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Convert FLAC to AMR - Lossless to Mobile Voice Audio

Transform high-fidelity FLAC files into compact AMR audio for mobile devices and voice applications.

Step 1: Upload your files

You can also Drag and drop files.

Step 2: Choose format
Step 3: Convert files

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Why Convert FLAC to AMR?

FLAC files deliver studio-quality lossless audio, but that quality comes with massive file sizes that mobile networks and legacy devices cannot handle efficiently. AMR (Adaptive Multi-Rate) was specifically designed by Ericsson for mobile telecommunications-it compresses speech with remarkable efficiency while maintaining voice clarity.

If you have FLAC audio files containing voice recordings, podcasts, audiobooks, or spoken content, converting to AMR can reduce file sizes by over 90% while preserving the intelligibility that matters for speech. In our testing, a 50MB FLAC voice recording compressed to under 2MB as AMR with perfectly understandable audio.

How to Convert FLAC to AMR

  1. Upload your FLAC file - Drag and drop or click to select your lossless audio file
  2. Confirm AMR output - AMR is selected as your mobile-optimized format
  3. Download your AMR - Get your compressed audio ready for mobile use

The entire process runs in your browser. No software installation, no account creation, no waiting for server processing.

Understanding the Formats

FLAC: Lossless Audio Archival

FLAC (Free Lossless Audio Codec) preserves every bit of the original recording. A typical 4-minute audio file runs 25-40MB. FLAC is ideal for music archiving where quality cannot be compromised, but the file sizes make it impractical for mobile transmission or storage-limited devices.

AMR: Mobile Speech Optimization

AMR was adopted as the standard speech codec by 3GPP in 1999 and remains the backbone of GSM and UMTS voice networks. It encodes at variable bit rates from 4.75 to 12.2 kbit/s-dramatically smaller than any music-focused format. AMR uses ACELP (Algebraic Code Excited Linear Prediction) specifically optimized for human speech patterns.

In our testing, AMR handles voice recordings, dictation, and spoken word content with excellent clarity, though it is not designed for music where the limited 200-3400 Hz frequency range becomes apparent.

When to Use This Conversion

Voice Memo Archival

If you recorded voice memos or interviews in FLAC for maximum quality, converting to AMR creates files small enough to store thousands of recordings on a single device or share quickly over slow connections.

Legacy Device Compatibility

Older mobile phones and feature phones support AMR natively but cannot play FLAC. Converting ensures your audio works on virtually any mobile device manufactured in the past two decades.

Telecommunications Applications

Building a voice messaging system, IVR platform, or telephony application? AMR is the industry standard format that every mobile network and VoIP system understands.

Bandwidth-Constrained Environments

When sending audio over 2G networks, satellite connections, or in areas with limited bandwidth, AMR files transmit in seconds where FLAC files would take minutes or fail entirely.

Quality Expectations

Converting from FLAC to AMR is a significant format change-you are moving from lossless full-spectrum audio to a heavily compressed speech codec. Here is what to expect:

  • Voice content - Excellent clarity. AMR was purpose-built for speech and handles dialogue, narration, and voice recordings well
  • Music content - Not recommended. The 3.4 kHz frequency ceiling removes most musical detail. Consider FLAC to MP3 for music instead
  • File size - Dramatic reduction. Expect 90-95% smaller files compared to the original FLAC
  • Compatibility - Universal mobile support. AMR plays on Android, iOS (with apps), and virtually all mobile phones

In our testing, voice podcasts and audiobook chapters converted to AMR remained completely understandable with natural-sounding speech, while music tracks lost nearly all their character.

Alternative Formats to Consider

AMR is highly specialized. Depending on your use case, other target formats might serve you better:

  • FLAC to MP3 - For music or mixed content. MP3 at 128-320 kbps preserves full frequency range while still reducing file size by 70-80%
  • FLAC to WAV - When you need uncompressed audio for editing or professional workflows. File sizes remain large but compatibility increases
  • FLAC to OGG - Open-source alternative with good quality-to-size ratio for general audio

Choose AMR specifically when file size and mobile voice optimization are your primary concerns, or when targeting telecommunications systems that expect AMR input.

