AMR to M4A Converter
Convert AMR to M4A online for free. Fast, secure, and high-quality conversion with no sign-up or software required.
Maximum file size is 1GB
How it works
Three steps to your converted file
Everything happens in your browser tab - upload, pick a format, download. The heavy lifting runs on our servers.
Upload your file
Drag and drop, click to browse, or paste a URL. Batches take up to 20 files at once - 230+ input formats across video, audio, image, document, and archive types.
Choose an output format
Pick from over a hundred output formats. Filter by category or search by name - every option is open to everyone, no account needed.
Convert & download
Hit Convert and grab your download link moments later. Originals are erased when the job completes; results are cleared within about an hour.
What is an AMR file?
The Adaptive Multi-Rate (AMR) audio codec is a compressed audio format optimized for speech coding, standardized by the 3rd Generation Partnership Project (3GPP) in 1999. Utilized heavily in GSM and UMTS mobile telephony, it employs the Algebraic Code-Excited Linear Prediction (ACELP) algorithm to dynamically adjust bitrates based on link quality, supporting eight discrete modes ranging from 4.75 to 12.2 kbit/s. The file structure encapsulates raw speech frames and supports Discontinuous Transmission (DTX), Voice Activity Detection (VAD), and Comfort Noise Generation (CNG) to maximize bandwidth efficiency in cellular networks.
How to open an AMR file
Native playback of AMR files is standard on Android devices and many legacy mobile platforms but is often unsupported on desktop operating systems like Windows and macOS without third-party codecs. Users should utilize the VLC media player, which leverages the FFmpeg library for decoding, or Audacity for editing purposes. Apple users can use QuickTime Player if the specific AMR component is installed, though cross-platform tools like VLC remain the most reliable solution.
AMR Technical Info
- Full Name
- Adaptive Multi-Rate Audio Codec
- Developed By
- 3GPP (3rd Generation Partnership Project)
- Initial Release
- 1999
- MIME Type
- audio/amr
What is an M4A file?
The M4A file extension denotes an audio-only MPEG-4 container, defined by ISO/IEC 14496-14 standards and typically encoded using Advanced Audio Coding (AAC) or Apple Lossless (ALAC). Originally popularized by Apple to differentiate audio content from standard .MP4 video files, the container utilizes an atom-based structure (e.g., ftyp, moov, mdat) to store audio streams and metadata. It serves as the successor to MP3, offering superior compression efficiency and fidelity at equivalent bitrates.
How to open an M4A file
M4A files are natively supported by the Apple ecosystem (iTunes, QuickTime, iOS Music) and Windows Media Player on modern Windows versions. Cross-platform compatibility is robust, with VLC Media Player, Audacity, and Winamp providing decoding capabilities. On Android devices, native players often handle M4A, though third-party apps like Poweramp ensure compatibility with ALAC-encoded variants.
M4A Technical Info
- Full Name
- MPEG-4 Audio
- Developed By
- Apple Inc. / MPEG
- Initial Release
- 2001
- MIME Type
- audio/mp4
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Convert AMR to M4A in seconds
Every AMR to M4A conversion runs on our servers, so your device stays fast and the output quality stays intact.
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No queue, no waiting. Files are processed on high-performance servers and returned in seconds, even for large files.
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Developer API
Convert AMR to M4A via API
Automate AMR to M4A conversions in three steps: create a job, upload your file, then poll for the result.
# 1. Create job
curl -X POST https://api.runconvert.com/v3/jobs \
-H "Authorization: Bearer YOUR_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"tag": "amr-to-m4a",
"tasks": {
"upload-file": {
"operation": "import/upload"
},
"convert": {
"operation": "convert",
"input": "upload-file",
"output_format": "m4a"
},
"export-result": {
"operation": "export/url",
"input": "convert"
}
}
}'
# 2. Upload your file (use upload_url from the response)
curl -X PUT "$UPLOAD_URL" --upload-file input.amr
# 3. Poll for result
curl https://api.runconvert.com/v3/jobs/$JOB_ID?include=tasks \
-H "Authorization: Bearer YOUR_API_KEY"Replace YOUR_API_KEY with your RunConvert API key. Get your free API key at runconvert.com/api.