The free online audio converter changes a sound file between MP3, WAV, AAC, M4A, FLAC, OGG and Opus. It pulls the audio out of a video too. Because it runs in the browser, the files are never uploaded.
Audio format work by OnlinePCApps since 2013
A sound file in the wrong format will not play, takes too much room or will not load into an app. The free online audio converter puts it in the format the job needs.
An M4A from an Apple device or an OGG from a download will not open in every player or car stereo. Converting to MP3, the most widely supported audio format, makes the track play almost anywhere.
A WAV recording is huge, near 10 MB a minute, which fills a phone or a mail limit fast. Converting to MP3 or AAC at a sensible bitrate cuts the size to a tenth while the ear hears little difference.
A lecture, a song or a podcast often arrives as a video when only the sound is wanted. Dropping a video in and choosing MP3 or M4A saves the audio on its own, ready for a music app or a podcast player.
Drag the sound files onto the panel above, or browse to them on the device. One track or a whole batch can go in together, and a video works too when only its audio is needed.
Pick the format to convert to, such as MP3, AAC, WAV or FLAC. For a lossy format a bitrate up to 320 kbps sets the balance of size against fidelity, while a lossless one keeps the full sound.
Save the converted track, or grab a whole batch as a ZIP. The original files stay untouched, so the same audio can be converted again to another format or bitrate at any time.
To convert audio means re-encoding the same waveform under a different format. That work stays on the device.
The same sound is re-encoded from one format into another, from M4A to MP3, WAV to FLAC, OGG to AAC and the rest. The source format is recognised automatically, which leaves only the output to pick.
A lossy format such as MP3, AAC or OGG takes a bitrate up to 320 kbps that trades file size against fidelity. A lossless format such as WAV or FLAC keeps the full sound and takes no bitrate at all.
Drop a video in and the picture track is dropped, leaving the sound to save as MP3, M4A or WAV. This turns a music video, a lecture clip or a voice recording into an audio file on its own.
A start and end time trims a track to the part that matters before it converts. A whole batch can go together and come back as a ZIP, so an album or a set of voice notes is done in one pass.
To convert audio, to change an M4A to MP3 and to turn a WAV into FLAC all name the same step. A search for audio converter or MP3 converter reaches this tool, and the source files are left untouched.
Re-encoding moves the sound into a fresh format, and the notes below shape what comes out.
| The case | Result | What happens and why |
|---|---|---|
| MP3, AAC, M4A | clean | The common lossy formats convert between one another and play almost anywhere. |
| WAV and FLAC | lossless | Both keep the full sound, WAV uncompressed and FLAC compressed to about half. |
| OGG and Opus | open formats | The open lossy formats are read and written, Opus being the most efficient. |
| WMA, AIFF, ALAC | read as input | Older Windows and Apple lossless formats are read and converted to a common target. |
| Extract from video | audio only | A video is read and the picture dropped, saving the sound as MP3, M4A or WAV. |
| Bitrate | up to 320 kbps | A constant or variable bitrate up to 320 kbps trades detail against size. |
| Sample rate | 44.1 or 48 kHz | CD audio sits at 44.1 kHz and video sound at 48 kHz, both carried across. |
| Channels | mono or stereo | Kept as the source has them, or set to mono to roughly halve the size of speech. |
| Lossy to lossless | no restore | An MP3 turned to WAV stops further loss but cannot rebuild detail already gone. |
| Tags | where supported | Title, artist and album tags carry across when both formats support them. |
| Where it runs | on the device | The audio is re-encoded in the browser, so nothing is uploaded. |
The Same Sound, a Different Format
An audio format is a way of packing the same waveform into a file. A conversion reads the sound out of one format and writes it into another, which is why the track sounds the same while the file, its size and its reach change. The honest points sit around lossy against lossless. MP3, AAC, OGG and Opus are lossy, small because they drop sound the ear is least likely to notice. A bitrate up to 320 kbps sets how much is kept. WAV holds the full uncompressed audio and runs near 10 MB a minute, while FLAC compresses that same lossless sound to about half without losing a thing. One rule holds throughout: turning a compressed MP3 into a lossless WAV stops any further loss but cannot add back the sound the earlier compression removed, and repeating lossy conversions stacks the loss each time. The best result starts from the highest-quality original on hand. The references below set out the main formats.
Each one changes the format of a sound file. The trade is real, and a recording is often a personal thing.
| Point of comparison | This tool Converted in the browser On the device | Hosted converter Uploaded and converted on a server |
|---|---|---|
| Where the files go | Never leave the device | Uploaded to a server |
| Price and caps | Free with no file cap | Free tier often capped |
| Hour-long lossless masters | Held in tab memory | Reads straight from disk |
| Deep tag and cover editing | Carries the basic tags | Full tag and art editor |
| A library of thousands | A set at a time in the browser | The whole library at once |
Those last three rows favour a desktop tool, since an hour-long master, a deep tag edit and a library of thousands each call for more than a browser tab holds. For a handful of everyday tracks the first two rows are what count. The audio never moves off the machine, and the conversion is free without a cap.
FFmpeg, built to WebAssembly, decodes and re-encodes each track inside the browser, so the work is client-side and the audio stays on the machine that opened it. Nothing is handed to a remote server to finish it.
A recording can be a private thing, a voice memo, an interview or a demo never meant to sit on an outside server. A hosted converter must send every file up to a server to change its format, far more exposure than a simple format swap warrants.
Each of these changes a sound file's format. They part ways on effort, on price and on whether the file travels.
Apple Music, VLC and FFmpeg each sit on the machine, yet one leans on its own library, one buries the option and one lives in the terminal. This page keeps that local footing while folding batch conversion and audio extraction into a page that needs no setup.
A few notes point to the format that fits.
MP3 suits wide playback on any device. AAC or M4A suits Apple gear at a smaller size. WAV or FLAC suits archiving and editing where the full sound matters, and the destination usually points to one.
A lossy format at 320 kbps sounds close to the source at a fair size, while 128 kbps saves room with a softer sound. For speech a lower bitrate is fine, and for music a higher one holds the detail.
Turning a compressed MP3 into a lossless WAV stops further loss but cannot bring back sound already gone. For the cleanest result, start from the highest-quality source on hand.
The browser handles a set of tracks in memory, which fits the audio in hand. A library of thousands, or hour-long lossless masters that run to gigabytes, belongs on the desktop edition, which reads from disk and re-encodes the whole set in one pass.
Point it at a folder of tracks and every file is re-encoded to the target format in a single run, saved beside the original.
Hour-long lossless masters and concert recordings that run to gigabytes are handled straight from disk, past what a browser tab holds.
Saved presets convert a set to a target format, bitrate and sample rate in one click, ready for a repeated workflow.
Online and free, with no account and no upload. Re-encode a sound file in the browser, entirely on the device.