offlinewebtools.com browser-local workbench

Video Speed Changer

Adjust video playback speed to create fast-forward or slow-motion effects with synchronized audio speed adjustment.

Shipped

Browser local

Source file *

Files are processed locally in your browser using WebAssembly. This input is required.

Saved FFmpeg presets (stored locally)

Saved presets

Preset name

Preview and export

Inspect the source before running FFmpeg, then preview the generated output before downloading.

Local media

Choose a media file to fill this source preview before processing.

Expected output

The generated file preview, size, type, and download action appear here after processing.

Speed Multiplier

0.5 = half speed, 1.0 = normal, 2.0 = double speed

What this tool does

Video Speed Changer helps you adjust video playback speed to create fast-forward or slow-motion effects with synchronized audio speed adjustment.

What you get

Video Speed Changer produces a direct output in this page and keeps all processing on your device, with nothing uploaded to our servers.

If this tool misbehaves, share a quick summary so we can investigate. We include the tool URL automatically—no need to copy and paste.