Speed up or slow down a video from 0.25× to 4×, adjust its audio tempo and export a new MP4.
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No registration · Free to useHow to use Video Speed Changer
- Choose files and inspect preview and input limits.
- Choose a multiplier: 0.5× slows down and 2× speeds up.
- Generate, inspect the actual output and download; keep the source file.
Frequently asked questions
How do I speed up or slow down a video?
Choose a speed from 0.25× to 4×. The source player immediately previews that rate. Generate MP4 when satisfied; the result plays at normal 1× because the speed change is already encoded in the file.
How do video speed changes affect duration and audio pitch?
Output duration is approximately source duration divided by speed. A 60-second clip at 2× becomes about 30 seconds. Sound changes tempo with the picture while approximately retaining pitch; silent video stays silent.
Does slow motion automatically create new frames?
It does not create newly captured action or use AI frame interpolation. Low-frame-rate footage can look less smooth when slowed, and extreme rates can introduce audible processing artifacts.
Does changing player speed change the downloaded file?
A player’s own speed menu changes playback only. This tool’s speed selector controls preview and export; generate and download the new file to keep the effect.
What if sound seems out of sync after changing speed?
Picture and original sound are adjusted together. Check the generated result rather than the source. Existing source synchronization problems or corruption are not automatically repaired.
What size and duration limits apply to Video Speed Changer?
Video input is limited to 100 MB, 10 minutes and a 1920 × 1080 frame pixel budget, also applied to portrait frames. Output is limited to 150 MB; trim a shorter source interval if the output is too large.
Does Video Speed Changer require registration?
No account is required and the tool is currently free. Download results before closing or refreshing the page. Initial loading needs an internet connection; processing speed depends on the device and file size.