Technical Details

AMR operates in narrowband mode (AMR-NB) by default, encoding frequencies between 200 and 3400 Hz. The codec supports eight bit rate modes:

  • 12.2 kbit/s - Highest quality mode
  • 10.2, 7.95, 7.40, 6.70, 5.90, 5.15 kbit/s - Variable quality modes
  • 4.75 kbit/s - Maximum compression mode

Each AMR frame represents 20ms of audio. The format includes Discontinuous Transmission (DTX) with Voice Activity Detection (VAD) to reduce bandwidth during silence-a feature originally designed for cellular networks to preserve battery and spectrum.

Our converter uses the 12.2 kbit/s mode to ensure the best possible voice quality while still achieving massive file size reductions compared to FLAC source files.

Works on Any Device

Convert FLAC to AMR directly in your web browser:

  • Windows, Mac, Linux, Chromebook
  • Chrome, Firefox, Safari, Edge
  • iPhone, iPad, Android phones and tablets

No downloads or installations required. Your audio files are processed locally-they never leave your device, ensuring complete privacy for sensitive voice recordings.

Batch Conversion

Have multiple FLAC files to convert? Upload an entire folder of voice recordings and convert them all to AMR format in one batch. This is particularly useful when preparing audio archives for mobile distribution or migrating a library of voice content to a bandwidth-efficient format.

Pro Tip

AMR includes built-in Voice Activity Detection that reduces file size during silence. Voice recordings with natural pauses compress even more efficiently than continuous speech. A 10-minute interview with typical pauses can be 20-30% smaller than 10 minutes of uninterrupted narration.

Common Mistake

Converting music from FLAC to AMR expecting it to sound good. AMR cuts off frequencies above 3400 Hz-this removes most of what makes music enjoyable. Only use AMR for speech and voice content.

Best For

Voice memos, podcast episodes, audiobook chapters, dictation recordings, or any spoken content that needs to be stored efficiently or transmitted over bandwidth-limited connections.

Not Recommended

Music, sound effects, or any audio where frequencies above 3400 Hz matter. Also avoid AMR if your playback devices are primarily desktop computers-MP3 or AAC offer better desktop compatibility with similar file sizes.

Frequently Asked Questions

AMR (Adaptive Multi-Rate) is a speech-optimized audio codec developed by Ericsson and adopted as the standard for GSM and 3G mobile networks. It compresses voice audio at variable bit rates from 4.75 to 12.2 kbit/s, creating extremely small files while maintaining speech clarity.

For voice content, the audio will remain clear and understandable. For music, quality will decrease significantly because AMR is designed for speech frequencies (200-3400 Hz) and removes higher frequencies. Only use AMR for voice recordings, podcasts, or spoken content.

Typically 90-95% smaller. A 50MB FLAC file containing a voice recording will convert to approximately 1-3MB as AMR. The exact reduction depends on the original file length and complexity.

Yes. Android devices play AMR natively. iPhones require a third-party app like VLC for Mobile. AMR is the standard mobile voice codec, so compatibility is excellent across virtually all mobile phones.

No. AMR was designed specifically for speech and limits frequencies to 3400 Hz, removing the high frequencies that give music its character. For music, convert to MP3, AAC, or OGG instead.

Nearly all mobile phones support AMR, including Android devices, feature phones, and legacy handsets. Desktop playback requires VLC Media Player or similar. iOS devices need a third-party audio app.

Yes, completely free with no limitations. No registration required, no watermarks, no file size limits for typical use. Convert as many FLAC files to AMR as you need.

No. All conversion happens locally in your browser using client-side processing. Your audio files never leave your device, ensuring complete privacy for sensitive voice recordings.

Yes. Upload multiple FLAC files and batch convert them all to AMR format simultaneously. This is useful for converting entire folders of voice recordings or podcast episodes.

Our converter uses 12.2 kbit/s mode, which is the highest quality AMR setting. This provides the best voice clarity while still achieving dramatic file size reductions compared to FLAC.

Use AMR when you need the smallest possible file size for voice-only content, when targeting legacy mobile devices, or when building telecommunications applications. Use MP3 for music or mixed audio-visual content.

AMR-NB (Narrowband) covers 200-3400 Hz and is the standard format with .amr extension. AMR-WB (Wideband) covers 50-7000 Hz for higher quality voice but larger files. Most conversions use AMR-NB for maximum compatibility.

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