M4A - MP3 Conversion & Reverse Conversion
Convert M4A to MP3, MP3 to M4A, and batch convert multiple files with instant playback preview
Features
Bidirectional M4A and MP3 Conversion
Auto-detect input file format and convert to the opposite format
Batch Convert Up to 20 Files
Save files individually or download all at once as ZIP
Instant Playback Preview After Conversion
Preview audio quality with the player in each row before saving
Quality Selection by Output Format
3 bitrate levels for MP3, 4 levels for M4A
How to Use
Select Conversion Direction from Dropdown
Choose Auto, M4A → MP3, or MP3 → M4A; default is Auto
Add Audio Files to Convert
Add M4A or MP3 by clicking or drag-and-drop; up to 20 files per batch, max 200MB per file
Adjust Quality in Advanced Settings
Change bitrate for MP3 and M4A as needed
Convert, Preview, and Save
Click Convert to process files sequentially, preview with the player in each row, then save individually or as ZIP
Use Cases
Prepare Voice Memos for Transcription
Convert M4A from iPhone to MP3 format compatible with transcription services or sharing recipients
Play Music on Legacy Devices
Convert M4A from iTunes to MP3 playable on car audio systems and older music players
Audio for Apple Applications
Convert your MP3 files to M4A for iPhone ringtone creation and easier compatibility with Apple ecosystem apps
Batch Share Lecture Recordings
Standardize multiple lectures and interview recordings to MP3 format and share as a single ZIP file
Knowledge Base
Difference Between M4A and MP3
M4A and MP3 are both compressed audio formats that reduce file size by removing inaudible portions, but they differ in compression method and typical use cases.
- M4A：M4A typically contains audio compressed with AAC format wrapped in an MP4 container, used as the standard format for iPhone voice memos and iTunes library imports.
- MP3：MP3 is an audio compression format widely adopted since the 1990s, compatible with most playback devices and software including car audio systems and legacy music players.
Which Bitrate (kbps) Should I Choose?
Bitrate is the amount of data used per second of audio; higher values provide better sound quality but also increase file size proportionally.
- 128 kbps：128 kbps uses approximately 1MB per minute and suits voice recordings or situations where file size must be minimized.
- 192 kbps：192 kbps uses approximately 1.4MB per minute and offers a balanced trade-off between quality and file size for everyday music listening.
- 320 kbps：320 kbps is the highest bitrate available for MP3, using approximately 2.4MB per minute.
Why Repeated Conversions Degrade Quality
Both M4A and MP3 remove inaudible audio components during each conversion, so repeated conversions between M4A and MP3 gradually reduce quality with each iteration. Once audio data is discarded, it cannot be recovered even with higher bitrates.
Safety and Privacy
Runs entirely in your browser
Your input data is processed only within your browser and is never sent externally.
Processing only in your browser
Audio file conversion is processed entirely within your browser, and input data is not sent to any server.
Communications encrypted with HTTPS
Page loading is also encrypted by TLS, and content cannot be read by third parties.
No transmission to third parties
Input content is not sent to external services such as ad networks or trackers.
No automatic saving of results
Converted audio and input suggestions are not stored on the server.
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Updates
- update #386
Added M4A - MP3 conversion and reverse conversion. Supports batch conversion and playback after conversion
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