How to convert audio online in 3 steps
- 01
Open your audio
Open file, drag one or more files into the drop zone, or click Try a demo. Add as many files as you want to convert together. Accepted inputs include MP3, WAV, FLAC, OGG, Opus, M4A, AAC, AIFF, WMA, WebM, and AMR, plus audio tracks from video files.
- 02
Choose your output settings
Pick an output format from the output format select, then set bitrate for lossy formats, sample rate (keep the source, or 22.05, 44.1, 48, or 96 kHz), and channels (keep, mono, or stereo).
- 03
Render and download
Click Render preview to convert with the FFmpeg (WebAssembly) engine, use A/B to check Original/Processed where useful, then Download audio for a single file or grab a ZIP when you queued a batch.
What you can do with this audio converter
- Convert audio files to MP3, WAV, FLAC, OGG, Opus, M4A (AAC), AAC, or AIFF from one screen, with no separate app for each format pair.
- Batch convert: queue many files, run them through in one pass, and download every result together as a single ZIP.
- Set bitrate for lossy output, choose a sample rate (keep source or 22.05, 44.1, 48, 96 kHz), and pick channels (keep, mono, or stereo).
- Reads more input formats than a browser can decode on its own, including WMA, WebM, and AMR, plus the audio track inside common video files.
- Converts your original file directly through FFmpeg (WebAssembly) rather than routing it through the browser's audio decoder first.
- Keeps existing tags, such as title and artist, wherever the destination container supports them, so you are not stuck re-tagging every file.
- Runs entirely on your device. Files are never uploaded, and there is no account, watermark, or payment.
- After conversion, meters show sample peak, integrated loudness (LUFS), and true peak (dBTP) so you can confirm the result before you download.
What does this audio converter do?
Audio Lab's audio converter online changes audio files from one format to another, entirely on your device. It runs the FFmpeg (WebAssembly) engine in your browser, the same conversion technology used by a lot of desktop software, without installing anything or sending your files anywhere. Open a file, pick an output format, and download the result.
Most browser-based converters decode your file through the Web Audio API first, then re-encode it, which can strip container-level tags and adds an unnecessary decode-and-render pass. This tool converts the original file directly with FFmpeg instead, so metadata such as title and artist carries over wherever the destination format supports it, and there is one less place for audio to be re-processed unnecessarily.
Which audio format should you convert to?
The right format depends on what you are doing with the file next. Lossy formats trade some audio detail for much smaller file sizes and are the right default for sharing and playback. Lossless formats keep every bit of the original signal, at the cost of a bigger file, and are better for editing or long-term archiving.
| Format | Type | Typical use | Compatibility |
|---|---|---|---|
| MP3 | Lossy | Sharing, streaming, everyday playback | Plays on virtually everything: phones, cars, browsers |
| WAV | Lossless (uncompressed) | Editing and archiving master copies | Wide desktop support; large file sizes |
| FLAC | Lossless (compressed) | Archiving with smaller files than WAV | Most modern players and Android; iOS support varies by app |
| OGG (Vorbis) | Lossy | Open-source projects, games, web audio | Strong browser and Android support, less common on iOS |
| Opus | Lossy | Voice, calls, low-bitrate streaming | Very efficient at low bitrates; player support is growing but not universal |
| M4A / AAC | Lossy | Apple devices, podcasts | Native on iOS and macOS, well supported elsewhere |
| AIFF | Lossless (uncompressed) | Mac-native audio production | Best supported on Apple platforms |
Bitrate, sample rate, and channels: what to actually pick
For lossy formats, bitrate is the main quality-versus-size dial: 128 kbps is listenable for spoken word, 192 kbps is a reasonable middle ground, and 256 to 320 kbps is a safer choice for music you care about. There is no bitrate setting for lossless formats such as WAV, FLAC, or AIFF, because they do not throw away data in the first place.
Sample rate and channels are worth touching only when you have a reason to. Keeping the source sample rate is right almost all the time; converting a 48 kHz file to 96 kHz does not add detail that was not recorded, it just makes the file bigger. Switching channels from stereo to mono can meaningfully shrink a voice memo or podcast file where a stereo image was never doing much work.
Converting lossy audio to a lossless format will not restore quality
This is worth saying plainly: converting an MP3 to WAV or FLAC does not bring back the detail that was discarded when the MP3 was first encoded. You will get a larger file in a lossless container, but the audio data inside it is exactly as lossy as it was before. The only way to get a genuinely lossless file is to start from a lossless or uncompressed source.
