No. Converting an MP3 to WAV or FLAC does not improve its sound quality, because the detail the MP3 encoder threw away is gone and no format can bring it back. The new file sounds the same as the MP3 and is about ten times bigger. Convert to WAV or FLAC only when software or hardware needs that format, or to avoid losing more quality in later edits.
We tested this on two public domain recordings with the same FFmpeg build that runs the SearchSound.cloud audio converter. Below are the measured file sizes, what each conversion keeps and loses, and which format to pick for what.
Photo by Jumping Jax on Unsplash
Why doesn't converting MP3 to WAV improve quality?
Because MP3 is a lossy format and WAV is only a container for the samples you give it. When a song is encoded to MP3, the encoder removes sound it predicts you will not notice, mostly very high frequencies and quiet detail masked by louder sounds. Converting that MP3 to WAV decodes what is left and writes it out uncompressed. Nothing is added back.
A useful way to think about it: a WAV file usually holds plain linear PCM, the raw sample values, as the Library of Congress format description explains. FLAC is also lossless: audio "is compressed in FLAC without any loss in quality", in the words of the FLAC project. Both formats preserve whatever you put in exactly. If what you put in is an MP3, they preserve the MP3.
Two terms worth knowing:
- Lossy (MP3, AAC, M4A, OGG): smaller files, some audio permanently discarded at encode time.
- Lossless (WAV, FLAC): every sample kept. WAV stores it uncompressed; FLAC compresses it like a ZIP file, so it decodes back to identical samples.
What did we measure?
We took two public domain tracks from the Internet Archive, a dense, loud pop-rock song by Cyborg Hit Parade (3:17) and a quieter generative ambient track by Thomas Park (3:00). Both were prepared as CD-quality WAV masters: 16-bit, 44.1 kHz, stereo. We then ran them through the same FFmpeg WebAssembly build (@ffmpeg/core 0.12.10) and the same arguments that the converter on SearchSound.cloud uses, so the numbers match what you get from the site's default settings.
File size per minute by format
| Format | Bitrate (default settings) | Pop-rock track | Ambient track | Size vs WAV |
|---|---|---|---|---|
| WAV (16-bit, 44.1 kHz) | 1,411 kbps | 10.58 MB/min | 10.58 MB/min | 100% |
| FLAC | 806 to 972 kbps | 7.29 MB/min | 6.05 MB/min | 57% to 69% |
| M4A (AAC) | about 130 kbps | 1.00 MB/min | 0.99 MB/min | 9.4% to 9.5% |
| MP3 | 128 kbps | 0.96 MB/min | 0.96 MB/min | 9.1% |
| OGG (Vorbis) | about 106 to 109 kbps | 0.82 MB/min | 0.80 MB/min | 7.5% to 7.7% |
A few things stand out:
- WAV size is fixed by the math. 44,100 samples per second × 16 bits × 2 channels = 1,411,200 bits per second, or 10.58 MB per minute, whatever the music is.
- FLAC size depends on the music. The busy pop-rock track shrank to 69% of the WAV; the sparser ambient track to 57%. In both cases the FLAC decoded to exactly the same samples as the original WAV (we compared MD5 checksums of the audio).
- Lossy formats are roughly a tenth of WAV. MP3, M4A and OGG all landed between 7.5% and 9.5% of the WAV size at the converter's default bitrates.
What converting the MP3 back actually did
| Conversion | Pop-rock track | Ambient track | Sounds like |
|---|---|---|---|
| MP3 to WAV | 34.75 MB (same as the original WAV) | 31.85 MB (same as the original WAV) | The MP3 |
| MP3 to FLAC | 39.90 MB (115% of the original WAV) | 32.84 MB (103% of the original WAV) | The MP3 |
To see whether anything came back, we measured how much energy each file has above about 16.5 kHz, at the very top of the hearing range:
| File | Pop-rock: energy above 16.5 kHz vs original | Ambient: energy above 16.5 kHz vs original |
|---|---|---|
| Original WAV | 0 dB | 0 dB |
| MP3, 128 kbps | -11.8 dB | -12.1 dB |
| That MP3 converted to FLAC | -11.8 dB | -12.1 dB |
A drop of about 12 dB means roughly 94% of the energy in that top band was removed by the MP3 encoder. After converting the MP3 to FLAC, the figure is unchanged to the first decimal. The FLAC is a perfect copy of the MP3, missing treble included.
Why is my FLAC bigger than the WAV after converting from MP3?
Because the converter kept the decoder's extra precision. An MP3 decoder outputs floating point samples, not 16-bit integers. When FFmpeg writes those samples to FLAC with default settings, it stores them as 24-bit audio. The extra 8 bits per sample hold rounding detail that carries no musical information and compresses badly, so the FLAC can end up larger than a 16-bit WAV of the same song. In our test it was 3% and 15% larger.
Converting the same MP3 to WAV produced a 16-bit file of exactly the original WAV size. If you need a lossless file from an MP3 at all, a 16-bit WAV is the more compact choice here, but the better answer is usually to keep the MP3.
Can you convert WAV to MP3 without losing quality?
Not strictly: every MP3 encode discards some audio. What you can do is make the loss inaudible for most listeners. The FFmpeg MP3 encoding guide says LAME's variable bitrate quality settings 0 to 3 "will normally produce transparent results", meaning most people cannot tell them from the source.
A practical approach:
- Keep the WAV or FLAC master. Treat the MP3 as a delivery copy you can always remake.
- Encode once, from the lossless file. Never make an MP3 from another MP3 or from an AAC file.
- Use a higher bitrate when it matters. The converter on SearchSound.cloud writes 128 kbps MP3 by default, which is fine for previews, voice and sharing. For a high bitrate or VBR file, a desktop encoder such as FFmpeg (
ffmpeg -i song.wav -q:a 2 song.mp3) or Audacity gives you that control.
Is it bad to convert MP3 to AAC, M4A or OGG?
Yes, avoid it when you can. Each lossy encoder throws away a different set of details, so going from one lossy format to another stacks the losses. The FFmpeg high quality audio guide warns that transcoding from a lossy format to the same or a different lossy format "might degrade the audio quality even if the bitrate stays the same (or higher)", and recommends encoding from a lossless source instead.
If an app or device only accepts M4A and all you have is an MP3, converting is fine: you will lose a little more, often inaudibly. Just do it once, not back and forth.
When is converting MP3 to WAV actually useful?
Converting does not add quality, but it can solve real problems:
- Editing in software that prefers WAV. Some sample-based and older audio tools only import WAV or AIFF, and working in WAV avoids another lossy encode on every save.
- Hardware compatibility. Some samplers and older players only read uncompressed audio, so check the manual before converting a whole library.
- Repeated processing. If you will trim, pitch-shift or add effects several times, staying in WAV between steps means only one lossy encode at the very end.
- Burning an audio CD. Audio CDs store 16-bit, 44.1 kHz PCM, so burning software decodes MP3s to that format anyway.
Which audio format should you choose?
| You want to | Best format | Why |
|---|---|---|
| Archive a recording or a master | FLAC | Lossless, 57% to 69% of WAV in our test |
| Edit or produce music | WAV | Lossless, universally supported by editors |
| Share or play on any device | MP3 | Smallest widely compatible file |
| Pair audio with MP4 video | M4A (AAC) | Similar size to MP3; AAC is the usual audio codec in MP4 files |
| Get the smallest file at a similar bitrate | OGG (Vorbis) | Smallest in our test; check your app supports it |
How do you convert audio without uploading it?
Use a converter that runs on your own device. On SearchSound.cloud, the free audio converter runs FFmpeg inside your browser, so your files are processed locally and never sent to a server. It converts between MP3, WAV, FLAC, M4A, AAC and OGG, and handles several files at once.
- Open the converter for the pair you need, for example WAV to MP3, MP3 to WAV or WAV to FLAC.
- Drop in one or more files. The input format is detected from the file extension.
- Pick the output format and select Convert files.
- Download each converted file.
When you open the page, the converter first loads the FFmpeg engine (about 32 MB), so give it a moment on a slow connection. Large files take longer on slower devices. If you also need to cut the file, the audio trimmer works the same way, and if you are building a sample library, see how to organize and expand a music sample library or build a production workflow with free tools. Effects like the ones in our nightcore guide also export to MP3, WAV or FLAC.
FAQ
Does converting MP3 to FLAC improve quality?
No. FLAC is lossless, so it keeps exactly what the MP3 contains, including the missing high frequencies. In our test the MP3 and the FLAC made from it had identical energy above 16.5 kHz, while the FLAC was 11 to 13 times bigger than the MP3.
How much bigger is WAV than MP3?
A CD-quality WAV (16-bit, 44.1 kHz, stereo) is about 10.6 MB per minute, while a 128 kbps MP3 is about 0.96 MB per minute. That makes the WAV about 11 times bigger. A 320 kbps MP3 is about 2.4 MB per minute, so a WAV is still more than four times bigger.
Is FLAC better than WAV?
They sound identical, because both are lossless. FLAC files are smaller (57% to 69% of WAV in our test) and support tags such as artist and album, which makes FLAC the better choice for a music library. WAV is more widely accepted by audio editors and hardware, which makes it the safer choice for production work.
Is it safe to use an online audio converter?
It depends on where the processing happens. Many online converters upload your file to their servers, which matters for unreleased music or private recordings. A browser-based converter that runs FFmpeg locally, such as the one on SearchSound.cloud, never sends the file anywhere.
Will converting WAV to MP3 make my song sound worse?
Slightly, by design, but often not audibly. At 128 kbps the main measurable loss in our test was in the very top frequencies, above 16.5 kHz, at the very top of the hearing range. Keep the WAV, and encode at a higher bitrate if the MP3 is your final release format.