FFmpeg.wasm · Video format converter

Free Online Video Format Converter

Browser-based video format converter that runs entirely in your browser using ffmpeg.wasm. Convert videos between MP4, WebM, MKV, MOV and AVI with options for scaling, FPS, CRF quality and audio bitrate, without uploading any files.

Select video file

Select a video file, load ffmpeg.wasm, then convert it between MP4/WebM/MKV/MOV/AVI locally in your browser. Adjust resolution, FPS, CRF and audio bitrate to balance compatibility, quality and file size.

Idle

Tip: codec support varies by browser and the ffmpeg.wasm build. MP4 and WebM are usually safest choices. Lower CRF values mean higher quality and larger files. All processing runs locally in your browser with no video uploads.

File & Output format

Output format Resolution FPS Quality (CRF) Preset Audio bitrate (kbps)

FFmpeg logs

Choose a video file, set the target format and parameters, then click “Convert”. If conversion fails for a specific format, try MP4 or WebM instead.

Subtitle Tools

Convert subtitle formats and fix timelines entirely in your browser, with UTF-8/GBK encoding support and no file uploads.

Video Compressor

Compress local videos to MP4 (H.264) with resolution, CRF and audio bitrate controls, all processed locally in your browser.

Video Player

Play local video files in your browser with speed, volume, loop and picture-in-picture controls, all processed locally with no uploads.

Video to GIF Converter

Convert local video segments to GIF with adjustable FPS and width, processed fully in the browser with no uploads.

Video Trimmer

Trim local videos by start and end time and export the selected part as a WebM clip, processed fully in the browser.

Scientific Calculator

Perform everyday calculations and basic scientific functions directly in your browser with keyboard support and no data uploads.