WMV to AMR Converter

How to Convert WMV to AMR Online

1. Upload Your WMV File: Drag and drop or click "+ Add Files" to select a Windows Media Video clip. Batch upload is supported, useful for a folder of old screen recordings or recorded webinars.
2. Pick a Quality Preset or Constant Bitrate: Default is the "Highest" preset, which maps to 12.2 kbit/s — the toll-quality AMR-NB mode. Drop to 7.40 kbit/s for a smaller file at telephone quality, or 4.75 kbit/s for the smallest voice-memo footprint. Custom Constant Bitrate exposes all eight standard AMR-NB modes (4.75, 5.15, 5.90, 6.70, 7.40, 7.95, 10.2, 12.2 kbit/s).
3. Audio Channel, Sample Rate, and Trim (Optional): AMR-NB is mono at 8000 Hz only — both controls stay locked to "Mono" and "8000 Hz" to match the codec spec (RFC 4867). Use Trim to cut a specific Start and Duration window from the WMV timeline before extraction so you don't carry silence or filler into the final clip.
4. Convert and Download: Click "Convert" and download the resulting .amr file. Everything runs in your browser session — no sign-up, no watermark, and the source WMV never leaves your machine in plain view.

Why Convert WMV to AMR?

WMV is a Microsoft container (ASF) that typically wraps a Windows Media Video stream alongside a Windows Media Audio (WMA) track. AMR — Adaptive Multi-Rate Narrowband — is a 3GPP speech codec adopted in October 1999, designed for the 200–3400 Hz telephony band and used by GSM/UMTS networks and most mobile voice-memo apps. Converting WMV to AMR throws away video and music fidelity on purpose: you get a tiny, mono, 8 kHz speech file built for archives, voicemail-style playback, or feeding into telephony tooling.

• Voice-memo / voicemail archives — A one-hour WMV screen recording at 128 kbit/s WMA produces roughly a 55 MB audio track; the same hour at AMR 12.2 kbit/s is about 5.5 MB, and at 4.75 kbit/s drops to roughly 2.1 MB. Ideal for long-term retention of meeting narration where you only need words, not music.
• Legacy GSM / IVR systems — Many enterprise IVR menus, call-center recorders, and feature-phone voicemail platforms still ingest AMR-NB natively because it was the default 3GPP speech codec for 2G/3G voice.
• Push-to-talk and dispatch radio uploads — PTT services that pre-date Opus often expect AMR frames (20 ms, 160 samples). Extracting narration from a WMV training video into AMR lets you drop it straight into a dispatch playlist.
• Speech-to-text pre-processing — Speech recognizers tuned on telephony data (such as legacy CallMiner pipelines) accept AMR directly. Stripping the WMV video and music down to a narrowband mono stream avoids resampling artifacts in the ASR front end.
• Storage-constrained handsets and embedded devices — Old Symbian, Java ME, and entry-level Android phones expose AMR as the only built-in speech codec. AMR ringtones and notification clips still work where MP3 licensing was stripped.
• Forensic and compliance excerpts — Court and HR workflows that demand "voice only, no video, smallest possible" routinely standardize on AMR-NB because the codec range is fixed and the file format is documented in RFC 4867.

WMV vs AMR — Format Comparison

AMR-NB Bitrate Quick Guide

Frequently Asked Questions

Why is the sample rate locked to 8000 Hz and mono?

That's the AMR-NB specification, not a tool limitation. RFC 4867 and 3GPP TS 26.071 define AMR-NB as a single-channel 8 kHz codec with a fixed 200–3400 Hz passband and 20 ms frames of 160 samples. If you need 16 kHz wideband speech (AMR-WB / G.722.2), that's a separate codec — convert to that format instead, or use AAC/Opus if you want stereo and music fidelity.

Will the music or background score in my WMV come through cleanly?

No. AMR-NB throws away everything above ~3.4 kHz and is heavily tuned for the human glottal/voice model. Music, applause, and even sibilant "s" sounds in narration will sound muffled or warbly. If the WMV has music you want to keep, convert to MP3 or AAC instead — try WMV to MP3 or WMV to WAV for the lossless route.

What does "Highest" map to, and is it really the best AMR mode?

The "Highest" Quality Preset selects 12.2 kbit/s, which is the top AMR-NB mode and matches GSM Enhanced Full Rate (GSM-EFR). It's the best AMR-NB can do; anything higher quality requires AMR-WB (up to 23.85 kbit/s, 16 kHz) or a different codec entirely.

Why is my AMR file so much smaller than the original WMV?

A typical 1080p WMV at 4 Mbit/s holds ~30 MB per minute. AMR-NB at 12.2 kbit/s is roughly 92 KB per minute — about 330× smaller. The conversion drops the video stream entirely, downmixes to mono, downsamples to 8 kHz, and throws away the music band. That's the point of AMR: speech-only storage.

Can I open the .amr output on iPhone or modern Android?

Android plays .amr natively in the system media player. iPhone does not have first-party AMR playback in the Files app or stock players since iOS 11 dropped legacy codec support; you'll need VLC for iOS, a transcription app, or convert to M4A first. macOS Finder does not preview AMR either — QuickTime stopped bundling the AMR codec after macOS Snow Leopard.

Should I use AMR for voicemail or transcription?

For voicemail destined for a GSM/UMTS gateway or a Cisco / Avaya IVR, yes — AMR-NB is the lingua franca. For modern cloud transcription (Whisper, Google Speech-to-Text, AWS Transcribe), AMR is accepted but FLAC or 16 kHz WAV usually gives 5–15% lower word error rate because the recognizer keeps the higher frequencies. Use AMR when the downstream system demands it; otherwise pick a wideband container.

What about AMR-WB — when should I prefer that instead?

AMR-WB (G.722.2) handles 50–7000 Hz at 16 kHz sample rate with bitrates from 6.6 to 23.85 kbit/s. It's the codec behind VoLTE / HD Voice on most carriers since around 2014. Pick AMR-WB if you need clearer "s" and "f" sounds and the receiving system supports it; pick AMR-NB only if you must match legacy 2G/3G voicemail or a device that explicitly requires it.

Can I trim the WMV before extraction so I only get the spoken section?

Yes. Open Trim in Advanced Options and set a Start time (HH:MM:SS) and Duration. The conversion will extract only that window into AMR — no need to make an intermediate cut. For a finer cut after conversion, the Audio Cutter tool also reads AMR.

Are there file-size or count limits?

There's no per-account daily quota or watermark. Browser-side processing means very large WMV files are limited mainly by your device RAM. For multi-gigabyte source files (long screen recordings, conference captures), expect longer in-browser load times — chunk the source with a trim window if needed, or compress with Compress AMR after conversion to shrink existing AMR archives.