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ASF to FLAC converter

Convert ASF to FLAC in your browser. No upload and no account: the file never leaves your device, so the only size limit is your device’s memory.

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Other ways to convert ASF

Convert other formats to FLAC

Read more about the ASF format and the FLAC format, or see every video tool and all video conversions.

Should you convert ASF to FLAC?

Yes, when you only need the sound: a song from a music video, the audio of a lecture, or a voice recording to transcribe. The picture is left out and the soundtrack is saved as FLAC.

ASF is Microsoft’s streaming container, found on old CCTV recorders and Windows Media streams; FLAC is lossless audio at roughly half the size of WAV. Use FLAC to archive music and recordings you may want to convert again later.

ASF and FLAC compared
Property ASF FLAC
What it is Microsoft’s streaming container, found on old CCTV recorders and Windows Media streams Lossless audio at roughly half the size of WAV
Audio inside Windows Media or MPEG-4 video with WMA audio lossless, 16 or 24-bit
Plays on Windows Media Player and VLC Most modern players, Android and recent iPhones; some car stereos and older apps don’t
Best for Old Windows Media streams and security camera exports Archiving music and recordings without losing anything

How to convert ASF to FLAC

  1. 01

    Add your ASF

    Drop your ASF video onto the box, or click to choose it. It is read from your disk and stays there.

  2. 02

    Check the settings

    The output is already set to FLAC. Change the bitrate if you want to; the defaults suit most files.

  3. 03

    Save the FLAC

    Press convert and save the FLAC. Several files come back together as a ZIP.

What changes when ASF becomes FLAC

FLAC is lossless, the soundtrack usually isn’t

The audio inside an ASF is almost always compressed already, usually as WMA. FLAC preserves it exactly but makes a much larger file without sounding better. Choose it for editing software; choose MP3 or M4A for listening.

Video files without sound

Screen recordings and some exported clips have no audio track at all. The file is checked as soon as you add it, and you’ll be told before converting if there’s nothing to extract.

This page is put together from our notes on each format, choosing only what is true of ASF and FLAC, so every pairing states the same facts the same way. How these pages are made.

Why it doesn’t upload

Uploading a whole video to keep only its sound wastes time and data, and hands over the footage too. The audio track is read and saved right here, and the file never leaves your device.

How to check for yourself

Worth knowing

  • About the ASF. CCTV systems often export ASF with timestamps that confuse players, so a recording seems to jump; re-encoding fixes the timing.
  • About the FLAC. FLAC made from an MP3 is lossless only in name: it perfectly preserves an already lossy recording, at five times the size.
  • AVI, WMV, FLV and other older formats use the FFmpeg engine, a one-time 31 MB download.

Questions

Does extracting FLAC from an ASF lose quality?

No. FLAC stores the soundtrack exactly as decoded, although it can’t improve on the compression already in the video.

Can I get the audio from only part of the video?

Yes. Set a start and end time before converting, and only that section is saved as FLAC.

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