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Audio converter · Free · No upload

Convert audio without losing a bit. Nothing gets uploaded.

fkAudio converts music, recordings and the sound of videos to FLAC, WAV, AIFF or MP3 right in your browser. Lossless conversions keep every sample identical to the source, the sample rate is never changed behind your back, and lowering the bit depth is dithered. Trim a clip, keep the tags and cover art, and download one file or a ZIP. Your files stay on your device. No account, no watermark.

How it works

  • FLAC · WAV · AIFF · MP3
  • Video to MP3
  • Up to 24-bit / 192 kHz
  • No upload
Concerto_in_A.flacFLAC · 24-bit · 96 kHz · stereo · 4:12 Lossless ✓ Bit-perfect: every sample is identical. 28.4 MB → 21.0 MB Download CONVERT TO FLACWAV AIFFMP3 BIT DEPTHSame as source SAMPLE RATEKept at 96 kHz Convert

What fkAudio can do

  • Lossless means identical

    Converting between FLAC, WAV and AIFF keeps every sample exactly as it was. We check this in testing by decoding the results with a reference tool and comparing sample by sample.

  • Honest about the source

    See the real format, bit depth and sample rate of every file. If a 24-bit file only uses 16 bits, fkAudio says so, and if the source is lossy it tells you a lossless copy will not sound better.

  • Careful bit-depth changes

    Going down to 16-bit is dithered (TPDF) unless the extra bits are empty, in which case the result is exact. Going up only adds zeros. The sample rate is never changed, except for MP3, which cannot hold 88.2 kHz and above.

  • Sound from videos

    Open an MP4, MOV, MKV or WebM video and save its soundtrack as FLAC, WAV, AIFF or MP3.

  • Trim, tags and batches

    Cut the start and end to the exact sample, keep title, artist and cover art, and convert up to 50 files at once, saved as a ZIP.

  • Private by design

    Your files are decoded and encoded on your device and never uploaded. Conversions run in the browser, so they also work offline once the page has loaded.

How to use fkAudio in 5 steps

  1. Choose files

    Press “Choose audio files”, then select music, recordings or videos from your device, or drop them onto the page.

  2. Pick the format

    FLAC is lossless and about half the size of WAV. WAV and AIFF are uncompressed. MP3 is small and plays everywhere.

  3. Check what will happen

    Each file shows its source details and a plain note about what the conversion will do, such as “bit-perfect” or “lowered to 16-bit with dither”.

  4. Trim if you like

    Open “Trim” on a file and type a start and end time.

  5. Convert and download

    Press Convert, then download each file or all of them as a ZIP.

What people use it for

  • Archive your music losslessly

    Turn WAV or AIFF rips into FLAC to save about half the space, with identical sound.

  • Video to MP3

    Save the soundtrack of a video you made or own as an MP3 for your phone or car.

  • Prepare files for a player or editor

    Make a 16-bit WAV for a device that needs it, or an AIFF for Apple software.

Your files stay on your device

fkAudio reads, decodes and encodes your audio with your own browser. The files are not uploaded to our servers, and we never see them. It only works with files you choose from your device, so please use it for audio you have the right to convert.

These pages use anonymous analytics (Google Analytics) for page views and feature use; file names and contents are never part of that data. Read more about privacy.

Open-source licences

FK WebApp is built with open-source software. These parts ship with the apps, unmodified, and are covered by their own licences.

