AU
→
SPX

Convert AU to SPX Online

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

AU to SPX Converter

Upload your AU file to convert it to SPX format

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How to Convert AU to SPX

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

SPX is automatically selected as the output format

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Step 3: Start Conversion

Click the Convert button to start the conversion

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Step 4: Download Result

Download your converted SPX file when ready

Convert AU to SPX - Complete Guide

Converting AU to SPX 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. SPX is a audio format. Speex audio. Below is what actually changes in a AU→SPX conversion, what is preserved, and when SPX is the better choice than keeping AU.

What changes when you convert AU to SPX

  • The audio is re-encoded into the SPX 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: SPX 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 SPX format

SPX is a audio format. Speex audio.

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

Where SPX is strong: open, royalty-free codec tuned for speech; very small files for voice; low latency for real-time use.

Typical SPX uses: voice over IP and recordings, spoken-word archives, low-bandwidth speech.

What SPX keeps

  • SPX adds: open, royalty-free codec tuned for speech.

Things to watch out for

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

When to convert AU to SPX

  • Convert AU to SPX for voice over IP and recordings.
  • Convert AU to SPX for spoken-word archives.
  • Convert AU to SPX for low-bandwidth speech.

AU vs SPX — format comparison

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

AttributeAUSPX
TypeAudio fileAudio file
CompressionFlexible (lossy or lossless)Lossy
Web-friendlyNoNo
Typical file sizeMediumSmall
Best forlegacy Unix and Java system soundsvoice over IP and 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.

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Need the opposite conversion?

Convert SPX 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 AMRConvert AU to CAFConvert AU to MKAConvert AU to WVConvert AU to OGAConvert AU to DTSConvert AU to MP2
View all AU conversions →

Convert to SPX

Other formats you can convert to SPX

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

AU to SPX FAQ

Converting AU to SPX preserves the content faithfully; output also depends on the source file and any settings you choose.
Upload your AU file, confirm SPX as the output format, and click Convert. Job status is shown while the file is processed, then you can download the SPX 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 SPX conversion runs in your browser on any device — Windows, Mac, Linux, iOS, or Android — with uploads and downloads over HTTPS.
Processing time depends on file size, format, and queue load. The page shows job status while conversion runs.
Yes. You can add multiple AU files to a batch and process them together within the current file-size and credit limits.

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