ConvertFast

Online Video Converter

Convert videos between popular formats, adjust resolution, or extract audio.

This converter is temporarily unavailable because a required system dependency is missing on the server.

Drop your file here

or click to browse — max 500 MB

Files are automatically deleted after 30 minutes.

What is a video converter?

A video converter changes a video file into another container or encoding so it plays on your device, uploads cleanly, or matches an editing workflow.

Supported video formats

MP4, WEBM, MOV and MKV are available when FFmpeg is installed. You can also extract an audio track to MP3 or M4A without leaving this page.

How to convert a video

  1. Upload a video file.
  2. Choose the output format, resolution and quality.
  3. Keep, remove, or extract audio.
  4. Convert and download. Files expire after 30 minutes.

MP4 vs WEBM

MP4 is broadly compatible across phones, desktops and social platforms. WEBM is common on the web and can be efficient with VP9, but support varies by device. Choose MP4 for maximum compatibility and WEBM when your destination prefers it.

Video resolution and quality

Lower resolutions and “Smaller file” settings reduce size and processing time. Higher quality keeps more detail but takes longer and may create larger downloads. Start with Balanced unless you have a specific delivery target.

Why video files become larger or smaller

File size depends on codec, bitrate, resolution and duration. Re-encoding a highly compressed source at a higher quality setting can increase size. Downscaling or choosing a smaller-file preset usually reduces it.

Need to convert only audio?

Use Extract audio above, or open the dedicated Audio Converter. For images, visit the Image Converter.

Frequently Asked Questions

What is a video converter?

A video converter changes a video file into another container or codec, for example MOV to MP4 or MP4 to WEBM, so it plays where you need it.

Which video formats can I convert?

MP4, WEBM, MOV and MKV are available when FFmpeg is installed. You can also extract audio to MP3 or M4A.

Why did my file get larger?

Re-encoding with a higher quality setting, less compression, or a less efficient codec can increase file size even at the same resolution.

Can I change resolution?

Yes. Keep the original resolution or select 480p, 720p or 1080p before converting.

Need only the soundtrack?

Use Extract audio in the video tool, or open the Audio Converter for audio-only files.