Convert videos between MP4, WebM, OGG, MOV, AVI, and MKV formats. Device presets for YouTube, Instagram, TikTok, iPhone, Android. Quality options from fast to high quality encoding.
Video file extensions are misleading. What most people call "an MP4" is actually a container (MP4) holding a video stream (typically H.264), an audio stream (typically AAC), and metadata. You can have an MP4 containing H.265 video and Opus audio, or an MKV containing H.264 video and AAC audio, the container and the codecs inside it are independent choices. Converting between video formats therefore means deciding three things: the container (MP4, MKV, WebM, MOV, AVI), the video codec (H.264, H.265, VP9, AV1), and the audio codec (AAC, Opus, MP3). The right combination depends on where the file is going. For broad compatibility, MP4 container with H.264 video and AAC audio is still the safest 2024 default, it plays natively in every browser, every phone, and on smart TVs. For web delivery where you control the playback environment, WebM with VP9 or AV1 is 30-50% smaller at equivalent quality. For pro editing workflows, MOV with ProRes preserves quality for further edits at the cost of file sizes 10-20x larger than H.264. MKV is the flexible choice for personal archives because it can hold multiple audio tracks, subtitle streams, and chapter markers that MP4 handles less gracefully.
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Convert video frame rate: 24fps (cinematic), 30fps (standard), 60fps (smooth gaming), 120fps (slow motion). Use-case presets for film, YouTube, gaming, and smooth motion interpolation.
Crop videos to any aspect ratio. Platform presets for Instagram (1:1, 9:16), YouTube (16:9), TikTok. Interactive crop area with rule of thirds grid. Real-time preview while cropping.
Trim and cut videos precisely with frame-by-frame scrubbing. Set start/end points visually, preview clips in real-time, and export trimmed videos instantly. No upload required - runs 100% in browser.
A client sent a .mov that will not play in the browser preview your stakeholders use.
Input
demo.mov (ProRes) → MP4 (H.264 + AAC)
Output
demo.mp4, universally playable, far smaller than ProRes
H.264 MP4 is the most broadly supported delivery format, so converting from a heavy editing codec makes the file both playable and lighter. Conversion is local, keeping unreleased footage private.
Video file extensions are misleading. What most people call "an MP4" is actually a container (MP4) holding a video stream (typically H.264), an audio stream (typically AAC), and metadata. You can have an MP4 containing H.265 video and Opus audio, or an MKV containing H.264 video and AAC audio, the container and the codecs inside it are independent choices. Converting between video formats therefore means deciding three things: the container (MP4, MKV, WebM, MOV, AVI), the video codec (H.264, H.265, VP9, AV1), and the audio codec (AAC, Opus, MP3). The right combination depends on where the file is going. For broad compatibility, MP4 container with H.264 video and AAC audio is still the safest 2024 default, it plays natively in every browser, every phone, and on smart TVs. For web delivery where you control the playback environment, WebM with VP9 or AV1 is 30-50% smaller at equivalent quality. For pro editing workflows, MOV with ProRes preserves quality for further edits at the cost of file sizes 10-20x larger than H.264. MKV is the flexible choice for personal archives because it can hold multiple audio tracks, subtitle streams, and chapter markers that MP4 handles less gracefully.
Convert videos that won't play on certain phones, TVs, or media players into universally supported MP4/H.264.
Use built-in presets to match exact format, resolution, and bitrate requirements for Instagram, TikTok, or YouTube.
Transcode bulky camera files (e.g., MOV from iPhones) into more compact formats for email or cloud storage.
Convert older AVI or WMV files into modern formats that work in current browsers and players.
Produce WebM files with VP9 for fast-loading, high-quality video on websites.
The converter runs FFmpeg compiled to WebAssembly, which means every codec and container combination supported by FFmpeg is available without leaving the browser. Transcoding is the technical term for what happens: the source stream is decoded to raw YUV frames, then re-encoded into the target codec. This is lossy for any lossy-to-lossy conversion because every encode-decode cycle discards some information that cannot be recovered. For quality-critical workflows, transcoding once is fine; transcoding the same file repeatedly through different formats (H.264 to H.265 to H.264 again) accumulates generation loss that becomes visible after a few cycles.
Platform presets are the practical way to avoid trial and error. YouTube recommends H.264 with specific bitrate targets per resolution (8 Mbps for 1080p30, 12 Mbps for 1080p60). Instagram feed wants 1080x1350 at 30 fps, 25 Mbps or less. TikTok accepts 1080x1920 at 30 fps, with a 287.6 MB total-file-size cap. The presets encode these requirements into a single click, so you can convert footage for Instagram, TikTok, and YouTube from the same source without re-reading spec documents for each. The alternative is specifying each parameter manually, which the custom mode supports when a platform preset does not quite match your needs.
Speed-quality tradeoffs in video encoding are governed by the "preset" parameter on the encoder, independent of output bitrate. H.264 with preset "ultrafast" encodes in roughly 1x realtime on a typical laptop CPU but produces files 20-30% larger than preset "medium" at the same CRF. Preset "slow" or "veryslow" takes 3-10x longer than "medium" and produces files 5-15% smaller. For web delivery of archived content where you encode once and serve many times, slower presets are worth the extra time. For one-off conversions for sharing, "medium" is the right tradeoff, and that is what the default presets use.
Any lossy-to-lossy conversion introduces some generation loss. Using higher quality settings minimizes this. For maximum quality, choose the highest quality preset and expect a larger output file.
MP4 with H.264 is the safest choice for broad compatibility. WebM with VP9 is ideal for web use. If you're targeting a specific platform, use the built-in preset instead.
Video transcoding is computationally intensive. Speed depends on your device's CPU, the input video's resolution, and the selected quality level. Lower quality settings encode faster.
This tool is designed for video. For audio-only conversions, use the dedicated audio format converter.
Video is decoded and re-encoded on your own device. Large files never leave your machine.