Convert MP4 to AAC Online
MP4 is a digital multimedia container that stores video, audio, subtitles, and metadata. AAC is the successor to MP3, offering better efficiency at the same bitrates. AnyConvert converts MP4 to AAC securely without installing desktop software.
MP4 to AAC Converter
Convert your MP4 files to AAC format quickly and easily. Upload your file and download the result.
Max file size: 50MB
Why convert MP4 to AAC?
Switching from MP4 helps you avoid encoding high-quality h.265/av1 inside mp4 may face patent/licensing concerns. AAC excels at superior quality to mp3 at bitrates of 128 kbps and below, making it a better fit when clients or platforms expect streaming services like apple music and youtube.
Advanced Audio Coding also offers supports multichannel audio and higher sample rates up to 96 khz. That means your converted files stay useful for streaming services like apple music and youtube and broadcast applications requiring efficient multi-channel audio.
MP4 strengths
- Excellent compatibility with browsers, TVs, mobile devices, and OTT platforms
- Supports multiple audio tracks, subtitles, and chapter markers
- Efficient streaming via fragmented MP4 and adaptive bitrate protocols
AAC advantages
- Superior quality to MP3 at bitrates of 128 kbps and below
- Supports multichannel audio and higher sample rates up to 96 kHz
- Mandatory audio codec for many streaming standards and mobile OSes
Key differences
| Feature | MP4 | AAC |
|---|---|---|
| Compression | Lossy | Lossy |
| Transparency / Alpha | Not applicable | Not applicable |
| Typical file size | Compact (lossy compression) | Compact (lossy compression) |
| Best suited for | Web video delivery and social media uploads and Mobile playback and offline downloads | Streaming services like Apple Music and YouTube and Broadcast applications requiring efficient multi-channel audio |
| Standard | Open, royalty-free specification | Open, royalty-free specification |
Before you convert
- Keep a backup of your original file before converting so you can roll back if needed.
- Export any critical metadata (EXIF, IPTC, ID3, or captions) because AAC may not retain it.
- Review known pain points: Not ideal for lossless intermediate editing due to GOP-based compression. Adjust your source file accordingly.
- Note the target resolution and frame rate to avoid unexpected stretching or stutter.
Quality tips
- Start with a high-quality setting (85–90%) and only reduce it if file size targets demand it.
- Pick a bitrate that matches your destination: 128 kbps for speech, 192–256 kbps for music, 320 kbps for archive copies.
- Download the result immediately and open it in the target application to verify everything matches expectations.
Where AAC fits best
Once you have the converted file, you can plug it straight into streaming services like apple music and youtube, broadcast applications requiring efficient multi-channel audio, and mobile apps that demand high quality with compact file sizes. AAC is the format teams expect in those environments, so you spend less time re-exporting or explaining compatibility issues.
Common AAC use cases
- Streaming services like Apple Music and YouTube
- Broadcast applications requiring efficient multi-channel audio
- Mobile apps that demand high quality with compact file sizes
Tools that open AAC
- ffmpeg (libfdk_aac)
- Adobe Audition
- Logic Pro
Frequently asked questions
Does converting MP4 to AAC reduce quality?
Yes, AAC uses lossy compression. Start with the highest quality setting available and compare the converted file against your original. If you need a perfect copy, keep the MP4 source as an archive.
Which bitrate should I pick for AAC?
Match the bitrate to the destination. 96–128 kbps is fine for speech, 192 kbps balances quality and size for music, and 256–320 kbps keeps critical mixes transparent.
Is there a file size limit for converting MP4?
Yes—uploads up to 150 MB convert reliably in the browser. For larger assets, split them into smaller segments first so the process stays responsive.