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Video Speed Controller
Online Free

Speed up or slow down any video — from 0.25x ultra slow motion to 4x fast forward. Live preview, browser-based, nothing uploaded.

100% Free
No Upload Required
0.25x to 4x Speed
Live Preview

Drop your video here

or click to browse — MP4, MOV, AVI, WebM, MKV and more
MP4MOVAVI WebMMKVWMV+More
—
Duration: — Resolution: — Size: —
Choose Speed
Custom 1.0x
Speed: 1.0×
Original: —
New duration: —
Normal speed
Live Preview Preview plays at selected speed in real time
1.0×
0:00 0:00
Output Options
Processing video… 0%

✓ Speed Applied!

Speed: — Duration: — File size: — Format: —
Download Video

How It Works

Change your video speed in three simple steps.

1

Upload Your Video

Drag and drop or click to select any video file. MP4, MOV, AVI, WebM, MKV and more are all supported.

2

Choose a Speed

Pick a preset — 0.25×, 0.5×, 2×, 4× — or drag the custom slider to any speed between 0.25× and 4×. The preview updates instantly.

3

Download Instantly

Click Apply Speed — FFmpeg processes your video in the browser. Download immediately with no waiting, no uploading.

Everything You Need

A complete video speed controller that runs in your browser.

0.25× to 4× Speed Range

From ultra slow motion at 0.25× to 4× fast forward. Use presets or the custom slider for any speed in between.

Live Preview at Exact Speed

The preview video plays at the exact speed you select — no guessing. See the result before exporting.

Pitch-Corrected Audio

Audio is re-pitched to match the new speed — voices and music stay natural instead of chipmunk or distorted.

Duration Preview

See exactly how long your output will be before processing. A 10-minute video at 2× becomes 5 minutes.

100% Private

All processing runs in your browser with FFmpeg WebAssembly. Your video never leaves your device at any point.

All Formats Supported

Accepts MP4, MOV, AVI, WebM, MKV, FLV and more. Export as MP4, WebM, or MOV.

Why Change Video Speed?

Speed Up — Save Time

Removing dead time from recordings, lectures, or screen captures makes content more engaging and watchable.

  • Speed up long lectures or webinars
  • Create time-lapse effects from regular footage
  • Compress long screen recordings
  • Make content fit a shorter time slot

Slow Down — Add Detail

Slowing down footage reveals detail invisible at normal speed — essential for sports, tutorials, and analysis.

  • Analyze sports technique frame by frame
  • Create dramatic slow motion effects
  • Show detail in how-to tutorial videos
  • Highlight key moments in action footage

Frequently Asked Questions

What speed range is supported?
The tool supports speeds from 0.25× (quarter speed, ultra slow motion) up to 4× (four times fast forward). You can use the preset buttons for common values or the custom slider for any value in between.
Will audio pitch change when I speed up or slow down?
When "Keep Audio (pitch-corrected)" is selected, the audio is processed with FFmpeg's atempo filter which corrects the pitch so voices and music stay natural regardless of speed. You can also remove audio entirely if preferred.
Is my video uploaded to a server?
No. All processing happens entirely in your browser using FFmpeg WebAssembly. Your video file never leaves your device at any point.
How long will the output video be?
The new duration is shown in the summary before you export. At 2× speed a 10-minute video becomes 5 minutes. At 0.5× speed a 10-minute video becomes 20 minutes. The formula is: new duration = original duration ÷ speed multiplier.
Does it work on mobile?
Yes. The tool is fully responsive and works on Android and iOS using Chrome, Safari, or Firefox. No app download is required.
What formats can I export to?
You can export as MP4 (H.264 — recommended for maximum compatibility), WebM (VP8 — good for web), or MOV. The quality level can be set from high (CRF 18) to balanced (CRF 23) to smaller file (CRF 28).

Free Online Video Speed Controller — Change Speed in Your Browser

Our online video speed controller lets you change the playback speed of any video file — from 0.25× slow motion up to 4× fast forward — processed entirely in your browser using FFmpeg WebAssembly. No uploads, no server, complete privacy.

Speed Up vs Slow Down — Which Filter Does FFmpeg Use?

For video speed, FFmpeg's setpts filter is used — at 2× speed, the presentation timestamp of each frame is halved, making frames display twice as fast. For audio, the atempo filter adjusts tempo while preserving pitch, so voices and music remain natural at any speed. The two filters are applied together in a single pass.

Slow Motion Video — How It Works

True slow motion is typically created by recording at a high frame rate and playing back at a normal rate. Our tool achieves a similar effect by slowing down existing footage — at 0.25× each second of original footage becomes four seconds of output. While this is not the same as native high-frame-rate slow motion, it works well for analysis, tutorials, and creative effects on standard footage.

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