videocaptions.ai
Generate Captions
Video Converter

Convert video and audio without uploading

MP4, WebM, MOV, MKV, MP3, WAV and more, converted on your device. Nothing is sent to a server.

FreeNo uploadRuns in your browser

videocaptions.ai/Convert Video
Open Studio

Drop a video or audio file

Convert between MP4, WebM, MOV, MKV, MP3, WAV, and more. Everything runs in your browser.

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The same team builds videocaptions.ai. Add animated captions to a Reel, a Short or a TikTok in about a minute.

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About This Tool

How do I convert a video without uploading it?

This converter changes video and audio files between formats like MP4, WebM, MOV, MKV, MP3, and WAV entirely inside your browser. It uses your device's built-in WebCodecs engine, so the file never leaves your computer: nothing is uploaded to a server, there is no queue, and there is no file size cap imposed by an upload step.

Drop in a file, pick the output format and codec, and download the result. It is free, requires no signup, and adds no watermark. Because processing is local, a typical clip converts in seconds and your footage stays private.

How It Works

Three steps, no signup

  1. 01

    Drop your file

    Drag in any video or audio file. The tool probes the container, codecs, resolution, and tracks instantly.

  2. 02

    Pick the output format

    Choose MP4, WebM, MOV, MKV, MP3, WAV, and more. Codec options adapt to what your browser can encode.

  3. 03

    Convert and download

    Conversion runs on your device using WebCodecs. Download the result the moment it finishes.

FAQ

Quick answers

Yes. The converter is completely free with no watermark, no signup, and no daily limit. It is part of the free creator toolkit from VideoCaptions.AI.

No. Conversion happens entirely in your browser using the WebCodecs API. Your file never leaves your device, which also makes the tool safe for private or unreleased footage.

Video: MP4, WebM, MOV, and MKV. Audio: MP3, WAV, and more. You can also extract the audio track from a video, for example turning an MP4 into a WAV file.

There is no hard limit because nothing is uploaded. Very large files are constrained only by your device's memory, so multi-gigabyte files may be slow on low-end hardware.

Re-encoding always involves some compression, but you can choose the codec and quality settings. Passing through an unchanged track (for example keeping video and converting only audio) is lossless for that track.

Yes, it runs in any modern browser including mobile Chrome and Safari. Desktop browsers are faster for long videos.

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