Video

Change Video Speed

Speed a video up or slow it down, keeping the audio in sync.

Video file

Choose a file to convert. It's processed locally — never uploaded. Tip: add several files to convert them all at once.

Settings

Output

Result appears here after you select

{ } How it works

Change Video Speed works on the file you upload. Adjust the options, then select Process ▸ and it runs entirely in your browser — nothing is uploaded to a server — then shows the result in the Output panel.

Inputs

  • Video file — upload a file (video/*); it is read locally in your browser
  • Speed — choose one — 0.25× (very slow), 0.5× (slow motion), 1.5×, 2× (fast), 4× (default: 2× (fast))

Output

A downloadable MP4 file — use the Download button in the Output panel.

{ } Common uses

  • Make a slow-motion clip out of ordinary footage.
  • Speed up a long screen recording into a short demo.
  • Fit a clip into a platform’s time limit without cutting anything out.

{ } Limitations

  • Slowing footage down does not add detail — it shows each existing frame for longer, so very slow speeds look stepped unless the source was filmed at a high frame rate.
  • The audio is stretched in stages, because the filter that does it only handles halving or doubling at a time.

{ } FAQ

Is my data uploaded to a server?

No. Everything runs locally in your browser — your files never leave your device.

Can I process more than one file at once?

Yes — add several files and they’re all processed and downloaded together as a ZIP.

Is this tool free?

Yes — it’s completely free and needs no sign-up.

Does the audio still match the picture?

Yes. Both streams are re-timed together — the video timestamps are scaled and the audio is stretched by the same factor. Changing only one is what makes speed edits drift out of sync.