ConvertCove

Video converter

Convert phone and screen recordings to MP4 or WebM, make a GIF from a clip, or pull the soundtrack out as MP3, without uploading a single frame.

or drop files here · processed on your device, never uploaded

    Popular video conversions

    Supported conversions

    FromTo
    MP4 MP3, GIF, WEBM, MP4
    MOV MP4, WEBM, GIF, MP3
    WEBM MP4, GIF, MP3, WEBM
    MKV MP4, WEBM, GIF, MP3
    AVI MP4, WEBM, GIF, MP3

    What this video converter does

    Open MP4, MOV (including iPhone footage), WebM, MKV or AVI files. Choose MP4 (H.264 + AAC) when the video has to play everywhere, WebM (VP8 + Vorbis) for open web use, GIF for a short silent loop, or MP3 to keep only the audio.

    In the options you can scale the video down to 1080p, 720p, 480p or 360p (it is never upscaled), pick a quality level, remove the audio track, and trim to a start and end time. For GIFs you choose the width and frame rate, which are the two settings that decide how big the file gets.

    Speed and size limits, honestly

    Everything runs in a single browser thread, so video encoding is slower than a desktop app: expect a one-minute 1080p clip to take one to three minutes on a recent laptop, and longer on phones. Lowering the resolution to 720p roughly halves the time. Extracting MP3 audio is fast because no video is encoded.

    Files up to 2 GB are accepted, and you will see a warning above 500 MB. The input is read directly from disk, but the converted output is held in memory until you download it, so very long high-resolution videos can exhaust the memory of a phone or tablet. Trim first if you only need part of a recording.

    Privacy

    Video is the kind of file people least want to upload: family clips, screen recordings with private data, unreleased work. ConvertCove processes it with FFmpeg compiled to WebAssembly inside your tab. The engine is downloaded once; your footage stays on your device.

    Read how in-browser conversion works.

    Frequently asked questions

    Why is my MOV from an iPhone so much smaller as MP4?

    It usually is not: iPhones record HEVC, which is very efficient. Converting to H.264 MP4 at the same resolution often makes the file larger. Choose 1080p or 720p and Balanced quality to keep the size reasonable.

    Can I convert MKV with subtitles?

    The video and the first audio track are converted. Subtitle tracks are not carried into MP4, WebM or GIF output.

    Is there a watermark or time limit?

    No watermark, no sign-up and no clip-length limit. The only limits are your device’s memory and patience.

    Does it use my GPU?

    No. Browsers do not give WebAssembly access to hardware video encoders, so all encoding runs on the CPU. That is the price of keeping the file on your device.