How do I convert WMA to MP3?

Drop the .wma file onto the converter at the top of this page, keep 128 kbps or pick another bitrate (64 or 96 kbps is enough for voice), press Convert to MP3 and download the file. It runs in your browser on a computer or phone, with no software and no account, for files up to 100 MB and 30 minutes.

Why won't my WMA file play on my phone or Mac?

WMA is Microsoft's Windows Media Audio format, stored in an ASF file. iPhones, Macs and most browsers do not include a WMA decoder, while MP3 plays on practically everything. Converting once gives you a copy that opens anywhere.

Can it convert WMA files from an Olympus or other dictaphone?

Yes, when the recorder saved WMA Standard, which is what voice recorders such as the Olympus WS-300M wrote. Copy the .wma files off the recorder's folders and drop them here. A file saved with the WMA 9 Voice codec is the exception: the converter names it and asks you to export it again.

Why does the converter say my WMA is copy-protected?

Its header carries Windows Media DRM, which locks the audio to the licence it was sold or ripped with. No converter can read protected audio without that licence, so the page stops rather than producing silence. Unprotected WMA files convert normally.

Is my WMA file uploaded?

No. The decoder is downloaded to your browser and the WMA is read, decoded and encoded on your own device, so a confidential dictation never leaves it. The page loads the site's analytics, which count events such as a finished conversion, never the file or its name.

WMA to MP3 Converter

A free WMA to MP3 converter for the recordings phones, Macs and car stereos will not play: dictations from an older digital voice recorder, Windows recordings and WMA music files. The WMA is decoded on your device, not uploaded, and the MP3 plays everywhere.

Drop your WMA file here or click to browse

WMA Standard, Pro or Lossless, up to 100 MB and 30 minutes.

The file is converted in your browser and is not uploaded.

How to convert WMA to MP3

Three steps, no software to install and no account.

1
Drop the WMA
Drag a .wma file from the recorder's folder or your music library onto the converter, or click to pick it. The page reads the file's header first: its length, its codec, and whether it is copy-protected.
2
Pick a bitrate
128 kbps is the default. A dictation or a voice memo sounds the same at 64 or 96 kbps and makes a smaller file; choose 192 or 320 kbps for music.
3
Convert and download
The page decodes the WMA and encodes the MP3 on your computer or phone. Play the preview, then download the MP3 under the WMA's name with an .mp3 ending.

Where WMA files come from

WMA is Microsoft's Windows Media Audio format. It was common on Windows PCs and on the voice recorders sold alongside them.

Digital voice recorders
Several older dictaphones recorded straight to WMA. Olympus's quick guide for the WS-300M, for one, says it records in WMA, in folders named DSS_FLDA to DSS_FLDE on the recorder.
Windows recordings and exports
Recordings made or exported with Windows Media tools, from interviews to voicemail saved on a PC, often ended up as .wma files in Documents or Music.
Music ripped on Windows
CDs ripped with Windows Media Player in its WMA setting fill many old music folders. Phones and car stereos are far more likely to play an MP3 copy.
Archives and handovers
A box of old interview recordings, a predecessor's dictations, a family archive: an MP3 copy opens on any device for the next person who needs it.

How big the MP3 will be

An MP3's size is its bitrate times its length. A WMA works the same way, so a dictation recorded at a low bitrate gets bigger, not better, as a 128 kbps MP3: pick a bitrate near the WMA's own (Windows shows it under Properties, Details, Bit rate).

MP3 bitrate	Per minute	Per 30 minutes
MP3, 64 kbps	469 KB	13.7 MB
MP3, 96 kbps	703 KB	20.6 MB
MP3, 128 kbps	938 KB	27.5 MB
MP3, 192 kbps	1.4 MB	41.2 MB
MP3, 320 kbps	2.3 MB	68.7 MB

MP3 bytes = kbps × 1,000 × seconds ÷ 8. 1 MB = 1,048,576 bytes.

Which WMA files convert

WMA is a family of codecs inside the same ASF file type. The converter checks which one your file uses before decoding.

WMA Standard (v1 and v2)
The everyday WMA of voice recorders and ripped CDs, mono or stereo. Converts.
WMA Pro and WMA Lossless
Pro can hold 24-bit and multichannel audio; Lossless keeps every sample. Both convert; 5.1 audio is folded down to stereo for the MP3.
WMA 9 Voice
A speech codec Microsoft made for very small voice files. This converter cannot decode it and tells you so; save the file again as WMA Standard, WAV or MP3 from the software that made it.
Copy-protected WMA
Files locked with Windows Media DRM, such as some music bought from older online stores, cannot be read by any converter without the licence. The page detects the protection and stops.

Why your browser needs help with WMA

Browsers play MP3, AAC, WAV, Ogg and FLAC, but not Windows Media: the containers MDN lists as supported on the web do not include ASF, the format a .wma file is stored in, and Chromium's own audio decoder rejected a WMA file in our test.

So this page brings its own decoder. It loads FFmpeg's open-source WMA decoders, compiled to WebAssembly (the @audio/decode-wma package, LGPL-2.1), the first time you convert a file, then reads the WMA and writes the MP3 on your device. That works the same in Chrome, Edge, Firefox and Safari, and on a phone.

MP3 is lossy like WMA Standard and Pro, so the copy is a re-encode: at 128 kbps it is rarely audible on speech. Keep the WMA if it is a master you care about, especially a WMA Lossless file.

Converting an old recording to read what was said?

For a dictation or an interview, the MP3 is a step on the way to the words. For new recordings, ParrotNotes records on your phone and gives you the transcript, a summary and the action items, free for 100 minutes of recording a month.

Get Started Free

Related tools

WMA to MP3 FAQ

Sources

WMA to MP3 Converter

How to convert WMA to MP3

Drop the WMA

Pick a bitrate

Convert and download

Where WMA files come from

Digital voice recorders

Windows recordings and exports

Music ripped on Windows

Archives and handovers