M4A - WAV Conversion
Convert M4A to WAV, WAV to M4A, and convert multiple files at once
Features
Bidirectional M4A and WAV conversion
Automatically detect input files and convert them to the opposite format
Batch conversion of up to 20 files
Save individually or download all together as ZIP
Specify WAV output format
Choose sampling rate and mono or stereo
Choose M4A quality in 4 levels
Select from 96 to 256 kbps based on file size and audio quality balance
How to Use
Select conversion direction from dropdown
Choose from Auto, M4A → WAV, or WAV → M4A; default is Auto
Add audio files to convert
Add M4A or WAV by clicking or drag and drop; up to 20 files per session, 200 MB per file
Adjust save format in advanced settings
Change WAV sampling rate and channel, or M4A bitrate as needed
Execute conversion, preview, and save
Click Convert to process files sequentially, then preview in the player for each row before saving individually or as ZIP
Use Cases
Prepare meeting recordings for transcription
Convert M4A recorded on smartphone to WAV format that transcription software can read
Standardize materials for editing software
Convert M4A materials to uncompressed WAV for consistent handling in audio editing software
Share edited audio in lightweight format
Convert exported WAV to compressed M4A for easier sharing via chat or email
Prepare audio at specified sampling rate
Create WAV files matching the sampling rate or mono format required by submission destinations
Knowledge Base
Difference between M4A and WAV
M4A and WAV differ in whether audio is compressed before storage or stored as-is without compression.
- M4A：M4A is typically audio compressed using AAC codec, which removes inaudible components, then stored in an MP4 container. At 128 kbps, it takes approximately 1 MB per minute.
- WAV：WAV is an uncompressed audio format that records in PCM. At 44,100 Hz, 16-bit, stereo, it takes approximately 10 MB per minute.
Why audio quality doesn't recover when converting to WAV
During M4A compression, some audio components are discarded, and these discarded components cannot be restored when converting to WAV. While WAV increases file size by around 10 times, the audio quality remains the same as the original M4A. The benefit of converting to WAV is that it becomes easier to handle in editing software or transcription software.
How to choose sampling rate
Sampling rate is how many times per second audio is recorded. The highest frequency that can be recorded is up to half the sampling rate.
- 8,000 Hz：8,000 Hz is the same level as telephone audio, with only frequencies up to 4,000 Hz preserved, so it's limited to speech recognition use.
- 44,100 Hz：44,100 Hz is the same as audio CDs and can record sounds up to about 20,000 Hz, which is considered the upper limit of human hearing.
- 48,000 Hz：48,000 Hz is the standard value used in video and broadcast. Aligning materials to this value before importing into video editing software makes them easier to handle.
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 #387
M4A - WAV Converter Added. Convert multiple M4A and WAV files bidirectionally and specify WAV sampling rate
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