Convert Video
Convert videos between popular formats — Flexible • Private • Fast
Import your video files
Before you process: Re-encoding may reduce picture or audio quality. Subtitles, chapters and metadata may not be preserved in the output.
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Help & tips
How to convert a video
- Select one or more videos and choose an output format (MP4, WebM, MKV, MOV or AVI).
- Choose Low, Medium or High video quality; Medium is selected initially. Higher quality may produce much larger files.
- Keep "Copy compatible streams when possible" enabled to avoid re-encoding where possible. Choose a resolution and whether to keep audio.
- Start conversion, then play and check each output before downloading or deleting the original.
Example use cases
- Use WebM for a browser-friendly VP8/VP9 video, or MP4 for broad playback compatibility.
- Choose High to prioritize visual detail, or Low for smaller files when some loss of detail is acceptable.
Limitations to consider
- For WebM re-encoding, FileMorning prefers browser VP9 through WebCodecs and falls back to FFmpeg.wasm when VP9, decoding or required features are unavailable. Browser support varies.
- Medium and High may generate files larger than the original. Re-encoding cannot restore detail already lost in the source.
- Very large or long videos can exceed device memory limits. Do not close the tab during conversion.
- Extra tracks, subtitles, chapters and metadata may not be preserved. Verify the output.
Questions and practical tips
Which quality should I use?
Low prioritizes speed and a smaller file, but visible detail loss is possible. Medium balances speed and picture quality (default). High prioritizes visual detail, often at the cost of a much larger file. Compare a sample before a long conversion.
What does "Copy compatible streams" do?
When the input video/audio codecs can be stored in the chosen container and you keep the original resolution, the streams can be copied without re-encoding. This is fast and preserves the original encoded quality. Otherwise the selected quality is used for re-encoding.
Why are some WebM conversions faster?
For WebM output, FileMorning first copies already-compatible streams without re-encoding when possible. When re-encoding is required, it prefers VP9 through WebCodecs, with Low, Medium or High quality selected by you. If VP9 is unavailable or fails, FFmpeg.wasm takes over. VP8 is not used for automatic WebCodecs re-encoding because a tested browser VP8 encoder caused periodic keyframe artifacts. Speed varies by video, browser and device.
Does the selected video leave my device?
This version processes video locally in your browser and does not upload the selected file for conversion. The Mediabunny processing library currently loads on demand from a third-party CDN if it is not already cached; an Internet connection can therefore be needed the first time.
Why can a long video take a long time?
Converting without stream copy decodes and re-encodes many frames. A tiny video file can still contain thousands of frames; conversion speed is device- and browser-dependent.
Processing and file safety
This tool processes files in your browser. Loading the page, libraries or AI models can still require network connections. Keep a copy of your original files and check the downloaded result before deleting them. Large files may require more memory and processing time than your device can provide.