- How do I convert a video to MP4?
- Upload your video, select MP4 as the output format, choose your preferred quality, and click Process. The conversion runs entirely in your browser using FFmpeg WebAssembly — nothing is uploaded to a server.
- What video formats and codecs are supported?
- Input supports virtually any format the browser can read, including MP4, MKV, MOV, AVI, WebM, and OGG. Output formats include MP4 (H.264), MKV, MOV, AVI, and OGG. Common codecs like H.264, H.265, VP8, and VP9 are handled automatically.
- Can I convert a video without losing quality?
- Use the High quality preset to preserve as much detail as possible. For lossless container changes (e.g. MKV to MP4 with the same codec), the tool re-encodes at a high bitrate to minimize quality loss.
- Is there a file size limit?
- Browser processing comfortably handles files up to about 2 GB — your device's memory is the practical limit. On a paid plan, bigger files process on our servers instead: up to 20 GB on Pro and 50 GB on Business.
- Why won't my MKV file play on my phone?
- Most phones play MP4 reliably but support MKV only through a third-party player, even when the video inside is ordinary H.264. Converting the file to MP4 fixes playback without changing what you see.
- What is the difference between a container and a codec?
- The container is the wrapper - MP4, MKV, MOV - and decides how streams, subtitles and metadata sit in the file. The codec is the compression inside, such as H.264 or H.265. Two MP4 files can hold completely different codecs.