Which input formats are accepted?

WAV, M4A/AAC, FLAC, OGG/Opus and any MP4, MOV, MKV or WebM video. WMA and AMR are not decoded by browsers — use a desktop tool for those.

Is there a size or count limit?

No fixed count; each file can be up to about 2 GB, limited by your device’s memory.

What bitrate should I choose?

128 kbps for podcasts and voice, 192 kbps for most music, 320 kbps when you want the best MP3 can do. Converting a low-bitrate source to 320 kbps does not add quality.

Are my files uploaded?

No. Everything runs in your browser.

Audio Converters

Convert to MP3

Not sure what format your files are in? Drop them all here. Recordings, downloads, voice memos and videos come out as MP3 at the bitrate you choose.

Runs in your browser — files never leave your device.

Drop supported files here

or click to browse · paste from clipboard · up to 2000 MB each

Select files

Options

Bitrate

Channels

About Convert to MP3

MP3 is still the format that every player, car stereo, phone and messaging app accepts. When you have a mixed folder — an M4A voice memo, a WAV export, a FLAC album, a screen recording — one converter that takes them all saves opening five different tools.

Each file is decoded with the browser’s media stack and encoded with LAME (WebAssembly). Bitrate, sample rate and mono/stereo are set once for the whole batch; the result is a ZIP when there are several files.

How to convert files to MP3

Drop any mix of audio and video files onto the page.
Choose the bitrate (128 kbps for speech, 192–320 kbps for music).
Click Convert; download the MP3s individually or as one ZIP.

About the formats

WAV · Waveform Audio · .wav

Uncompressed PCM audio, the studio and archival standard: perfect quality, about 10 MB per minute at CD quality.

WAV is a container; almost all WAVs hold uncompressed 16- or 24-bit PCM.
A 4 GB file-size limit applies to standard WAV; long recordings use RF64 or BWF.
Because nothing is compressed, converting WAV to MP3 is the fastest way to shrink audio 10×.

M4A · MPEG-4 audio (AAC) · .m4a

Apple’s audio format from iTunes, Voice Memos and the Music app: AAC audio in an MP4 container, better than MP3 at the same bitrate.

M4A usually holds AAC; the .m4a from Apple Music purchases may be ALAC (lossless) instead.
Voice Memos on iPhone save M4A; many transcription and Android apps prefer MP3.
M4A supports chapters and cover art metadata.

AAC · Advanced Audio Coding · .aac

The successor to MP3 used by YouTube, Apple and broadcast: more efficient compression, usually wrapped in M4A or MP4.

A raw .aac file is an ADTS stream without a proper container, so some players cannot seek in it.
AAC at 128 kbps sounds roughly like MP3 at 160–192 kbps.
AAC is the mandatory audio codec in MP4 video.

FLAC · Free Lossless Audio Codec · .flac

Lossless compressed audio, about half the size of WAV with bit-identical playback; the format of choice for music archives and hi-fi downloads.

FLAC is open and royalty-free and supports up to 32-bit, 8 channels and 655 kHz.
Decoding FLAC is light, so most phones and players handle it; some car stereos and iTunes do not.
Converting FLAC to MP3 is lossy; keep the FLAC as the master.

Related conversions

Audio ConverterPopularOn-deviceAny audio format to any other, with bitrate control.WAV to MP3PopularOn-deviceUncompressed WAV to compact MP3 (about 10× smaller).Video to MP3PopularOn-deviceAny video file to an MP3 of its soundtrack.MP4 to MP3PopularPull the audio out of a video as an MP3.M4A to MP3PopularOn-deviceVoice memos and iTunes M4A to universal MP3.FLAC to MP3On-deviceLossless FLAC to MP3 for phones and cars, tags kept.

More in Audio Converters · All converters