The reverse direction is predictable, too: converting between two lossless formats, say WAV to FLAC, is effectively exact, since FLAC is a compressed but fully reversible encoding of the same samples. If you care about long-term quality, convert from the highest-quality source file you have, not from a copy that has already been through a lossy encoder.
Batch converting many files at once
To convert audio files in bulk, add every file you need to the queue, choose one output format and settings, and run the conversion once. When it finishes, download everything together as a ZIP instead of exporting one file at a time. This is the fastest way to move a folder of podcast episodes, a batch of voice memos, or an old collection of a less common format like WMA into something more universally playable, such as MP3 or M4A to MP3.
Once a file is converted, you can also use Continue in another tool to send it straight into the metadata editor, the trimmer, or another Audio Lab tool without exporting it and uploading it again.
Is converting audio online actually private and free?
Yes. Conversion runs locally in your browser using FFmpeg (WebAssembly); your audio files are never uploaded to a server. There is no account, no sign-up, and no watermark on the output. The compressed-format encoder is roughly a 31 MB one-time download that your browser caches, so the first conversion is a little slower while it fetches and the rest are faster.
It works on mobile browsers too, though very large files or long batch queues can run slowly or hit memory limits on a phone, more so than on a desktop. The per-file limit is 150 MB, and actual results depend on your device's available memory.
Tips for better conversions
- Convert from your original or highest-quality file whenever you have a choice. Converting a copy that was already compressed just locks in whatever quality it lost.
- Leave sample rate on keep source unless you have a specific downstream requirement; a higher sample rate does not add detail that was not in the original recording.
- Use 256 to 320 kbps MP3 for music and 128 to 160 kbps for spoken word such as podcasts or voice memos, where the extra bitrate buys you little.
- Switch to mono for single-voice recordings to cut file size roughly in half without a noticeable quality loss.
- When you batch convert audio files, double check the output format and bitrate before you run the whole queue, since those settings apply to every file in the batch.
- If a destination format drops some of your tags, fix them afterward in the audio metadata editor rather than re-converting.
- Choose FLAC over WAV when you want a lossless archive copy that takes up noticeably less disk space.
Frequently asked questions
Is this audio converter really free?
Yes. The audio converter online is free to use, with no sign-up, no account, and no watermark added to your files. You only pay with a one-time download of the conversion engine on first use, which your browser then caches.
Are my files uploaded to a server?
No. Conversion runs on your device using FFmpeg (WebAssembly). Your audio never leaves your browser during the process, which is also why it keeps working without an internet connection once the engine has loaded.
What audio formats can I convert?
You can convert to MP3, WAV, FLAC, OGG, Opus, M4A (AAC), AAC, or AIFF. Accepted inputs are broader, including MP3, WAV, FLAC, OGG, Opus, M4A, AAC, AIFF, WMA, WebM, and AMR, plus audio extracted from video files.
Is there a file size limit?
Each file can be up to 150 MB. Your device's available memory can lower that in practice, particularly on phones or when batch converting many large files at once.
Will converting reduce my audio quality?
It depends on the direction. Lossless to lossless (WAV to FLAC, for example) is effectively exact. Lossless to lossy discards some data. Lossy to lossless does not lose more, but it also cannot restore whatever detail the original lossy encode already threw away.
Can I convert multiple files at once?
Yes. Add several files to the queue, set your output format and settings once, run Render preview, and download every converted file together as a ZIP instead of one at a time.
Will my metadata tags carry over after converting?
Tags such as title and artist are kept wherever the destination container supports them. If a format drops fields you need, you can add them back afterward with the audio metadata editor.
Does this MP3 WAV FLAC converter work on mobile, like an iPhone or Android phone?
Yes, it runs in mobile browsers. Large files and long batch queues can be slower and are more likely to hit memory limits on a phone than on a desktop, so expect variable performance depending on the device.
What bitrate should I use for MP3 conversion?
For music, 256 to 320 kbps is a safe choice. For spoken word such as podcasts or voice memos, 128 to 160 kbps is usually plenty and keeps files noticeably smaller.
Do I need to install any software?
No. Everything runs in your browser. The compressed-format engine is a roughly 31 MB one-time download that your browser caches after the first conversion, so later conversions start faster.
What is the difference between this tool and video-to-audio?
Audio-converter changes existing audio files between formats. Extract audio from video is for pulling the audio track out of a video file, with audio-track selection and an original, no re-encode option, and it is not a URL or YouTube downloader.
Can I edit tags or add cover art after converting?
Yes. Send the converted file to the audio metadata editor to edit title, artist, album, and other fields, or to add cover art to FLAC if your output is a FLAC file.
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