advanced station
Change Video Speed Online
Slow down or speed up a video and export an MP4 copy. Adjust playback speed from 0.25× to 8× using the shared speed control.
Active conversion station
Change Speed
Speed up or slow down video
How to speed up or slow down a video
Prepare the source
Select the video to retime.
Review the settings
Choose a multiplier from 0.25× to 8×.
Check the result
Start Conversion and check picture timing and sound in the output.
Supported formats and limitations
Input: MP4, AVI, MOV, MKV, WEBM. Output: MP4. Slow motion cannot create detail missing between source frames. The processor expects an audio stream, so silent inputs may fail. There is no variable speed ramp.
Processing runs on the server after you select Start Conversion. The interface accepts files up to 500 MB; service and connection limits can be lower. No installation or account is required. Read our file processing privacy policy.
For conversion, splitting, audio, and other file-based workflows, return to the Video Tools hub.
Why Use ConvertFast's Change Speed?
- Use one speed multiplier across the entire clip.
- Adjust audio timing alongside the video.
Frequently Asked Questions
What does 0.5× speed mean?
The video plays at half speed and lasts approximately twice as long. A 2× result plays twice as fast.
Can speed change gradually within the video?
No. One multiplier applies to the whole clip. Speed ramps require a video editor.
Ready? It's Free.
No account required. Input rules appear before you upload.
Open Change Speed Tool