AnyTool
Your files never leave your device. All processing happens locally in your browser.

How do I slow down or speed up a video without the audio sounding like chipmunks?

Open AnyTool's Slow Motion / Speed Creator, drop in a clip, and drag the speed slider from 0.1x to 16x — the live preview plays at that speed with natural-pitch audio so you hear the real result instantly. When you download, a self-hosted ffmpeg engine renders an MP4 with correctly pitch-corrected audio. Everything runs in your browser — no upload, no watermark, no caps.

  • Slow motion or timelapse from 0.1x to 16x
  • Natural-pitch audio at any speed (no chipmunk effect)
  • Instant live preview before you render
  • 100% in your browser — no watermark, no upload, no caps

What is

Video speed change

Changing video speed retimes the footage (slow motion below 1x, timelapse above 1x). Pitch-preserving speed change keeps the audio at its original pitch using chained tempo filters rather than simply replaying it faster or slower. Client-side speed change renders the result in the browser without uploading the file.

Video Tools

Related terms

slow motiontimelapsepitch preservationplayback rateffmpeg

How to Change Video Speed

Create slow motion or timelapse in your browser.

30 secWeb browser
  1. 1

    Add a video

    Drop in a clip — it stays on your device.

  2. 2

    Set the speed

    Drag the speed slider (0.1x–16x) and preview the result live.

  3. 3

    Export

    Render and download the MP4 with natural-pitch audio — nothing is uploaded.

Result: A slow-motion or timelapse video

Frequently Asked Questions

No — audio stays at natural pitch at any speed.

Correct chained tempo filtering avoids the chipmunk/droning artifacts left by EZGIF, VidShift and similar tools.

No — speed changes run entirely in your browser with a self-hosted engine.

The clip never leaves your device and there is no watermark or 500 MB cap like Clideo, or 720p/10-min limit like VEED.

Yes — the live preview plays at the chosen speed with corrected pitch, no render needed.

You drag the slider and instantly see and hear the result; ffmpeg only runs when you download.

Detailed Explanation

Methodology

How the Slow Motion / Speed Creator Works

AnyTool changes video speed entirely in the browser. For an instant preview, it drives the HTML video element with playbackRate and preservesPitch=true so the chosen speed (0.1x–16x) is seen and heard immediately with natural-pitch audio — no encoding needed. On download, a self-hosted ffmpeg engine renders the result: video timing via setpts and pitch-preserved audio via a chained atempo filter (chained because atempo only accepts 0.5–2.0 per stage), output as H.264/AAC MP4 (or VP8/Vorbis WebM). A speed of 1.0x uses stream copy to remux losslessly.

  • Runs client-side — the clip is never uploaded
  • Self-hosted ffmpeg core — no CDN
  • Slow motion or timelapse, 0.1x to 16x
  • Natural-pitch audio via chained atempo (no chipmunk)
  • Instant playbackRate live preview before rendering
  • No backend, no watermark, no caps
Privacy & Security

Privacy vs Cloud Speed Changers

Clideo, EZGIF, online video editors and VEED upload your video and cap or watermark the free tier (Clideo 500 MB + logo, VEED 720p/10-min). AnyTool retimes locally; the clip never leaves the browser, the audio keeps natural pitch, and there is no watermark or size cap.

Video speed change: AnyTool vs typical tools
CapabilityAnyToolTypical tools
Data handlingIn your browserOften uploaded
Pitch-preserved audioYesOften chipmunked
Live previewInstant (no render)Rare
Watermark / capNoneCommon
CostFree, no signupFree/limited

AnyTool is a privacy-first client-side speed changer — retiming runs locally and nothing is uploaded.