Audio Converter – Convert WAV, FLAC, M4A and MP3 Online

Convert between WAV, FLAC, AAC, OGG, and MP3 with title/artist/cover-art metadata carried over.

Given a batch of files, the converter first checks whether it can switch containers without touching a single audio sample — a genuinely lossless operation available only for specific source/target pairs — and only falls back to a full decode-and-re-encode pass when that isn't possible. Five output formats are offered, tags carry over wherever the target format has a slot for them, and a single result downloads as-is while several arrive together as one zip.

How to convert WAV to MP3 (or any format)

Drop one or more audio files onto the converter, or click the drop area to pick them; each file is queued and analysed in the page.
Choose the output format — WAV, FLAC, AAC (M4A), Ogg Opus or MP3 — and its setting: MP3 bitrate from 128 to 320 kbps, FLAC level 0 to 8, or Opus quality from 48 to 256 kbps.
Optionally switch on custom naming and type a template with the {name}, {n} and {ext} tokens; the output filenames preview live underneath.
Click convert, check whether each file was remuxed or re-encoded, then download: one result saves as the file itself, several come as a single ZIP.

The remux-first path, and where it actually applies

Three source containers are eligible for container-only remuxing: AAC audio inside an M4A/MP4 file, MP3 (its ID3v2/ID3v1 wrapper is stripped and the raw frame data underneath is repacked as-is), and Opus packed inside Ogg. Remuxing only happens when the target format uses the same codec as the source — M4A to AAC (M4A), MP3 to MP3, Ogg Opus to Ogg Opus — and then converting is just repackaging bytes into a new container plus writing fresh tags, so no quality is lost because none was ever regenerated. Every other pairing, MP3 to AAC included, decodes and re-encodes.

WAV, FLAC and Vorbis-in-Ogg sources never attempt this path; they always decode fully and re-encode. This tool ships no Vorbis decoder of its own, so a Vorbis-in-Ogg source is handed to the browser's built-in audio decoder, and where that decoder can't read Vorbis the file surfaces as a conversion error rather than a silent wrong result.

Choosing an output format and quality

WAV — uncompressed, always lossless, no quality setting to choose.
FLAC — lossless with an adjustable compression level from 0 to 8 (default 5); higher values shrink the file further without changing the decoded audio at all.
MP3 — lossy, with a bitrate selector from 128 to 320 kbps.
AAC (M4A) — lossy, encoded at a fixed 128 kbps through the browser's own audio encoder.
Ogg Opus — lossy, with a quality selector from 48 to 256 kbps aimed at speech and streaming use.

Formats the audio converter accepts

WAV — read in full every time and never eligible for the remux shortcut, even when the target is WAV again.
MP3 — repackaged without re-encoding when you convert to MP3; any other target decodes it first.
M4A and AAC — AAC audio inside an M4A can be copied into a new M4A without touching the samples; raw .aac files, and M4As headed for any other target, are decoded.
FLAC — decoded by a bundled WebAssembly FLAC decoder, so browser FLAC support doesn't matter.
Ogg Opus — remuxed when the target is Ogg Opus, otherwise decoded through WebCodecs where the browser provides it.
Ogg Vorbis — the exception: it relies entirely on your browser's own decoder, and Vorbis is never offered as an output.

What happens to your tags

Title, artist, album, track number, year and genre are readable from every source format this tool accepts and writable into every output format's own tagging scheme. Cover art is the one exception on the output side: WAV's RIFF INFO convention has no standard slot for embedded artwork, so a source file's cover art is silently absent on WAV output. Before you download, the tool discloses exactly which fields — if any — could not be carried over for your chosen target, rather than dropping them without telling you.

Batch naming

By default, every output file keeps its source name with only the extension swapped for the new format. A custom naming template can be supplied instead, previewed live against every queued file before conversion runs, with automatic numeric suffixes added if two files would otherwise collide on the same output name.

Converting without an upload queue

Each file is read through the browser's File API, remuxed or decoded and re-encoded inside the tab, and the ZIP is assembled locally with JSZip before the download starts. You never wait on an upload progress bar, and there is no server-side copy for a 'deleted after a few hours' promise to cover, because your audio was never sent in the first place.

Where this tool falls short

There is no Vorbis output option at all — the five formats listed above are the complete set this tool can produce, because no separable, permissively licensed Vorbis encoder was available to build against. Remuxing never helps across codecs either: MP3 to AAC, or AAC to MP3, always takes the slower decode-and-re-encode path. And any conversion that does need a full decode pass is, unavoidably, a lossy re-encode whenever the target format is itself lossy — converting MP3 to AAC never recovers quality the MP3 encode already threw away.

Format conversion is free for 15 output files each day; Pro converts without a daily number.

Questions people ask about Audio Converter

How do I convert WAV to MP3?: Drop the WAV files in, set the output to MP3, pick a bitrate between 128 and 320 kbps, and convert. WAV sources are always decoded and freshly encoded, and any RIFF INFO title, artist or album tags are rewritten as ID3 tags in the MP3.
Are my files uploaded to a server?: No. Reading, remuxing, decoding, encoding and zipping all happen in the browser tab on your own device, so your audio never crosses the network. Even the daily free-tier counter is stored in your browser rather than on a server.
Can I convert several files at once?: Yes. Add as many files as you like and they all convert to the one output format you pick, downloading together as a ZIP. On the free tier a batch counts against the 15 files per day, and a batch larger than your remaining allowance is refused before any file converts.
Can I convert a video to MP3?: Not with this converter: its picker and drop zone only accept audio files, so MP4, MOV and WebM videos are ignored. Use the Audio Extractor instead, which pulls the soundtrack out of a video and can save it directly as MP3.
Why did my MP3-to-MP3 conversion finish almost instantly?: MP3 is one of the three source containers eligible for the remux-first path: its ID3 wrapper is stripped and the raw frame bytes are repacked with fresh tags, with no decode or re-encode step at all. That only happens when the target uses the same codec, so MP3 to AAC is always a full re-encode — each finished file is labelled remuxed or re-encoded.
Will converting to WAV lose my album art?: Yes, specifically for WAV. Every other output format this converter supports — FLAC, AAC, Ogg Opus and MP3 — has a slot for embedded cover art, but WAV's tagging convention does not, so any cover art present on the source is dropped for that one target and disclosed before you download.
Can I convert a Vorbis-in-Ogg file here?: Only if your browser can decode Vorbis. The converter has no Vorbis decoder of its own, so it hands the file to the browser's built-in audio decoder; when that fails you get a clear conversion error instead of a broken file. Vorbis is never available as an output format.
Does a higher FLAC compression level improve audio quality?: No — FLAC is lossless at every compression level from 0 to 8, so the decoded audio is bit-for-bit identical regardless of which level you pick. The slider only trades encoding time and resulting file size; a higher number takes longer to encode and produces a smaller file, never better-sounding audio.

Related tools on BrakeTools

Audio Extractor — Pull just the audio track out of an MP4, MOV, or WebM video file.
Audio Cutter — Drag in an audio file, select a range on the waveform or by typed start/end seconds, then remove or keep just that portion.
Audio Volume Changer — Make audio louder or quieter, normalize peaks, protect against clipping, add edge fades, and export in five formats without uploading it.
Audio Joiner & Crossfade Mixer — Combine multiple audio tracks in any order, trim each one, blend transitions with an adjustable crossfade, and export locally as MP3, WAV, FLAC, M4A/AAC, or Ogg Opus.

Content reviewed 2026-09-27.