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Convert

Convert Video

Change a video's format so it plays where you need it. When the streams already fit the new container they are copied in seconds with no quality loss; otherwise they are re-encoded.

  • Nothing is uploaded
  • Free, no sign-up, no watermark
  • Works offline once loaded

Drop a video here

or choose a file

MP4, MOV, WEBM, MKV, AVI, M4V, 3GP, FLV, WMV and more

Processed on your device. Nothing is uploaded.

How to use Convert Video

  1. 1

    Add the video

    Drop a MOV, WebM, MKV, AVI or other video on the drop zone, or choose it from your device.

  2. 2

    Pick the output format

    Under Convert to choose MP4, WebM, MOV, MKV or AVI.

  3. 3

    Choose a method

    Fastest copies the streams when they already fit the new format, with no quality loss. Re-encode converts them for maximum compatibility and lets you set the Quality.

  4. 4

    Convert and download

    Press Convert, follow the progress, then Download the new file.

Why use Aback Video for this

  • Lossless remux

    When the video and audio codecs suit the new container, they are copied as they are. A MOV from an iPhone becomes an MP4 in seconds.

  • Compatible re-encode

    When the codecs do not fit, MP4 gets H.264 and AAC, WebM gets VP8 and Opus, AVI gets MPEG-4 and MP3.

  • Many inputs

    Opens MP4, MOV, WebM, MKV, AVI, M4V, 3GP, FLV, WMV, MPEG, TS, MTS and more.

  • Never uploaded

    The conversion runs in your browser. Your video stays on your device.

Frequently asked questions

Will converting reduce quality?

With Fastest, often not at all: if the streams can be copied, the new file contains exactly the same video and audio. If they must be re-encoded, the default high quality keeps the difference hard to notice.

Which format should I choose?

MP4 with H.264 plays on almost everything, so it is the safe choice. WebM suits websites. MOV suits Apple editing apps. MKV can hold many audio and subtitle tracks. AVI is for older software that requires it.

Why is my conversion slow?

It is being re-encoded, for example from HEVC to H.264 or into WebM. Re-encoding runs on one thread in the browser. Fastest finishes quickly whenever a copy is possible.

Is my video uploaded?

No. FFmpeg compiled to WebAssembly converts the file inside your browser tab.

Can it open every video?

Most common formats, yes. A few codecs are not included in this browser build, such as AV1 decoding and some professional camera formats. You will see a clear message if a file cannot be read.

Are subtitles and extra audio tracks kept?

The main video and audio tracks are converted. To keep subtitle tracks, extract them first with Extract Subtitles.

Does it work on phones?

Yes. Fastest is quick on phones; re-encoding long videos may take a while.

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