What happens between defined speed segments?

Every uncovered source range automatically plays at 1x, so only the blocks you create are slowed down or accelerated.

Can speed ranges overlap?

No. Dragging and numeric edits are constrained to non-overlapping intervals, preventing conflicting rates at one source time.

Does 0.25x slow motion generate intermediate frames?

No. Existing frames are retimed; there is no optical-flow or AI interpolation, so very slow sections may look less fluid.

How is audio handled across changing speeds?

When retained, audio follows the same range map so section boundaries and overall synchronization match the video.

Back to Video Tools

Change Video Speed

Map independent 0.25x–4x speeds onto multiple source ranges while every unmarked part continues at normal speed.

Add a video

Apply different playback speeds to multiple source sections.

Choose video

MP4, MOV, WebM, MKV or AVI · or drag and drop

Your video is processed locally and never uploaded.

How to use Change Video Speed

1
Choose a video and click Add speed segment for each interval that should differ from normal playback.
2
Move or resize timeline blocks, or enter exact Start time and End time values; segments cannot overlap.
3
Assign each selected block a preset or custom speed from 0.25x to 4x and decide whether to Keep original audio.
4
Preview the changing rate, compare original and calculated duration, then export and download the MP4.

Frequently asked questions

About Change Video Speed

Change Video Speed uses a source-time map instead of one global rate. Independent blocks can highlight an action slowly, skip routine footage quickly and leave surrounding context untouched at 1x.

The player adopts each block's rate as the playhead crosses it, while the duration estimate recalculates the result. Export applies the same timing structure to retained audio without inventing interpolated frames.