LAME 3.100 — MP3 encoder in fkAudio (GNU LGPL)

fkAudio makes MP3 files with LAME, compiled to WebAssembly, unmodified. LAME is licensed under the GNU Library General Public License. It is kept as its own file, separate from our code, so you can replace it with a build of your own: the encoder file. The exact LAME source we used is lame-3.100.tar.gz (SHA-256 ddfe36cab873794038ae2c1210557ad34857a4b6bdc515785d1da9e175b1da1e), with the WebAssembly bridge code and the build steps next to it. Licence texts: COPYING and LICENSE. LAME is the work of the LAME project, lame.sourceforge.io. If you cannot reach these files, write to us and we will send you the source.

libFLAC — FLAC encoder in fkAudio (BSD-style)

Copyright © 2000–2009 Josh Coalson and © 2011–2025 Xiph.Org Foundation. libFLAC is redistributed, unmodified and compiled to WebAssembly, under the Xiph.Org BSD-style licence: read the licence. Source: github.com/xiph/flac.

Mediabunny 1.65.2 — media engine in fkAudio, fkCut and fkClip (MPL-2.0)

Unmodified build of Mediabunny and of its FLAC and MP3 encoder wrappers, licensed under the Mozilla Public License 2.0 (licence text). Source: github.com/Vanilagy/mediabunny.

Browser support

Google Chrome (desktop and Android)Tested
Microsoft Edge, Firefox and SafariExpected to work (standard web features only), not yet tested. Opening FLAC, MP3, AAC and Opus depends on the browser’s own decoders

Good to know

  • It works only with files on your device. There is no option to paste a YouTube, Facebook or other web link, and there will not be one.
  • MP3 is made at a constant bitrate from 128 to 320 kbps. Variable-bitrate MP3 is not available. MP3 holds mono or stereo only.
  • The sample rate is kept as it is for FLAC, WAV and AIFF. MP3 cannot hold 88.2, 96, 176.4 or 192 kHz, so those files are converted to 44.1 or 48 kHz for the MP3 only, and the page tells you.
  • FLAC supports the standard rates from 8 to 192 kHz at 16 or 24 bit, with the encoder’s usual compression level. DSD, ALAC, AAC and Opus output are not available.
  • AIFF files carry no tags in fkAudio, and compressed AIFF-C files cannot be opened.
  • A lossy source stays lossy. A FLAC or WAV made from an MP3 is bigger but does not sound better.
  • Very large conversions use a lot of memory. Files that would produce more than about 1.8 GB are refused, so trim them or choose FLAC.
  • fkAudio is an early release, and features may be added or changed.

Frequently asked questions

Is fkAudio free? Do I need to sign up?

It is free, with no sign-up, no login and no watermark. Open the page, press “Choose audio files” and convert.

Are my files uploaded to a server?

No. The conversion happens inside your browser. Your files stay on your device.

How do I convert a video to MP3?

Choose the video file, set “Convert to” to MP3, pick a bitrate such as 192 or 320 kbps, and press Convert. fkAudio saves the soundtrack as an MP3.

Does converting WAV to FLAC change the sound?

No. FLAC is lossless: decoding the FLAC gives back exactly the same samples as the WAV. fkAudio keeps the sample rate and bit depth the same unless you choose otherwise.

Will converting an MP3 to FLAC make it sound better?

No. The information lost when the MP3 was made cannot be brought back. A FLAC made from an MP3 is larger but sounds the same as the MP3, so keep your original lossless files if you have them.

What is dither, and why is it used?

When 24-bit audio is reduced to 16-bit, the rounding creates small distortions. Dither adds a tiny amount of noise that turns them into a steady hiss far below hearing level. fkAudio skips dither when the file only uses 16 bits, because then no rounding happens.

Why is my 96 kHz file shown at 48 kHz in the MP3?

MP3 cannot hold sample rates above 48 kHz, so for MP3 the audio is converted with a high-quality filter. FLAC, WAV and AIFF keep the original rate.

Can I convert a YouTube or Facebook link?

No. fkAudio only converts files you choose from your device, and it never downloads anything from the web. Please convert only audio and video you own or have permission to use.

Which formats can it open?

Whatever your browser can decode, which in Chrome includes FLAC, WAV, AIFF, MP3, AAC / M4A, Ogg Vorbis and Opus, and the sound of MP4, MOV, MKV and WebM videos.

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