You drop an audio file on the Audio Converter and it converts in place, in your browser: nothing is uploaded, the decode and the encode both run on your machine, and the converted file is ready to download the moment the spinner stops. One drop zone, three output formats, and two quality dials that re-encode the entire list the instant you touch them.
What the drop zone accepts
Click the drop zone or drag files onto it; multiple files go in at once. The format is detected from the MIME type and the extension: MP3, WAV, OGG, FLAC, M4A, AAC, WEBM, and AIFF are recognized by name, and anything else whose type starts with audio is given a chance to decode. Each file is decoded with the Web Audio API before it is encoded, so a file that will not decode is reported with a plain decode-failed notice while the rest of the list keeps working.
Three output formats, one 16-bit floor
MP3 is the default, with a bitrate select from 64 to 320 kbps that sits at 128 by default. WAV is 16-bit PCM with a 44-byte header, and FLAC is a lossless compression at level 5 whose encoder reaches the browser as a lazy 240 KB download, so a page that never converts to FLAC never pays for it. All three paths share one floor: the output is 16-bit, and a mono file comes out as dual-mono, with channel 0 duplicated into both channels rather than padded with silence.
The sample rate select, and the 48 kHz MP3 ceiling
The sample rate select offers Original, 22.05 kHz, 44.1 kHz, and 48 kHz, and choosing anything but Original resamples every file in the list. The MP3 encoder only accepts nine rates from 8000 to 48000 Hz, so a buffer sitting at an unsupported rate is halved repeatedly until it lands on one: 96 kHz becomes 48 kHz, and a rate that never lands on a supported value falls back to 44100 Hz. The FLAC path needs no resampling at all, because FLAC supports up to 655350 Hz natively.
A 3:24 file, converted four ways
Take a stereo demo.wav at 44.1 kHz, 16-bit, 3:24 long. That is 204 seconds, 8996400 samples per channel, 17992800 across both channels, and 35985644 bytes on disk once the header is in, which the file list shows as 34.32 MB. At 128 kbps the MP3 path writes 16000 bytes per second, or 3264000 bytes, about 3.11 MB, 91 percent smaller. At 320 kbps it writes 8160000 bytes, about 7.78 MB, 77 percent smaller. At 64 kbps it lands at 1632000 bytes, about 1.56 MB, 95 percent smaller. FLAC stays lossless and usually lands well under the WAV size, while resampling to 48 kHz before a WAV encode grows the file to 39168044 bytes, 37.35 MB, because more samples at 16 bits each is more bytes.
What the file list tells you
Each row carries a waveform sketch, the length as M:SS, the sample rate in kHz, the channel count, and the original size, then the converted line with the format, the channel count, and the new size. A mono file displays as 2ch, because the encoder duplicated it. The play button plays the original file, not the converted one, so it is a quick check that the right track is in the list. Download All saves every converted file one after another with a short stagger between saves, and the summary bar shows the total original size, the total converted size, and the overall percent change.
Where it fits in your audio workflow
Convert first, then trim or join: the Audio Merger and the Audio Trimmer both take the formats the converter outputs, and the audio merge guide walks through the combined flow. For the frames that come with a video, the Image Converter handles them the same way, and the Image Compressor shrinks them without changing the format. When the question is how big a file will get, the File Size Converter translates bytes to megabytes, and the image crop guide covers the other half of a typical media prep job.