How do I convert an MP4 file to AU?

Upload your MP4 file to the converter, select AU as the destination format, and click 'Convert'. The tool extracts the audio track and encodes it as a Sun AU file. Once the conversion finishes, download the AU file to your device.

Why would I convert MP4 to AU instead of keeping MP4?

MP4 is a digital multimedia container that typically uses AAC or MP3 audio compression, while AU is an uncompressed audio format (PCM) developed by Sun Microsystems. Converting MP4 to AU is useful for legacy Unix applications, Java applets, or audio editing workflows that require raw, uncompressed audio. It eliminates codec dependencies and ensures the highest possible audio quality.

What happens to the audio quality and settings during MP4 to AU conversion?

The converter preserves the original audio channels (mono/stereo) and lets you choose the sample rate (e.g., 44.1 kHz or 48 kHz) and bit depth (16-bit or 24-bit). It decodes the MP4's AAC or MP3 audio track and re-encodes it to AU PCM; this means the exact bitrate of the source is replaced by your chosen PCM settings. Video tracks are discarded, and metadata like ID3 tags may not be carried over.

Is MP4-TO-AU free to use?

Yes, MP4-TO-AU on LetsConvert is 100% free with no registration or hidden fees required.

Are my uploaded files safe and secure?

Yes! File privacy and security are guaranteed. Basic conversions run locally in your browser. Files sent for server processing are automatically deleted within 1 hour.

Does this converter work on mobile phones and tablets?

Yes! MP4-TO-AU works seamlessly across iPhone, Android, iPad, Mac, Windows, and Linux browsers without installing any app.

Is there any software installation required?

No software or browser extension installation is needed. All conversions are performed directly online.

MP4➔AU· 100% Free & Full HD

MP4-TO-AU

Convert MP4 to AU to get lossless PCM audio. Ideal for legacy Unix apps, audio editors, and Java. Extract audio from video instantly.

★★★★★

4.7 / 5.0(18 user ratings)

Rate this tool:

🎬

Choose Mp4 video file or drag & drop here

Supports up to 50MB · Hardware accelerated transcode

Browse Video

Or import from:

📢

Share MP4-TO-AURecommend this free tool to your friends & colleagues

📁

MP4

MPEG-4 Part 14 Video Container

Source Format

MP4 is the undisputed global standard digital video format. Supported across every computer, smartphone, smart TV, browser, and social platform, it encapsulates high-efficiency H.264/H.265 video and AAC audio with unmatched playback reliability.

Category: Digital Video

MIME Type: video/mp4

Developer: Moving Picture Experts Group (MPEG)

Best For: Social media video, YouTube uploads, mobile video recording, web video streaming, and video archiving.

✨

AU

AU File Format

Target Output

AU is a standardized digital file format supported by LetsConvert. Convert AU files securely, privately, and instantly online with zero software installation, bank-grade encryption, and automatic 60-minute file purging.

Category: Data & Media File

MIME Type: application/au

Developer: Standard Organization

Best For: Converting and managing AU files across devices and applications.

💡 Technical Guide & Conversion Insights

Why Convert MP4 to AU?

Converting from MP4 (MPEG-4 Part 14 Video Container) to AU (AU File Format) is essential when you need enhanced compatibility, reduced file size, or specific feature support. While MP4 is ideal for Social media video, YouTube uploads, mobile video recording, web video streaming, and video archiving., AU offers superior advantages for Converting and managing AU files across devices and applications.. Our secure online conversion engine ensures that all your MP4 file attributes, geometry, quality, and metadata are seamlessly preserved during the transformation into AU.

● MP4 Key Advantages:

✓100% universal hardware and software playback compatibility
✓High compression efficiency with excellent HD/4K fidelity
✓Optimal format for YouTube, TikTok, Instagram, and web embedding

● AU Key Advantages:

★Standard format compatibility
★Fast online conversion processing
★Zero software install required

MP4 vs AU Comparison Table

Detailed technical differences and capabilities between MPEG-4 Part 14 Video Container and AU File Format.

Feature / Attribute	MP4	AU
Primary Format Name	MPEG-4 Part 14 Video Container	AU File Format
Primary File Category	Digital Video	Data & Media File
Standard MIME Type	video/mp4	application/au
Core Developer / Standard	Moving Picture Experts Group (MPEG)	Standard Organization
Optimal Use Case	Social media video, YouTube uploads, mobile video recording, web video streaming, and video archiving.	Converting and managing AU files across devices and applications.

❓ Common Questions

Frequently Asked Questions (MP4 to AU)

Everything you need to know about converting MP4 to AU with LetsConvert.

To convert your MP4 file to AU, upload your file by dragging and dropping it into the upload box or selecting it from your device. Adjust any optional quality or dimension settings, then click 'Convert'. Your converted AU file will be ready for instant high-speed download within seconds.

🛡️

100% Secure & Automatic File Purging

Your MP4 files are encrypted with 256-bit SSL and permanently deleted from our servers within 60 minutes.

● Zero File Storage

How to Convert MP4-TO-AU

Select or drop your Mp4 file.

Initiate the AU conversion process.

Download your converted AU file.

⚡ Related Video Tools

MP4-TO-AU

MP4

AU

Why Convert MP4 to AU?

● MP4 Key Advantages:

● AU Key Advantages:

MP4 vs AU Comparison Table

Frequently Asked Questions (MP4 to AU)

100% Secure & Automatic File Purging

How to Convert MP4-TO-AU

Related Video Converters (145)

3G2 to MP4

3GA to MP4

3GP to AU

3GP to MP4

3GPP to MP4

AAC to MP4

AIF to MP4

AIFC to MP4

AIFF to MP4

ALAC to MP4

AMR to MP4

APE to MP4

ASF to AU

ASF to MP4

AU to 3GP

AU to ASF

AU to AVI

AU to FLV

AU to GIF

AU to M2TS

AU to MKV

AU to MOV

AU to MP4

AU to MPEG

Explore All VIDEO Pairs & Formats

⚡ Convert from MP4 to other formats: