Convert AC3 to WebM

You choose it, because audio alone has no picture. The default is a static waveform render, and you can supply a still image instead — cover art, a title card, a photo — which is held for the whole duration. That is what makes the file uploadable to video-only platforms that will not accept a bare audio track. AC-3 is Dolby Digital, the surround format standardised for laserdisc, DVD, ATSC broadcast and cinema in the early 1990s. WebM plays natively in every modern browser with no plugin, no licence fee and no patent exposure, which makes it the default for web-embedded video.

Only if it has to be. Where the WebM container accepts the source audio codec directly, the stream is copied in untouched and stays bit-identical. Where it does not, the audio is transcoded once to whatever WebM does accept, at a bitrate matched to the source so the second pass costs as little as possible. AC-3 is lossy multichannel audio, normally 5.1 at 384 or 448 kbps, with metadata for dialogue normalisation and downmixing. WebM is deliberately narrow: VP8 or VP9 video (AV1 more recently) with Vorbis or Opus audio, and nothing else.

Barely larger, if you use the default still image. A single held frame compresses to almost nothing across the whole duration because every frame is identical to the last, so the file is dominated by the audio track. Choosing an animated waveform instead adds real video data and can double or triple the result.

Yes, and the AC3 would not have. Browsers ship a decoder for WebM and none for AC3, so an AC3 link forces a download while a WebM renders inline. That is usually the deciding factor when the file is going onto a web page rather than into an application.

Yes — WebM carries multichannel audio properly, so a 5.1 mix stays 5.1 with the channel layout intact rather than being folded to stereo. That matters if the file is destined for a home cinema receiver rather than a phone, which will downmix at playback time anyway.

Yes — basic AC3 → WebM conversion is free with no registration. Premium adds higher per-file size limits, more parallel batch workers, and removes ads.

Free accounts: up to 100 MB per AC3 file. Premium: typically 1 GB per file, depending on the AC3 source type. Very large files are split into chunks server-side when the WebM format allows.

Conversion preserves all information that both AC3 and WebM can represent. Format-specific features that the WebM format doesn't support (e.g. vector data in raster output, formulas in plain-text output) are rasterized or stripped — see the format-specific notes on the result page.

Yes — drop multiple AC3 files into the upload zone and they are queued in parallel. Premium has more parallel workers; on a 50-file batch this is the difference between minutes and seconds.

Yes — the UI is responsive and the conversion pipeline runs server-side, so mobile devices upload-then-download just like desktops. iOS and Android browser file pickers (camera roll, Files app) work end-to-end.

Chrome, Firefox, Safari (15+), Edge, and Opera. The converter uses standard `<input type="file">` upload — no WebAssembly or PWA dependencies — so even older browsers work.