A voice memo from your iPhone won’t open in the software on your PC. A WAV recording is too large to email. An app only accepts MP3. More often than you’d expect, the problem isn’t the audio itself — it’s the file format.
This guide shows you how to convert M4A, WAV, FLAC and other audio files to MP3 or WAV with the free Audio Format Converter. Your audio is converted in your browser and never uploaded.
I built this after a meeting recording wouldn’t load into a transcription tool because of its format. I wanted a quick way to convert audio without sending it anywhere.
Audio formats in a nutshell
Audio can be saved in many formats. These are the four you’ll run into most:
- MP3: the most widely used format. Small files that play on almost any device or app
- M4A (AAC): common on Apple devices, including iPhone Voice Memos. Better quality than MP3 at the same size, but some older software can’t open it
- WAV: uncompressed. No quality loss, but large files. Best for importing into editing software
- FLAC: compressed without losing quality. Popular for music, but not supported everywhere
When in doubt: MP3 for everyday use, WAV for editing software.
What this tool does
- Opens WAV, MP3, M4A, FLAC, OGG and other formats your browser can play
- Converts to MP3 or WAV
- Lets you choose the MP3 quality (bitrate)
- Converts several files at once, with a single ZIP download
- Works entirely in your browser — your audio is never uploaded
How to use it
Step 1. Choose your audio files
Open the Audio Format Converter and choose the files you want to convert. You can select several at once.
Step 2. Choose the format and quality
Under Convert to, pick MP3 or WAV. For MP3, also choose a Bitrate. For meetings and voice memos, 128kbps (standard) is plenty. For music, choose 192kbps or higher.
128kbps is plenty for meetings and voice memos
Step 3. Convert
Click Convert. The first time, the MP3 encoder takes a moment to download.
Step 4. Save the results
Converted files appear in a list. Save them one at a time, or click Download all as ZIP to get them all at once. Each file keeps its original name with the new extension.
For audio you’re going to transcribe, MP3 at 128kbps makes almost no difference to accuracy — and the smaller file loads faster.
When this comes in handy
- Using iPhone recordings on Windows: turn Voice Memos M4A files into MP3s that open anywhere
- Sending large recordings: shrink a WAV meeting recording to an MP3 small enough to email or share in chat
- Preparing audio for transcription: convert files that Audio Transcription can’t open into MP3 first
- Video editing: convert MP3 or FLAC sources into WAV for your editor
FAQ
Can my iPhone record voice memos as MP3?
No. The built-in Voice Memos app always saves M4A files. Its settings only let you choose the quality (compressed or lossless). If you need MP3, convert the recording afterward.
Does converting again and again reduce quality?
Compressed formats like MP3 and M4A lose a little quality every time they’re re-encoded. Keep the original file and convert just once, straight to the format you need. Converting to WAV doesn’t change the quality.
How much smaller will my file get?
As a rough guide, an hour of CD-quality WAV is about 600 MB, while the same audio as a 128kbps MP3 is about 58 MB. For meeting recordings, converting to MP3 typically cuts the size to around a tenth.
Things to watch out for
- M4A and FLAC output aren’t available: the tool converts to MP3 and WAV only
- Formats your browser can’t play won’t open: for unusual formats, use dedicated conversion software
- Long recordings take time: for recordings several hours long, a computer is the better choice
- Want to cut long silences? Remove them with the Silence Trimmer to make the file even smaller
Summary
Audio that won’t open or is too big to send can almost always be fixed by converting it to MP3 or WAV. With the Audio Format Converter, you can convert in bulk right in your browser, without uploading anything.
Start by converting one of your iPhone voice memos to MP3.
