Convert MOV to MP4 or MP4 to MOV without re-encoding
Lossless in-browser container remuxing. The picture and sound are copied byte-for-byte with zero quality loss and zero watermark.
Select a MOV or MP4 video
Select a file to inspect stream codecs and remux to another container.
Related Video Tools
About this video container converter
Select a MOV or MP4 video file, choose your target container format (MP4 or MOV), and click Convert. The video and audio bitstreams are remuxed into the destination container format without re-encoding, finishing in seconds with zero loss in visual quality and no watermark.
Online video converters typically upload your entire video file to remote cloud servers and run it through a heavy FFmpeg transcode. That process takes minutes, burns upload bandwidth, degrades image resolution, and often slaps a watermark on your footage. This tool performs container remuxing directly in your browser. It copies the raw H.264/H.265 and AAC elementary streams into a new container header, preserving every bit of original fidelity.
Step by step
- 1Load MOV or MP4 fileSelect your video file. The demuxer reads the file type atom (ftyp) and movie atom (moov) to verify internal track codecs.
- 2Select destination containerChoose MP4 for universal compatibility across web browsers, Windows, and Android, or MOV where a QuickTime-native container is wanted.
- 3Verify codec compatibilityThe engine confirms that the internal codecs (such as H.264 video and AAC audio) are supported by the target container without transcoding.
- 4Export remuxed videoClick Convert to assemble the new container. The output file is generated in milliseconds and ready for instant download.
Container remuxing vs lossy re-encoding
A video file consists of a container format (like .mov or .mp4) wrapping elementary compressed streams (like H.264 video and AAC audio). In many cases, an iPhone or camera records standard H.264 video inside an Apple QuickTime .mov container. To make this file play on Windows or Android, you do not need to compress the video again — you only need to repackage the packets into an ISO Base Media .mp4 container. This process, known as remuxing, operates at disk copy speeds and avoids generational quality degradation.
Honest limits and unsupported codecs
Remuxing only succeeds when the elementary streams inside are supported by the destination container specification. Professional QuickTime MOV files containing Apple ProRes video or uncompressed Linear PCM audio cannot be carried inside standard MP4 containers without re-encoding. If this tool encounters ProRes, PCM audio, or unsupported codecs, it immediately refuses the operation and explains the exact technical limitation rather than producing an unplayable file.
File size and bitrate preservation
Because the video and audio frames are copied byte-for-byte, the output file size will be virtually identical to the input file (differing only by a few kilobytes of container header metadata). Users expecting a video converter to dramatically compress file size should note that file size reduction requires re-encoding with lower bitrates, whereas this tool is engineered specifically for lossless format interchange.
Zero upload security guarantee
Every response from this site is served with a Content Security Policy whose connect-src directive is set to none. That is not a promise in marketing copy; it is an instruction to your browser, and the browser is the one enforcing it. While this page is open it cannot open a connection to anywhere — not to this site, not to anyone else — so there is no path by which your document could be uploaded, not by a bug, not by a future change, not by a script that should not be here. e2e/egress-proof.spec.ts asserts the served header and then tries to send data out by every route a page has and requires each attempt to be refused, and it runs on every build.
The second half of the guarantee is that the code has nowhere to send anything from. lib/tools/local-source-policy.test.ts reads every source file under lib/tools, workers, components and app on every test run and fails the build if any of them contains fetch, XMLHttpRequest, WebSocket, EventSource, sendBeacon or a peer connection, or even a remote address written down in a comment. A tool here cannot acquire an upload by accident, because the file that would have to contain one cannot be committed.
Client-side processing limits
Computations run directly on your own device using WebAssembly, Web Workers, and modern browser APIs including Web Crypto and TextDecoder. There are no server queues, no background telemetry, and no temporary cloud files created. Large operations remain responsive by offloading heavy parsing and conversion tasks to dedicated worker threads, ensuring the browser UI never freezes during intensive document and data processing tasks.
Questions people ask
- Will converting MOV to MP4 reduce video quality?
- No. The video and audio packets are transferred directly into the MP4 container without re-encoding or compression, ensuring bit-for-bit identical picture quality.
- Why did the conversion fail on my MOV file?
- If your MOV file was recorded with Apple ProRes video or uncompressed PCM audio, it cannot be packaged into a standard MP4 file without a lossy transcoding pass. The tool reports incompatible codecs by name.
- How fast is the conversion process?
- Because frames are copied rather than re-encoded, multi-gigabyte files convert in seconds rather than minutes, running at local disk copy speeds.
- Does this tool add watermarks or limits?
- Never. All tools on this site operate with zero watermarks, zero subscriptions, and zero artificial limits using zero-copy streaming file slices.
- Are my video files uploaded to your servers?
- No. All operations run locally inside your browser under strict connect-src none security policies, with zero data leaving your machine.