WEBA to AMR Converter

How to Convert WEBA to AMR Online

1. Upload Your WEBA File: Drag and drop or click "+ Add Files" to load one or more .weba clips. Batch is supported — every file uses the same conversion settings.
2. Pick AMR Quality Preset: Default is Highest, which targets AMR-NB at 12.2 kbit/s (toll-quality narrowband). Drop to Low for the 4.75 kbit/s mode if you need the smallest possible voicemail file. Set a Constant Bitrate manually if your downstream system expects a specific AMR mode (4.75, 5.15, 5.90, 6.70, 7.40, 7.95, 10.2, or 12.2 kbit/s for AMR-NB).
3. Adjust Audio Channel, Sample Rate, and Trim (Optional): AMR is mono only — leave Audio Channel at Mono. Sample Rate is locked to 8000 Hz for AMR-NB (16000 Hz for AMR-WB); the dropdown defaults to 8000 Hz. Use Trim to clip the WEBA before encoding so you're not paying a bitrate budget on silence.
4. Convert and Download: Click Convert. Files run on our servers, are encrypted in transit, and are deleted automatically — no sign-up, no watermark, and no email needed.

Why Convert WEBA to AMR?

WEBA is the audio-only stream pulled out of a WebM container, almost always carrying Opus or Vorbis at browser-record-quality bitrates (typically 64-128 kbit/s stereo). It's what Chrome's MediaRecorder API emits when you capture audio in the browser. AMR (Adaptive Multi-Rate), adopted by 3GPP as the standard cellular speech codec in October 1999, is the opposite end of the audio spectrum: a narrowband mono codec engineered to hit toll-quality voice at 12.2 kbit/s and survive at 4.75 kbit/s. Converting WEBA to AMR is almost always about feeding a voice-only system that won't accept anything else.

• Legacy phone voicemail and IVR uploads — Carrier voicemail platforms and many IVR/PBX systems (Asterisk, FreePBX) accept AMR or 8 kHz mono PCM and reject WebM/Opus outright. AMR-NB at 12.2 kbit/s is the safe default.
• Android phone voice memos — Android's built-in voice recorder has historically saved as .amr or .3ga; tools that import "voice notes" often expect that container. Converting a browser-recorded WEBA to AMR makes it look like a native phone memo.
• Forensic / call-center archival — Older recording systems store calls as AMR-NB to stay under a few hundred bytes per second. A 60-second WEBA at 96 kbit/s (~720 KB) becomes a ~91 KB AMR file at 12.2 kbit/s and ~36 KB at 4.75 kbit/s.
• MMS and low-bandwidth messaging — AMR fits inside the 3GP container used by MMS. If you've recorded a quick note in the browser and need to send it as an MMS attachment from a legacy gateway, AMR is the wire format.
• Embedded device speech input — Cheap microcontrollers and IoT speech-recognition modules often ship with AMR decoders in ROM but no Opus support. Converting first means you don't need to bundle libopus on the device.
• Speech-only transcription pipelines — Some on-prem ASR systems are tuned on AMR-NB telephony audio. Feeding them browser-quality Opus introduces frequency content above 3.4 kHz that the acoustic model never trained on; downsampling to AMR aligns the signal with the model.

WEBA vs AMR — Format Comparison

AMR Mode and Bitrate Quick Guide

If you don't know which mode the receiving system needs, pick 12.2 kbit/s AMR-NB. It is the de facto default and what every AMR decoder is required to support.

Frequently Asked Questions

Why does my AMR file sound muffled compared to the WEBA original?

AMR-NB only encodes the 200-3400 Hz band — the same range as a 1970s landline telephone. Anything above 3.4 kHz (the sparkle in cymbals, the "S" in sibilants, music harmonics) is filtered out before encoding. That is by design: the codec is optimized for intelligibility of human speech at low bitrates, not fidelity. If you need wider frequency response, choose AMR-WB (50–6400 Hz; up to 7000 Hz at the 23.85 kbps mode) by setting the constant bitrate to a wideband mode like 12.65 or 23.85 kbit/s, or convert to a different format such as WEBA to MP3 or WEBA to OGG.

Should I pick AMR-NB or AMR-WB?

AMR-NB (narrowband, 8 kHz sample rate) is what 99% of legacy systems expect — voicemail, MMS, older Android voice memos, telephony recordings. AMR-WB (wideband, also called G.722.2, 16 kHz sample rate) sounds noticeably clearer for speech but is only supported on newer VoLTE-capable phones and modern softphones. If you're feeding an unknown system, pick NB at 12.2 kbit/s. If you control the playback side and want better quality, pick WB at 12.65 or 23.85 kbit/s.

Will AMR work in my browser or in a normal media player?

Not directly in browsers — Chrome, Firefox, Edge, and Safari have no native AMR decoder. VLC, MPV, and Audacity (with FFmpeg) play AMR files. iOS plays AMR through QuickTime; Android plays them natively. If you need browser playback, AMR is the wrong target — convert to WEBA to MP3 or keep the file as WEBA/Opus instead.

How much smaller will my file get?

For 60 seconds of speech: a typical browser-recorded WEBA at 96 kbit/s Opus stereo is around 720 KB. At AMR-NB 12.2 kbit/s mono it becomes ~91 KB (about 8x smaller). At AMR-NB 4.75 kbit/s it's ~36 KB (20x smaller, but rough on quality). The savings come almost entirely from dropping stereo, narrowing the frequency range, and using a speech-tuned codec — not from a generic compression algorithm.

Is AMR good for music?

No. AMR is a CELP-family codec designed around a model of the human vocal tract; it cannot reproduce music acceptably. Drums turn into noise, melodic instruments warble, anything polyphonic falls apart. If your WEBA file is music or a podcast intro with music beds, use Opus, MP3, or AAC instead. AMR is for spoken voice only.

Why is my AMR file mono even though my WEBA was stereo?

The AMR specification only defines mono channel layouts. Both AMR-NB and AMR-WB downmix any stereo source to a single channel before encoding. The Audio Channel dropdown locks to Mono for that reason. If you need stereo voice (e.g., a two-party call recording with each party on a separate channel), convert to a stereo-capable format like WAV or M4A instead.

Can I use a custom bitrate that isn't on the preset list?

AMR uses a fixed set of modes — you can't pick an arbitrary number like 9 kbit/s. AMR-NB has eight discrete modes (4.75, 5.15, 5.90, 6.70, 7.40, 7.95, 10.2, 12.2 kbit/s) and AMR-WB has nine (6.60, 8.85, 12.65, 14.25, 15.85, 18.25, 19.85, 23.05, 23.85 kbit/s). The Constant Bitrate dropdown exposes the valid values. Any other input gets rounded to the nearest mode.

Does this converter store my voice recording?

No. Files upload over HTTPS, run through the conversion pipeline, and are deleted on a short timer — typically within a few hours of the download link expiring. We don't index file contents, don't train models on them, and don't require an account to convert.