Press record. Get an MP3.
safe · secure · no server · works offline · fast
…or paste a file you copied in Finder, or just start typing at the cursor.
↓ scroll for about & FAQsafe · secure · no server · works offline · fast
…or paste a file you copied in Finder, or just start typing at the cursor.
↓ scroll for about & FAQThe tab opens as a single control, because the answer to “record something” should be one control. Everything a recording actually depends on sits behind a small Advanced disclosure: which microphone, which quality, what the recording is called, and what the file is called.
What is not hidden is the size. Every preset states what it costs per hour and what a full two hours would weigh — about 55 MB at the Voice preset, about 275 MB at Studio — and once you are running, that number counts up beside the clock. Constant‑bitrate MP3 is exactly that arithmetic, so there is no reason to make anyone guess.
A browser cannot record MP3. MediaRecorder writes
WebM/Opus nearly everywhere and MP4/AAC on
Safari, which is why most browser recorders hand you a .webm
and leave the rest to you. OmniViewer does the last step here: when you
stop, the capture is transcoded by a real ffmpeg compiled to
WebAssembly, with libmp3lame doing the encoding. The
core is about 31 MB and is fetched once, the first time you ever stop a
recording — never on page load. Nothing is uploaded to do it.
The finished MP3 hands straight off to the MP3 converter for WAV, FLAC, M4A, Opus or Ogg, or to MP3 STUDIO to have a shorter clip cut out of it losslessly — whole frames copied, nothing re‑encoded. The hand‑off never touches your disk: the file already in memory is passed straight into the toolkit that reads it. To bend it instead, the TRANSFORM tab has twenty effects.
It’s one lens on OmniViewer’s Voice Recorder — Record MP3 Online: drop a file and every tab is one click away. OmniViewer opens every file format, entirely in your browser — no upload, no server.
No. OmniViewer is a static page with no server-side processing. The microphone is opened by your browser, the audio is captured and encoded to MP3 on your own machine, and nothing is sent anywhere — there is no server to send it to. The microphone is released the moment you stop recording or leave the page.
Two hours in a single take. The limit is enforced rather than merely documented: the recorder stops itself at 2:00:00 and says so, rather than silently truncating. At the Voice preset that is about 55 MB, and at Studio about 275 MB — both shown before you start.
A real MP3. Browsers cannot record MP3 natively — they record WebM/Opus, or MP4/AAC on Safari — so OmniViewer transcodes the capture in the page with a genuine ffmpeg compiled to WebAssembly, using libmp3lame. The encoder is about 31 MB and is downloaded once, the first time you stop a recording, never on page load.
Voice (64 kbps mono) for speech, interviews and memos — it is small enough to email a two-hour recording. Standard (128 kbps mono) is the default and is transparent for a voice. High (192 kbps stereo) if you want the room or an instrument. Studio (320 kbps) is the most MP3 can carry and is worth it only if the source deserves it.
Almost certainly echo cancellation, noise suppression or auto gain control — three pieces of DSP browsers apply to a microphone by default. They are tuned for video calls, so they remove room sound, treat non-speech as noise to be suppressed, and continuously adjust your level. All three can be turned off under Advanced, and the CAPABILITIES tab shows whether the microphone actually honoured the request.
Yes — the TRANSFORM tab has twenty, rendered offline over the finished recording so they are exact and undoable. Helium and Demon shift pitch while keeping the duration, which a browser cannot do on its own. There is synthesised reverb, echo, robot, telephone, megaphone, underwater, vinyl, whisper, alien, reverse, chipmunk and slow-mo, plus street, rain, café and stadium backgrounds that are generated rather than sampled.
Yes. The finished MP3 hands straight off to OmniViewer’s /mp3 EXPORT tab, which converts it to WAV, FLAC, M4A, Opus or Ogg — from the file already in memory, so it is never written to disk or uploaded on the way. /mp3 STUDIO will also cut a shorter clip out of it losslessly, without re-encoding a single frame.
Yes, on any modern mobile browser that supports MediaRecorder — which is all of them. Safari records into MP4/AAC rather than WebM/Opus and OmniViewer transcodes either one to MP3 the same way. The interface is one large button by design, which is as true on a phone as on a laptop.