WAV vs MP3: Which Format Should You Edit and Share?
Use a lossless editing master when you can, then make a smaller delivery file once. Converting MP3 to WAV is useful for editing, but it does not bring missing detail back.
By the fix.fm team · Published · Updated
Keep an editing master and a delivery copy
WAV and MP3 solve different problems. A typical PCM WAV stores the decoded samples directly. MP3 stores a compressed representation that discards some information to reduce size. The best choice depends on what you are doing next, not on which extension looks more professional.
For editing and archiving, keep the highest-quality original available. For sharing or podcast delivery, use a format the destination accepts at a sensible bitrate. A WAV made from an MP3 contains the decoded MP3 sound; it does not undo its compression.
Compare size with the settings included
File-size comparisons only make sense when you include duration, channels, sample rate, bit depth or bitrate. Here is the arithmetic for a ten-minute recording, using decimal megabytes and ignoring small headers and metadata.
| Example | Calculation | Approximate size |
|---|---|---|
| Mono PCM WAV, 48 kHz, 16-bit | 600 × 48000 × 1 × 2 bytes | 57.6 MB |
| Stereo PCM WAV, same settings | 600 × 48000 × 2 × 2 bytes | 115.2 MB |
| MP3, 192 kbps total bitrate | 600 × 192000 ÷ 8 bytes | 14.4 MB |
MP3's bitrate is for the encoded stream, not a separate 192 kbps allocation to each channel. The same total bitrate spread over two channels has more work to do than over one. Variable-bitrate files will not have exactly the constant-bitrate size shown here.
WAV is a container and can carry formats beyond basic PCM. The examples here specifically mean uncompressed PCM WAV, which is what our audio converter exports. Its output is 16-bit; it does not preserve a source's 24-bit depth simply because the extension remains WAV.
Conversion cannot restore discarded detail
If the original take is MP3, decoding it to WAV can be useful. You can pass a stable PCM editing copy between programs and avoid another lossy export at each stage. But the original MP3's discarded information is already gone.
Repeated MP3 exports can add new artifacts. Make edits from the original or the lossless working master, then encode the delivery copy once. Renaming a file from .mp3 to .wav does not convert its contents; a real converter decodes and writes a new file.
The Audacity manual's file-format explanation distinguishes uncompressed, lossless-compressed and lossy-compressed formats. Lossless compressed audio such as FLAC is another useful archival option, although fix.fm does not currently export FLAC.
Match the export to the destination
For an editing handoff, ask whether the receiver wants PCM WAV and which sample rate and bit depth they need. For a public feed, follow the host's accepted delivery formats. Apple's audio guidance separates subscriber uploads from RSS feed audio; do not assume a file accepted in one workflow is accepted in every other workflow.
Our converter makes 16-bit WAV or 192 kbps MP3 from audio the browser can decode. It does not copy chapters, artwork or tags, and a video input becomes an audio-only file. The browser may resample during decoding, so use a dedicated editor if preserving the source sample rate is a requirement.
Check more than whether the file opens
Open the exported file, listen to a quiet phrase and a loud consonant, and check its start and end. Use the LUFS meter on that delivery copy if level matters. A lossy export can alter true peaks even when you did not touch the volume.
If you only need a short excerpt, trim the recording before its final export. That tool decodes MP3 rather than copying compressed frames, so its MP3 download is a re-encode. Choose WAV for a sample-accurate clip, then encode once in the delivery workflow if needed.
Keep both the original and the final working master. A smaller delivery file is useful for listeners; a dependable master is useful when tomorrow's edit needs one more sentence.