M4V to MP4 converter
Convert M4V videos to MP4 right in your browser — free, private and fully offline. Drop a M4V file, pick MP4, and choose a re-encode for maximum compatibility or a fast lossless remux. Nothing is uploaded and there is no file-size limit; the conversion runs entirely on your own device.
Open M4V to MP4 converter →Convert M4V to MP4 online — free and private
This M4V-to-MP4 converter runs entirely in your browser on the WebCodecs engine. Your video never leaves your computer — no upload, no account, no watermark and no file-size paywall — and it keeps working offline once loaded. Because M4V and MP4 files normally both carry H.264 and AAC, the Fastest mode can simply rewrite the container and copy the audio and video untouched — that finishes in seconds and loses nothing.
How to use M4V to MP4 converter
- Add your M4V video — Drag the M4V file onto the drop zone, or click to browse and pick it. The tool reads its container, resolution and codecs and shows them straight away.
- Choose MP4 — Pick MP4 as the output, then choose Best compatibility for a re-encode that plays everywhere, or Fastest to copy the existing tracks where the MP4 container allows it.
- Convert and download — Watch the progress, preview the result in the player, and save the .mp4 file.
Frequently asked questions
Is my M4V video uploaded to a server?
No. The conversion runs inside your browser using your own device's hardware, so the video never leaves your computer. There is no size limit and it works offline.
Will converting M4V to MP4 lose quality?
Not in Fastest mode — the existing video and audio are copied byte for byte and only the container changes, so the result is identical to the source. Best compatibility re-encodes, which does cost a little quality.
How long does it take?
A lossless remux takes seconds whatever the length. A re-encode runs about as fast as your computer's video hardware allows — a few minutes for a long clip is normal.
Which other formats can it convert?
The same tool reads MP4, M4V, MOV, MKV, WebM and MPEG-TS, and writes MP4, WebM, MKV and MOV. AVI, WMV and FLV cannot be opened — no browser can decode those containers.