How to Batch Convert WAV Files to MP3 or AIFF

WAV, MP3 or AIFF: what is the difference?

The three formats do different jobs. The question is not which one sounds better in general, but which one the next step of your workflow needs.

WAV

In recording and post-production, WAV files usually hold uncompressed PCM audio. They are the everyday format of field recorders, DAWs and editing software, and often carry production metadata such as BWF timecode and iXML. More in WAV file format explained.

MP3

MP3 is a lossy compressed format. Files are much smaller, which makes them convenient for listening copies, client previews, references and quick delivery. An MP3 is not a replacement for a production master.

AIFF

AIFF is an uncompressed audio format commonly used for PCM audio. It plays much the same role as WAV, and is useful when an application, a workflow or a delivery specification asks for AIFF. See also WAV vs AIFF.

When should you batch convert WAV to MP3?

• sending lightweight listening copies,
• client previews of a set of recordings,
• reference files for an editor or a director,
• quickly sharing many recordings,
• creating smaller copies of a large WAV collection,
• any delivery where MP3 is specifically requested.

When many WAV files need the same MP3 conversion, Batch WAV to MP3 runs it on the whole set in one queue, while the WAV masters stay untouched.

When should you batch convert WAV to AIFF?

• an application you use requires AIFF,
• a delivery specification asks for AIFF files,
• you need an uncompressed alternative to WAV,
• material is moving into an AIFF-based workflow and must stay uncompressed.

WAV and AIFF can both contain the same uncompressed PCM audio. Converting between them is usually about compatibility or a delivery format, not about improving sound quality. Batch WAV to AIFF does that conversion for a whole set of files.

How to batch convert WAV files to MP3

1. 1. Open Batch WAV to MP3

   Open Batch WAV to MP3.

2. 2. Add your WAV files

   Drop several WAV files at once, or add more later. The tool accepts WAV files only. A file that is not a WAV, a damaged file, or a file with more than two channels is marked as failed with a message, and the rest of the queue carries on.

3. 3. Review the queue and settings

   MP3 files are encoded at 320 kbps. The only setting is the sample rate: Source (the default) keeps each file's rate when MP3 allows it, or you can pick a fixed rate. Mono files stay mono and stereo files stay stereo. Each MP3 keeps the original filename, so Interview_01.wav becomes Interview_01.mp3.

4. 4. Choose where to save

   In browsers that support output-folder selection, you can choose a folder and each converted file is written there as soon as it is ready. Otherwise, files are saved using the browser's normal download workflow.

5. 5. Convert the batch

   Start the queue. Files are converted one after another, and each MP3 is saved as soon as it is ready, before the next file starts. Failed or cancelled files can be retried when the batch has finished.

How to batch convert WAV files to AIFF

1. 1. Open Batch WAV to AIFF

   Open Batch WAV to AIFF.

2. 2. Add your WAV files

   Drop several WAV files at once, or add more later. The tool accepts WAV files only; a file that is not a WAV or cannot be read is marked as failed, and the rest of the queue carries on. Multichannel WAV files keep all their channels.

3. 3. Review the queue and settings

   Sample rate and bit depth both default to Source, which keeps each file's properties. You can instead pick a target sample rate, and a bit depth of 16 or 24-bit. With both set to Source, each AIFF keeps the original filename (Take_03.wav → Take_03.aiff). When you choose a target rate or depth, the name describes it, for example Take_03_48k_24bit.aiff.

4. 4. Choose where to save

   In browsers that support output-folder selection, you can choose a folder and each converted file is written there as soon as it is ready. Otherwise, files are saved using the browser's normal download workflow.

5. 5. Convert the batch

   Start the queue. Files are converted one after another, and each AIFF is saved as soon as it is ready, before the next file starts. Failed or cancelled files can be retried when the batch has finished.

Which format should you choose?

Converting only because you can is rarely useful. If the next person or application accepts your WAV files, send the WAVs.

What happens to sample rate and bit depth?

Batch WAV to AIFF

With the default settings, each AIFF keeps the sample rate and bit depth of its WAV. 16-bit and 24-bit sources stay 16-bit and 24-bit. The AIFF output goes up to 24-bit, so a 32-bit WAV is written as 24-bit. If you pick a target sample rate or bit depth, every file in the queue is converted to it.

Batch WAV to MP3

MP3 supports sample rates up to 48 kHz. With Source selected, 44.1 kHz and 48 kHz files keep their rate. Higher rates are written at the closest standard rate of the same family: 88.2 kHz and 176.4 kHz become 44.1 kHz, and 96 kHz and 192 kHz become 48 kHz.

MP3 does not store audio as PCM samples with a bit depth the way WAV and AIFF do, so there is no such thing as a "24-bit MP3". Its size and detail are described by the bitrate, here 320 kbps. More in MP3 bitrate explained. To check a file's rate, depth and channels before or after converting, use the Audio Inspector. If you need a sample rate change while staying in WAV, use the Batch Sample Rate Converter.

What happens to audio quality?

WAV to AIFF. When the sample rate and bit depth stay the same, WAV to AIFF is primarily a format conversion: the PCM audio is written into an AIFF file without improving or adding information to the source.

WAV to MP3. MP3 encoding is lossy compression. It creates smaller files by discarding part of the audio information according to the codec. That is fine for listening copies and references, but you should normally keep the original WAV masters. See WAV vs MP3 quality.

What happens to metadata?

Both batch converters write the audio, the sample rate and the channels, but they do not carry WAV production metadata into the new files. BWF information such as timecode and originator, iXML scene and take details, markers and INFO tags are not written into the MP3 or AIFF outputs, and the MP3 files contain no ID3 tags.

If that information matters to your workflow, keep the original WAV files alongside the converted copies. For more on what is stored in a production WAV, read BWF metadata explained.

Batch conversion for large folders

• Files are processed one after another, not all at the same time.
• Only the file being converted is held in memory.
• Each finished file is saved as soon as it is ready; no ZIP is needed at the end.
• If you stop the batch, the files already finished are saved.
• Keep the browser tab open until the queue has finished.

This makes long queues practical, but it does not remove every limit: very long or high sample rate recordings still need memory, and older or low-memory devices may struggle with them. For very large jobs, split the folder into smaller batches. Where the browser supports it you can choose an output folder; otherwise files arrive as normal browser downloads.

Are my audio files uploaded?

Your audio files are processed locally in your browser. Each file is read, processed and written locally, one after another.

Batch conversion vs converting one file

Batch makes sense when you have:

• many files,
• the same conversion goal for all of them,
• a repeated delivery workflow,
• folders of recordings.

For one file, a one-off conversion, or files that each need different settings, the single-file tools are simpler: WAV to MP3 and WAV to AIFF.