MP4 to WEBA Converter

How to Convert MP4 to WEBA Online

1. Upload Your MP4 Files: Drag and drop one or more MP4 or M4V videos, or click "Add Files." Conversion runs on our servers — no account, no watermark, batch supported.
2. Pick a Quality Preset: Default is "Very High (Recommended)." Choose Highest for music masters, High for podcasts, Medium for voice, or Low/Very Low/Lowest for speech-only memos where small file size matters more than fidelity. Each preset maps to an Opus target bitrate (roughly 24 kbps at Lowest up to ~256 kbps at Highest).
3. Tune Audio Channel and Sample Rate (Optional): Set Audio Channel to Original, Mono, or Stereo. Mono cuts file size roughly in half for voice content. Sample Rate options are Original, 8000, 12000, 16000, 24000, 44100, or 48000 Hz — Opus internally resamples to 48 kHz, so 48000 is the native choice. Optional File Compression, Specific File Size, Custom Bitrate and Constant Bitrate sections give fine control if you need to hit a target size.
4. Trim and Convert: Set a start time and duration in seconds or HH:MM:SS.sss to extract a segment, then click Convert. Each track is decoded from the MP4 (almost always AAC), re-encoded as Opus, and written to a .weba file you download immediately.

Why Convert MP4 to WEBA?

WEBA is the community shorthand for an audio-only WebM container — the official MIME type registered with web browsers is audio/webm, and the .weba extension simply signals "no video track inside" to file managers and players. The audio stream is almost always Opus, the IETF-standardized royalty-free codec that powers YouTube's audio-only streams, Discord voice, Google Meet, and WhatsApp voice notes. Pulling audio out of an MP4 and into WEBA gives you a dramatically smaller file (a 10-minute MP4 podcast at 256 kbps AAC drops from ~30 MB to ~5 MB at 64 kbps Opus with no audible loss) while keeping the file natively playable in every modern browser.

• HTML5 audio embedding — Drop the WEBA into an <audio> element with type="audio/webm". Chrome 33+, Firefox 15+, Edge 14+, and Safari 18.4+ play Opus-in-WebM natively. For older Safari, pair with an MP3 fallback <source>.
• YouTube-style audio archival — YouTube's audio-only DASH stream uses Opus in WebM. Converting your source MP4 to WEBA produces a file in the same encoder family the platform uses internally.
• Voice and podcast publishing — Opus at 32-48 kbps mono sounds comparable to MP3 at 96-128 kbps, so a one-hour interview drops from ~50 MB MP3 to ~14 MB WEBA without a perceptual hit.
• Discord and Matrix voice clips — Both clients accept WEBA uploads and play them inline because the underlying decoder is the same Opus stack they use for live voice.
• Web-app voice memos — JavaScript's MediaRecorder API outputs audio/webm;codecs=opus natively in Chrome and Edge. Converting MP4 source recordings to WEBA keeps everything in the same codec, so the browser plays them back without a transcoding step.
• Storage compaction — When archiving large MP4 lecture recordings where the visuals are slides you've already saved separately, dropping the H.264 video track and keeping only Opus audio cuts file size by 80-95%.

MP4 vs WEBA — Format Comparison

Opus Bitrate Quick Guide

Source bitrate guidance is from the Opus codec design paper and matches Xiph.org's published recommendations.

Frequently Asked Questions

What exactly is a.weba file, and is it different from.webm?

.weba and .webm use the same underlying WebM container. The convention is that .weba files contain only an audio track (typically Opus, sometimes Vorbis), while .webm files contain video and usually audio. The IANA-registered MIME type is audio/webm for both — the .weba extension is a community/operating-system convention rather than a separate standard. If a player refuses to open a .weba file, renaming it to .webm almost always works.

Will converting MP4 (AAC) to WEBA (Opus) hurt audio quality?

It's a lossy-to-lossy transcode, so there is some second-generation degradation, but Opus is efficient enough that the loss is inaudible at sensible bitrates. AAC at 128 kbps re-encoded to Opus at 96 kbps is generally indistinguishable from the source in blind listening tests. If you have a lossless source (FLAC, ALAC) you'll get a cleaner result by encoding to Opus directly rather than going AAC → Opus.

Can I play WEBA files on iPhone and iPad?

Safari on iOS gained full Opus-in-WebM playback support starting with iOS 18.4 (released April 2025). On older iOS versions, Opus playback was partial — the codec decoded but the WebM container wasn't fully supported in the audio element. For broad iOS compatibility across older devices, convert MP4 to MP3 or MP4 to AAC/M4A instead. Android Chrome and most Android media players have played WEBA natively for years.

Why is WEBA so much smaller than the original MP4?

You're discarding the video track entirely (often 90%+ of MP4 file size) and re-encoding the audio with a codec that's roughly 2× more efficient than AAC at low bitrates. A 100 MB MP4 with H.264 video and 192 kbps AAC audio typically drops to 5-15 MB as WEBA depending on the chosen Opus bitrate.

What sample rate should I pick for the output?

Opus internally operates at 48 kHz regardless of input — it's the only sample rate the codec natively encodes. If you select 8000, 12000, 16000, or 24000 Hz, Opus narrows its band but still writes 48 kHz to the file metadata. For MP4 sources captured at 44.1 kHz (typical music) or 48 kHz (typical video), pick "Original" or 48000 Hz for the cleanest path.

Does this work for MP4 files that contain multiple audio tracks?

The converter extracts the default (first) audio track, which matches how most players behave. MP4 containers with multiple language tracks or a separate commentary track will give you only the primary track in the output WEBA. If you need a non-default track, demux the MP4 with FFmpeg first to isolate the track you want.

Can I convert MP4 to WEBA in Vorbis instead of Opus?

This converter targets Opus, which is the modern WebM audio codec and the one virtually all current browsers and players support best. Vorbis-in-WebM is an older combination (still valid per the WebM spec) but is rarely chosen today — Opus encodes more efficiently at every bitrate Vorbis supports and adds low-latency modes Vorbis lacks. If you specifically need Vorbis, use MP4 to OGG which targets the Ogg container with Vorbis audio.

How do I trim out a specific section of audio while converting?

Use the Trim controls to set Start and Duration. Both accept seconds (e.g., 90) or HH:MM:SS.sss (e.g., 00:01:30.000). Only the selected window is decoded and re-encoded — useful for grabbing a single quote from a long interview or extracting an intro jingle. If you need finer cut-and-merge control, the audio cutter tool offers timeline-based editing.

Will WEBA files work in audio editors like Audacity or Adobe Audition?

Audacity 3.2+ imports WebM/Opus directly via FFmpeg. Adobe Audition does not natively read .weba — convert to a more interchange-friendly format first (WEBA to MP3 or WEBA to WAV) for round-tripping into pro audio software.