MP4 to WebM Converter

Drag & Drop or Click to Select a MP4 Video

MP4 in, WebM out

Tip: paste a video file from clipboard (Ctrl/⌘+V).

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Settings are written to the URL as you change them. Nothing differs from the defaults yet.

Convert an MP4 to WebM for embedding on a website. The picture is re-encoded to VP9 and the sound to Opus, unless the MP4 already holds those codecs.

WebM for web pages

A <video> element can play WebM with VP9 in every current browser. VP9 needs about 30% fewer bits than H.264 for the same picture, so a background video or product clip costs the page less to load. Keep the MP4 as a fallback source for older Safari versions.

Copied and re-encoded streams

H.264 or HEVC video: re-encoded to VP9 at the source size.
VP9 or AV1 video: copied unchanged.
AAC or MP3 audio: re-encoded to Opus.
Opus or Vorbis audio: copied unchanged.

The Plan section shows which applies to the loaded file before you convert.

Encoding time

Browsers often encode VP9 in software, so a WebM export usually takes longer than an MP4 one of the same clip. Frame size and frame rate are unchanged; to shrink the file further, use the Video Compressor, which can scale the frame down and target a size.

Frequently Asked Questions

Why convert MP4 to WebM?

For video on a web page. VP9 in WebM plays in every current browser, uses an open codec, and is usually smaller than H.264 at the same quality, so the page loads less.

Is the video re-encoded?

H.264 and HEVC video is re-encoded to VP9, because WebM cannot hold them. If the MP4 already holds VP9 or AV1, as some downloaded videos do, the stream is copied without re-encoding.

Why is this slower than converting to MP4?

Browsers often encode VP9 in software on the processor, even on machines that have a hardware H.264 encoder, so the same clip takes longer to export as WebM than as MP4.

What happens to the audio?

AAC and MP3 audio is re-encoded to Opus, the audio codec WebM uses. Opus at the default rate is transparent for most listeners.

Jump straight to a conversion

Full Video Converter tool

001 MKV to MP4 Converter

002 MOV to MP4 Converter

003 WebM to MP4 Converter

Explore Our Tools

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Video Converter

Convert video between MP4, MOV, WebM, and MKV. Streams that already fit the new container are copied without re-encoding; the rest are re-encoded to H.264, VP9, AAC, or Opus.

Black and White Video Converter

Convert a color video to black and white using perceptual luminance, with optional auto-contrast, partial desaturation, and inversion. Exports MP4 or WebM with the original soundtrack.

Remove Audio from Video

Remove the soundtrack from a video and keep the picture exactly as it is: the video stream is copied without re-encoding, into the same format. Works with MP4, MOV, WebM, and MKV.

Note to Frequency Converter

Convert a note name to its frequency in hertz, or a frequency to the nearest note with its offset in cents. Set the A4 reference between 390 and 500 Hz, and read the MIDI number, the period, and the wavelength alongside it.

Extract Audio from Video

Pull the audio track out of an MP4, MOV, MKV, WebM, or MPEG-TS file. Copy it into a new container without re-encoding, or decode it to WAV, MP3, M4A, Ogg Opus, or FLAC.

Color Grading Video

Grade a video with separate colors for the shadows, midtones, and highlights, and shift the crossover between them. Luminance stays close to the original. Exports MP4 or WebM with the original soundtrack.

Droste Video Effect

Nest smaller, rotated copies of every video frame inside itself for an infinite-tunnel Droste effect. Set recursion depth, scale per level, and rotation per level. Exports MP4 or WebM with the original soundtrack.

Film Stock Video Emulator

Grade a video to one of seventeen named film stocks, including Portra 400, Kodachrome 64, Velvia 50, CineStill 800T, and Tri-X 400, with grain that moves on every frame and trims for exposure, contrast, grain, and halation. Exports MP4 or WebM with the original soundtrack.