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FLAC Uncompressed [How to Convert? 2023]

Uncompressed FLAC is a file that contains content in Free Lossless Audio Codec format without size reduction. Read about sound quality, F.A.Q., comparison with WAV, uncompressed FLAC settings in the audiophile sound converter software AuI ConverteR 48x44.
April 11, 2023 updated | since October 24, 2017

Author: Yuri Korzunov,
Audiophile Inventory's developer with 25+ year experience in digital signal processing,
author of the articles that make audio easy for beginners

How to convert from/to uncompressed FLAC

To convert audio files from/to uncompressed FLAC:

  1. Open audio converter software AuI ConverteR 48x44:

  2. Click Open files button and select input music file.
  3. In the main window, Format panel (right middle part), select FLAC or another target format, bit depth, and sample rate.
  4. Select output directory
    In the left bottom of the main window, push ... button right Directory output files field.

    It can be an absolute or relative (of the source file) directory.

  5. Click Start button.

    Wait for the conversion to finish. Converted sound files are located in the output directory.

WARNING: DVD-audio/video, Blu-Ray, DVD/BluRay/CD ISO are NOT supported.
For Modula-R version, SACD ISO, DSF, DFF are supported in proper configurations.
For ISO tracks, DSF, DFF longer than 3 minutes, FREE edition mutes 2-second silence in the output middle and has other restrictions


Watch and share: How to split CUE FLAC


Uncompressed FLAC vs WAV


There is the hypothesis, that uncompressing process of Free Lossless Audio Codec causes additional noise. Still, there isn't serious research on this subject.
To avoid uncompressing, WAV or uncompressed FLAC format may be used.

Watch and share: WAV and FLAC binary content comparison

The hypothesis try to explain the sound difference

When the compressed file format is unpacked, the central processor unit of a computer (or processor of a music device) has a higher load. Therefore, in the system, processor noise is higher. And, computer's electrical noise degrades sound. It happens despite binary-identical data feeds digital/audio converter (DAC) for both compressed FLAC and WAV.

How to check it

It may be checked via spectral comparison of the analog output of DAC. Measurement is applied during playback for each of these alternative formats.

However, some details should be accounted for to avoid wrong results. The author thinks, that it's a matter of sound system implementation rather. And for the exact answer to the question, serious research is required for many systems and devices.

However, WAV has displaying metadata (music track information and artwork(s)) issues for some players. Because WAV contains no standard meta tag implementation and uses a custom data block with ID3 format.

FLAC has standard meta tag implementation and must be supported by any player, that is comparable with the format.

Both of these alternative formats have partial compatibility with metadata. Though some issues may happen due to implementation.

WAV vs FLAC format (uncompressed)

  FLAC uncompressed WAV
Sound quality The same to WAV (binary identical sound content) Same to FLAC (binary identical sound content)
Size Depend on metadata and frame size and about packed PCM sound data Depend on metadata and about packed PCM sound data
Metadata Standard FLAC's implementation like id3 or LIST chunks (data blocks). May have compatibility and display issues with some software and firmware


FLAC uncompressed vs compressed

For sound quality no difference between compressed and uncompressed FLAC. Because any lossless file contains identical unpacked binary content for single original audio stuff.

There is the hypothesis, that FLAC uncompressing causes additional noise due to higher computational load. But there is no safe evidence.


FLAC compression level settings


  1. At the main window of the software, push Settings button.
  2. At the Settings window, select General tab.
  3. Set compression level with FLAC compressing slider (most left position).
    Free Lossless Audio Codec uncompressed is the most left position.
  4. Push OK button.

Settings: uncompressed FLAC

FLAC uncompressed settings


Size and binary content of FLAC files

FLAC is divided into frames. Frames may be assigned inside a conversion software. So, different conversion utilities may have slightly different Free Lossless Audio Codec uncompressed file sizes.

Also, padding (free space reserve) may cause various file sizes. The reserve is used for faster metadata saving without full file re-writing.

Unpacked binary audio content doesn't depend on converting tool and compression level.



FLAC uncompressed




AuI ConverteR has several price/functionality options that allow saving your budget for the required functionality. You can expand Modula-R abilities later by purchasing new modules. Unlimited-time license, major updates (... 10.x > 11.x > 12.x > ... versions) are paid.

* All prices on this page are in U.S. dollars without V.A.T. and other applicable taxes and fees. The prices are recommended. Information on this page is not a public offer.

FULL-FEATURED version [AuI ConverteR PROduce-RD]

[MINIMUM PRICE] for full functionality of AuI ConverteR, in comparison with Modula-R edition that is including all modules.

FULL-FEATURED version [AuI ConverteR PROduce-RD]
Best Seller


All abilities are included in PROduce-RD version. It allows saving budget, comparing purchasing of the full abilities (all modules) of Modula-R edition. Unlimited-time license, paid major updates (... 10.x > 11.x > 12.x ...).

PCM converter [Modula-R edition]

[MINIMUM PRICE] configuration of WAV, FLAC (compressed/uncompressed), AIFF, ALAC (up to 24 bit / 192 kHz), mp3
audio file converter (PCM formats) [consists of 1 module]

PCM converter [Modula-R edition]
Best Seller


Minimum price configuration to conversion PCM files, including CUE splitter. Don't support CD-audio. May be expanded by purchasing of other modules.

Build custom configurations > Expand functionality > Ask for advice >



Frequently Asked Questions

Is FLAC uncompressed? Is FLAC compressed? Can FLAC be uncompressed? Is FLAC compressed or uncompressed?

FLAC audio content may be losslessly compressed by size or not, according to the user option. Whether compression is there or not, it doesn't impact sound quality.


What compression does FLAC use?

FLAC use file size compression. The compression has several levels. Also, in some applications, FLAC may be uncompressed.


What is FLAC level?

FLAC level may be understood as compression level. It defines the balance between the compression speed of a source file to .flac and the FLAC-file size. Compression level doesn't impact sound quality.


What is the best FLAC compression level?
What level of FLAC compression is best?
What FLAC level is best?

FLAC compression levels define the ratio between FLAC-file size and time of compression to the file.

There is no big difference between compression levels by size. Thus, level 5 (average between the minimum and maximum) may be recommended as optimal (the best).


Is FLAC better than WAV?

For sound quality no difference. The author supposes, FLAC has wider metadata compatibility with a device and software, than WAV. And FLAC has a lesser file size. However, sample rate and bit depth of FLAC is limited 32 bit / 384 kHz. Read more...


Is FLAC better than AIFF?

Both FLAC and AIFF are the same for audio quality. