Files · audio
Convert audio without uploading it.
Turn an audio file into WAV or MP3, choose the sample rate and channels, and download the result. Everything runs in your browser.
Audio file and output
Decoding and encoding happen on your device. Nothing is uploaded.
Up to 100 MB and 20 minutes. Input support depends on your browser.
Converted audio
Good to know
The result is a guide, not a guarantee.
This calculator runs entirely in your browser. Check the assumptions, keep the inputs realistic, and use the result as a starting point for a decision.
Audio conversion is lossless only when the output format preserves the source quality. MP3 is lossy, and converting an already-compressed file cannot restore missing detail.
Which audio formats can I use?
Input support depends on your browser, but most modern browsers can decode MP3, WAV, OGG, M4A/AAC and WebM audio. The output is WAV or MP3. If a file cannot be decoded, the browser will report an error before any conversion starts.
Is my audio uploaded to a server?
No. The file is read and decoded in your browser, and the converted file is created locally. Nothing is sent to simplytools.us or a third party.
Why does MP3 change my sample rate?
MP3 supports a fixed set of sample rates. If your source uses another rate, the converter switches to the nearest supported rate and tells you before converting. WAV can keep the original rate.
Does converting to MP3 improve quality?
No. MP3 is lossy, and converting an already-compressed file cannot restore detail that was removed earlier. It can only reduce the file size or make the format more compatible. For the best quality, keep a WAV or the original recording.
What do mono and stereo mean here?
Mono mixes the source to one channel and halves the raw audio data. Stereo keeps two channels (or duplicates a mono source). Choose mono for voice recordings and stereo for music or anything with a wider image.
What are the file limits?
The tool accepts files up to 100 MB and 20 minutes of audio at a time. Long files use more memory while decoding and encoding, so shorter clips are more reliable on mobile devices.
Which encoder does the MP3 option use?
MP3 encoding uses the open-source lamejs library, which is distributed under the LGPL-3.0 licence. WAV encoding is built into the tool and produces standard 16-bit PCM audio.