Free Online Audio Converter
Convert audio between MP3, WAV, AAC, FLAC, OGG, M4A and WMA.
80+ formats · up to 50 MB each · 100 MB with a free account
| File name | Size | Convert to |
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Checking files and selected output formats.
About Audio Converter
Audio quality loss is audible rather than merely visible on inspection. A JPG at 60% quality often passes unnoticed; an MP3 at 96 kbps does not. Format, bitrate and codec therefore matter more on the first conversion here than in most other file categories.
The sections below cover the formats, the bitrates that go with them, and the sample-rate settings that sit underneath both.
Lossy and lossless
Lossy formats (MP3, AAC, OGG, Opus) discard frequency content the ear is unlikely to register, then compress what remains. A five-minute song occupies about 5 MB as MP3 against 50 MB as WAV. Lossless formats (FLAC, ALAC, WAV, AIFF) keep every sample, bit for bit, in much larger files.
Distribution to listeners uses lossy formats because bandwidth costs money. Editing, mastering and archiving stay lossless, because re-encoding a lossy file adds new loss on top of the loss already in it.
Format reference
| Format | Compression | Typical use | Compatibility |
|---|---|---|---|
| MP3 | Lossy | Music, podcasts | Plays anywhere |
| AAC (M4A) | Lossy | Apple ecosystem, streaming | All modern devices |
| OGG / Opus | Lossy | Voice, VoIP, games | Modern browsers, cross-platform |
| WAV | Uncompressed | Editing, sound design, samples | Every DAW opens it |
| FLAC | Lossless | Music archival, hi-fi | Most modern players and apps |
| ALAC (M4A) | Lossless | iTunes, Apple Music library | Apple ecosystem |
| AIFF | Uncompressed | Mac audio editing | Apple and pro audio tools |
| WMA | Lossy or lossless | Legacy Windows audio | Nearly obsolete |
Bitrate
For lossy formats, bitrate carries most of the quality. From the same encoder and source, 96 kbps sounds thin and washed out, 192 kbps sounds acceptable, and 320 kbps is transparent to most listeners on most equipment. AAC matches MP3 quality at roughly 25% less bitrate, and Opus at roughly 40% less than AAC.
Reasonable starting points: 128 kbps AAC for voice-only podcasts, 192 kbps MP3 for casual music, 320 kbps MP3 or AAC where quality matters, and uncompressed WAV for anything that will be edited again.
Sample rate and bit depth
Sample rate sets how often the audio is measured: 44.1 kHz for CDs, 48 kHz for video, 96 kHz for high-resolution studio work. Bit depth sets the dynamic range, 16-bit for CDs and MP3 against 24-bit in the studio. Dropping 96 kHz to 44.1 kHz is inaudible for most material, and 24-bit to 16-bit is inaudible outside critical listening on studio monitors.
For distribution, 44.1 kHz and 16-bit is the standard and gives the smallest file with no perceptible loss. For editing, keep the source values until the final export.
Which format to convert to
- For a podcast: MP3 at 128-192 kbps for voice, higher with music beds. Universal player support is worth more than the space AAC would save.
- For distributing music: MP3 at 320 kbps or AAC at 256 kbpsboth effectively transparent.
- For importing to a DAW: WAVwhich every DAW handles with no re-encoding between edits.
- For archiving a library: FLAChalf the size of WAV and bit-for-bit identical to the source.
- For voice memos over WhatsApp or Signal: send what you have. The apps re-encode to Opus regardless.
- For audio pulled out of a video: MP4 usually carries AAC and MKV something less common. Convert to MP3 or WAV depending on what happens to the audio next.
Common mistakes
Re-encoding a lossy file at a higher bitrate does not recover quality. The information the original MP3 discarded is gone, so the result is a larger file that sounds the same or slightly worse.
Converting to WAV for storage is the other one. WAV is lossless, but so is FLAC at about half the size. WAV is worth it only when a tool requires it.
How to convert an audio file - step by step
Same flow for every audio tool below, WAV to MP3, M4A to MP3, MP3 to WAV, FLAC to anything.
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1
Pick the tool by source and target
Start with what you have. Voice memo from your phone (M4A)? Music library rip (FLAC)? Studio session export (WAV)? Each dedicated tool page is tuned for that specific pair with sensible defaults already applied, you don't have to know what a bitrate is to get a good result.
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2
Upload your file (or drop a batch)
Free-tier uploads are capped at 100 MB; a full-album FLAC needs Pro. Pro handles files up to 1 GB and batch jobs of up to 20 tracks at once, which is roughly a full mixtape or podcast season.
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3
Set the quality - where it applies
The tool page picks a reasonable default for the target format. Override the bitrate only if you have a reason: lower for smaller files (voice content), higher for music where quality matters. Sample rate and bit depth almost always match the source unless you need to conform to a specific spec.
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4
Convert and download
Audio conversion is fast, a 5-minute track typically converts in a couple of seconds. Individual files download directly; batches ship as a ZIP. Both the upload and the converted files are permanently deleted from our servers within 1 hour.
Common mistakes
- Higher bitrate on a lossy source is a waste. Converting a 128 kbps MP3 to 320 kbps makes a bigger file that sounds no better. The information is already gone.
- Match the sample rate to the destination. Audio for video edits is almost always 48 kHz. Audio for CD-style playback is 44.1 kHz. Mismatched rates can cause subtle desync in long files.
- Preserve metadata when converting music. ID3 tags carry artist, album, track number, and album art. Losing them means your library shows "Unknown Artist" for every converted track.
- Voice memos don't need music-grade quality. A 128 kbps MP3 or 96 kbps AAC is more than enough for spoken content, anything higher is wasted bytes.