stop, and the loop follows whichever section you select.
Can I set a target BPM or an exact length instead of a speed?
Yes. The tempo tools measure the file's BPM and then apply whatever speed turns it into the BPM you type. You can also type a length in seconds for the selected section, and the page solves the exact speed that makes that section come out that long.
Does it work on long files and on mobile?
Yes, on desktop and mobile browsers, with no artificial length cap. Speed changes are real CPU work on your device, so a long file takes longer on a phone than on a laptop, and very large pitch shifts add processing time.
Can I use this on music I do not own?
The tool processes whatever you load, but publishing a modified version of a recording you do not own is a licensing matter. Use music you own or have permission to publish for anything you post.
Which audio files can I load into the speed changer, and does it run on a phone?
WhatsApp voice notes (.opus, .ogg), Voice Memos and recorder output (.m4a, .caf, .3gp), MP3, WAV, FLAC, and the audio track of MP4, MOV or WebM clips. Everything decodes in your browser, so the picker on your phone opens your normal file list — and the section handles are press-and-slide, so the whole editor works with one thumb.
Sped Up Song Maker | Slowed and Reverb | Nightcore Maker | Trim a Section First | Add Reverb | All free audio tools