Is this video speed changer free and watermark-free?

Yes. Changing video speed in CutCull is free in your browser and never adds a watermark.

What happens to the audio when I speed up or slow down a video?

By default, CutCull scales audio tempo while preserving natural pitch so voices do not sound high-pitched or distorted. You can also mute any clip to export without an audio track.

Can I change the speed of only part of a video?

Yes. Mark one or more In/Out subclips and set a custom 0.1×–10× speed on each range, or use the full-clip row to change the entire video without cutting.

Does changing video speed upload my file to a server?

No. All decoding and encoding happen on your device inside this browser tab. Your original video remains untouched.

Change video speed online — free, no upload

Speed up or slow down MP4 and MOV videos from 0.1× to 10× right in your browser. Change the speed of the whole file or individual subclips with pitch-preserved audio or one-click mute — your footage never leaves this device.

Open the free editor

Free
No watermark
Nothing is uploaded
No install

HOW IT WORKS

Three steps, start to finish.

01
Select your video
Bring up to 20 local MP4 or MOV files per session. CutCull keeps read-only references; nothing is uploaded.
02
Pick a speed from 0.1× to 10×
Use the full-clip row to change the whole video at once, or mark In/Out subclips and set a different speed, reverse, or mute on each range.
03
Render and download
Preview the speed change in real time, then render a new MP4 file with pitch-corrected audio (or muted) and download it.

WHAT IT DOES

What you get

Continuous 0.1× to 10× control

Create smooth 0.25× or 0.5× slow-motion replays or 2×, 4×, and 10× hyperlapse clips in 0.01× steps.

Pitch-preserved audio or mute

Audio automatically stays in sync at natural pitch across speed changes, or click the speaker icon to export a silent MP4.

Whole video or per-clip speeds

Adjust the entire recording from the default full-clip row, or split one video into multiple clips with independent speeds.

Combine with grade, LUT, or crop

Pair speed changes with 14 color sliders, built-in Looks, .cube LUTs, and aspect-ratio crops in a single render pass.

Verified local MP4 output

Every sped-up or slowed-down clip is rendered locally with WebAssembly and checked for duration, frame count, and playability.

WHY NOTHING IS UPLOADED

Speed changes without uploading your footage

Previewing and re-encoding run locally in your browser with WebAssembly. CutCull never receives your videos, file names, or speed settings.

HONEST LIMITS

What the WebApp can and cannot do

Sessions hold up to 20 files, each under about 2 GB. Speed changes re-encode the video; HDR sources with speed or reverse export as standard SDR in the browser. Desktop Chrome or Edge is recommended.

QUESTIONS

Answers before you start.

Is this video speed changer free and watermark-free?: Yes. Changing video speed in CutCull is free in your browser and never adds a watermark.
What happens to the audio when I speed up or slow down a video?: By default, CutCull scales audio tempo while preserving natural pitch so voices do not sound high-pitched or distorted. You can also mute any clip to export without an audio track.
Can I change the speed of only part of a video?: Yes. Mark one or more In/Out subclips and set a custom 0.1×–10× speed on each range, or use the full-clip row to change the entire video without cutting.
Does changing video speed upload my file to a server?: No. All decoding and encoding happen on your device inside this browser tab. Your original video remains untouched.

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