AU
→
AMR

Convert AU to AMR Online

Convert AU to AMR online. Start with free daily conversions, no install, no watermarks, and visible job status.

AU to AMR Converter

Upload your AU file to convert it to AMR format

Loading converter...

How to Convert AU to AMR

Follow these simple steps

1

Step 1: Upload Your File

Upload your AU file by dragging and dropping or clicking to browse

2

Step 2: Select Output Format

AMR is automatically selected as the output format

3

Step 3: Start Conversion

Click the Convert button to start the conversion

4

Step 4: Download Result

Download your converted AMR file when ready

Convert AU to AMR - Complete Guide

Converting AU to AMR stays in the audio file family but changes the traits that decide size, quality, transparency, editability, or device support. AU is a audio format. Sun audio. AMR is a audio format. Adaptive Multi-Rate. Below is what actually changes in a AU→AMR conversion, what is preserved, and when AMR is the better choice than keeping AU.

What changes when you convert AU to AMR

  • The audio is re-encoded into the AMR format. Because re-encoding is not free, start from the highest-quality source you have and keep quality settings high.
  • Expect a smaller output file: AMR is typically more space-efficient than AU for the same content.

About the AU format

AU is a audio format. Sun audio.

  • Compression: mixed
  • Opens with: VLC, Audacity, FFmpeg

Where AU is strong: simple legacy format from Sun/NeXT systems; stores uncompressed PCM or companded mu-law/A-law audio; easy to read and parse.

Typical AU uses: legacy Unix and Java system sounds, older audio archives.

About the AMR format

AMR (Adaptive Multi-Rate) is an audio format optimized for voice recordings. It is commonly used by mobile phones for voice memos and recordings.

  • Full name: Adaptive Multi-Rate
  • Developer: 3GPP
  • Compression: Lossy compression
  • Opens with: VLC, QuickTime, FFmpeg

Where AMR is strong: very small files optimized for speech; the standard codec for mobile voice recordings; low bitrate ideal for narrow bandwidth.

Typical AMR uses: phone voice recordings, voicemail and push-to-talk audio, MMS voice messages.

What AMR keeps

  • AMR adds: very small files optimized for speech.

Things to watch out for

  • One AMR limitation to keep in mind: poor quality for music.

When to convert AU to AMR

  • Convert AU to AMR for phone voice recordings.
  • Convert AU to AMR for voicemail and push-to-talk audio.
  • Convert AU to AMR for MMS voice messages.

AU vs AMR — format comparison

A quick side-by-side of the structural differences between AU and AMR, so you can confirm this is the right conversion for your file:

AttributeAUAMR
TypeAudio fileAudio file
CompressionFlexible (lossy or lossless)Lossy
Web-friendlyNoNo
Typical file sizeMediumSmall
Best forlegacy Unix and Java system soundsphone voice recordings

Privacy & Security

Files are handled for the conversion you request. Uploads and downloads use HTTPS/TLS, and temporary files are cleared after the processing and deletion window.

Add this AU to AMR converter to your site

Put a working AU to AMR converter on your own blog or website — free to embed. Both options below include a small link back to FreeFastConverter.

Embeddable widget (iframe)

Paste this where you want a live converter. Visitors can convert AU to AMR without leaving your page:

Widget Embed Codeiframe

Simple link badge

Prefer a lightweight button instead? Copy this HTML badge:

HTML Badge CodeLink

Need the opposite conversion?

Convert AMR to AU

Other AU Conversions

More formats you can convert AU to

Convert AU to MP3Convert AU to WAVConvert AU to AACConvert AU to OGGConvert AU to FLACConvert AU to M4AConvert AU to WMAConvert AU to AIFFConvert AU to OPUSConvert AU to AC3Convert AU to CAFConvert AU to MKAConvert AU to WVConvert AU to SPXConvert AU to OGAConvert AU to DTSConvert AU to MP2
View all AU conversions →

Convert to AMR

Other formats you can convert to AMR

Convert MP3 to AMRConvert WAV to AMRConvert AAC to AMRConvert OGG to AMRConvert FLAC to AMRConvert M4A to AMRConvert WMA to AMRConvert AIFF to AMRConvert OPUS to AMRConvert AC3 to AMRConvert CAF to AMRConvert MKA to AMRConvert WV to AMRConvert SPX to AMRConvert OGA to AMRConvert DTS to AMRConvert MP2 to AMR
View all AMR conversions →

AU to AMR FAQ

Converting AU to AMR preserves the content faithfully; output also depends on the source file and any settings you choose.
Upload your AU file, confirm AMR as the output format, and click Convert. Job status is shown while the file is processed, then you can download the AMR result.
Yes. You can start with free daily conversions, with no signup required for your first jobs and no watermarks on the output. Accounts and paid plans are available for higher-volume work.
No. The AU to AMR conversion runs in your browser on any device — Windows, Mac, Linux, iOS, or Android — with uploads and downloads over HTTPS.
AMR (Adaptive Multi-Rate) is an audio file format. AMR files can be played with various audio players and media applications.
Upload your AMR audio file to the converter, select your desired output format, and click Convert. The job status appears while the audio is processed.
You can start with free daily conversions. Accounts and paid plans are available for higher-volume work, and downloaded files are not watermarked.
You can convert AMR to proof-backed audio outputs such as MP3, WAV, AAC, OGG, FLAC, M4A, WMA, AIFF, OPUS, AC3, AMR, AU, CAF, MKA, WV, SPX, OGA, DTS, and MP2 when the source format is public-supported.
Yes! Our AMR converter works on any device including smartphones and tablets.
Choose the bitrate or output setting that fits your file-size and playback needs. Lossy formats can reduce detail compared with the source.

Related tools

Convert AU to AMR Now

Start with 10 free daily conversions. No signup required for your first file jobs.

Convert Now