Free Online Video & Audio Converter

Convert media files between formats without uploading them. Pick a file, choose the output format, and the conversion runs in your browser — free, with no monthly limit.

How it works

  1. Upload your file. Drag and drop a video or audio file into DomeScribe, or click the upload area to browse your device. The file stays on your device — conversion runs in your browser.
  2. Choose your output format. Pick the format you want: MP4, MOV, AVI, WebM, MKV, or FLV for video; MP3, WAV, FLAC, AAC, OGG, or M4A for audio in the audio converter.
  3. Optionally change resolution or frame rate. For video, you can downscale to 1080p, 720p, 480p, or 360p and set 60, 30, or 24 fps. Leave both on "Original" and DomeScribe copies the streams into the new container without re-encoding, which is fast and lossless.
  4. Convert and save. Click Convert. The first run loads the ~31 MB in-browser engine (cached afterwards); then the file is converted on your device and you can save the result with a free account.

Converter at a glance

Video formats
MP4, MOV, AVI, WebM, MKV, FLV — optional resolution (4K to 360p) and frame rate (60/30/24 fps)
Audio formats
MP3, WAV, FLAC, AAC, OGG, M4A
Privacy
Runs 100% in your browser (WebAssembly) — your file is never uploaded to a server
Speed
No upload wait — processing starts as soon as the in-browser engine loads (~31 MB, cached after the first run)
File size
Limited by your device's memory — up to about 500 MB works reliably
Watermark
None
Limits
Free — no monthly limit; runs on your device (a free account is needed to save the file)

Frequently asked questions

What formats does the DomeScribe media converter support?

Video: MP4, MOV, AVI, WebM, MKV, and FLV. Audio (in the audio converter): MP3, WAV, FLAC, AAC, OGG, and M4A. Pulling the audio out of a video is handled by the audio extractor, which outputs MP3 free and M4A, FLAC, WAV, and more on paid plans.

Will I lose quality when converting?

If you leave resolution and frame rate on "Original", DomeScribe copies the video and audio streams into the new container without re-encoding — no quality change at all. If you change either setting, or convert to WebM, the video is re-encoded as H.264 at a quality-based setting (CRF 23) that most viewers cannot distinguish from the source.

Is there a file size limit for conversion?

There is no server limit because nothing is uploaded. Large files are limited by your device's memory — up to about 500 MB works reliably; bigger files may fail to load on phones or low-memory laptops.

Can I convert multiple files at once?

DomeScribe converts one file at a time. There is no monthly limit, so you can queue up the next file as soon as the current one finishes.

Is the media converter free to use?

Yes — free, with no monthly limit, because the conversion runs on your own device rather than on a server. A free account is needed to save the converted file.

Can I convert video to MP3 with DomeScribe?

Yes. Use the audio extractor: upload the video file, keep MP3 selected, and click Extract. The MP3 is encoded on your device at the encoder's highest variable-bitrate setting.

What is the best free video converter that does not upload your files?

DomeScribe converts video and audio entirely in your browser using WebAssembly — your file never leaves your device. That makes it private (nothing to upload to a server) and means there is no upload or download wait. It handles MP4, MOV, AVI, WebM, MKV, and FLV video plus MP3, WAV, FLAC, AAC, OGG, and M4A audio, free.

Is it safe to convert videos online?

With most online converters your file is uploaded to someone's server, which is a real privacy concern for personal or confidential footage. DomeScribe avoids that entirely: conversion runs inside your browser and the file never leaves your device — you can watch the network tab and see that nothing is uploaded.

Does DomeScribe add a watermark to converted files?

No. Converted files are clean — no watermark, no branding, no trial stamp. The output is your original content in the new format.

Related tools

  • Convert MP4 to MP3 Online — Convert MP4 video to MP3 audio free, in your browser. Pull the audio track out of an MP4 file on your device and save it as MP3 — nothing is uploaded.
  • Convert MOV to MP4 Online — Convert MOV files to MP4 free, in your browser. Turn an Apple QuickTime video into a universally compatible MP4 — nothing is uploaded, no installation.
  • Convert WAV to MP3 Online — Convert WAV files to MP3 free, in your browser. Shrink a WAV roughly 7–8x while keeping great audio quality — nothing is uploaded, no monthly limit.
  • Convert Video to Audio Online — Convert a video file to audio free, in your browser. Extract the audio track as MP3 (FLAC, WAV, M4A on paid plans) — nothing is uploaded, no monthly limit.
  • Extract Audio from Video — Extract the audio from a video file on your device as MP3 — free, no monthly limit. Runs in your browser, nothing is uploaded. FLAC, WAV, M4A on paid plans.
  • Compress Video Online — Compress video files in your browser — typically 50–80% smaller with little visible quality loss. Free, no monthly limit, the video never leaves your device.