Change Video Speed Online Free — No Upload

How to Change Video Speed

Upload your video

Drag and drop a video file or click to select it. Supports MP4, WebM, MOV, AVI, and MKV formats.

Choose a speed

Select from preset speeds: slow motion (0.25x, 0.5x, 0.75x) or fast playback (1.5x, 2x, 3x).

Download the result

Click apply and download the speed-adjusted video. Both video and audio are adjusted together.

Why use FyleTools to change video speed?

100% Private

Your video never leaves your device. All processing happens in your browser — no server uploads.

Free & Unlimited

No registration, no file limits, no watermarks. Change speed on as many videos as you need, completely free.

Smooth Audio at Any Speed

Audio pitch is preserved at all speeds using atempo filters, so the result sounds natural even at 3x speed.

Frequently Asked Questions

Is my video uploaded to a server?

No. All processing happens in your browser. Your video files never leave your device.

Is the audio pitch affected?

No. The tool uses atempo filters that maintain correct audio pitch regardless of speed, so voices and music sound natural.

What is the slowest speed available?

The slowest preset is 0.25x (quarter speed). You can achieve even slower playback by applying the tool multiple times.

What is the fastest speed available?

The fastest preset is 3x. Higher speeds are possible by applying the tool multiple times.

Does this work on my phone?

Yes. The tool runs entirely in your browser on any device, including smartphones and tablets.

What formats are supported?

MP4, WebM, MOV, AVI, and MKV as input. The output is MP4.

Can I create a slow-motion video?

Yes. Choose 0.25x or 0.5x to create a smooth slow-motion effect. For best results, start with a high frame rate source video.

Does changing speed reduce quality?

The video is re-encoded during speed changes. High-quality H.264 encoding is used to minimize any visible quality loss.

Can I speed up only a portion of the video?

To speed up a specific section, first trim that portion using the Trim tool, change its speed, then merge it back with the original using the Merge Videos tool.

Does slow motion increase the file size?

Yes. Slowing down a video increases its duration and therefore its file size. A 0.5x slowdown roughly doubles the file size.

Will the frame rate change?

The output frame rate matches the original. Slow motion distributes existing frames over a longer duration rather than creating new frames.

Can I remove the audio when changing speed?

To create a silent speed-adjusted video, use the Remove Audio tool first, then change the speed of the silent video.

When to Use This Tool

Create a dramatic slow-motion replay of a sports moment or action sequence at 0.25x or 0.5x speed.

Speed up a time-consuming tutorial or how-to video to 2x for viewers who want a quick overview.

Create a time-lapse effect from a long recording by speeding it up to 3x or applying multiple speed increases.

Slow down a fast-paced dance or exercise video to learn the moves at 0.75x speed.

Supported Formats

Format	Description	Best For
MP4 (input/output)	H.264 video	Universal speed-adjusted output
WebM (input)	VP8/VP9 web video	Web video speed changes
MOV (input)	Apple QuickTime video	iPhone recordings
AVI (input)	Legacy video container	Older video files
MKV (input)	Matroska container	High-quality source videos

Tips & Best Practices

For smooth slow motion at 0.25x, use source video recorded at 60 FPS or higher — low frame rate sources may look choppy.

Speed up long videos (2x-3x) for quick review, then trim the interesting sections at normal speed.

Preview a short section at the selected speed before processing the full video to ensure it looks right.

Combine speed change with the Trim tool to speed up only a specific section of the video.

How It Works — 100% Private Processing

FyleTools uses FFmpeg compiled to WebAssembly to adjust both video and audio speed simultaneously. The video uses the setpts filter to change frame timing, while the audio uses atempo for pitch-preserved speed changes. All processing happens entirely in your browser.