DollarWise

Free MP4 to WebM Converter — Convert Video Online, No Sign-Up

October 16, 2026 · 2 min read · By the DollarWise team

WebM is the web’s favorite video format — smaller than MP4 at the same quality, and it plays natively in every modern browser. This free MP4 to WebM converter re-encodes your video with VP9 and Opus audio entirely in your browser. Nothing is uploaded, ever.

MP4 to WebM Converter

Convert MP4 videos to WebM (VP9 + Opus) — smaller files, same quality, free.

100% Free Forever No Sign-up No Credit Card Private — files never leave your browser Unlimited Use

1 Add your MP4 video

Drag & drop your MP4 hereor click to browse — the engine downloads once (~9 MB), then stays cached

    2 Settings

    Lower CRF = better quality, bigger file. 22 is the sweet spot for the web.
    Keep audio
    Re-encodes audio to Opus. Turn off for silent clips and even smaller files.

    3 Convert to WebM

    Working…

    ✅ Done — your WebM video

    🎉 Free forever. No sign-up. No credit card. No limits.

    Convert unlimited MP4s to WebM — VP9 encoding in your browser, no limits.

    How it works

    • Step 1 — Drop in an MP4. A video engine (ffmpeg.wasm) loads once in the background — about 9 MB, then cached.
    • Step 2 — Pick a quality preset or set the CRF yourself; choose whether to keep audio.
    • Step 3 — The video is re-encoded to VP9 + Opus WebM locally and downloads to your device.

    Everyday uses

    • Web developers — serve WebM for faster-loading <video> tags.
    • Bloggers — embed smaller videos that don’t eat bandwidth.
    • Discord & forums — WebM clips upload faster and play inline.
    • Archivists — keep an open-format copy of important clips.

    Note: re-encoding takes a while on long videos — short clips convert fastest.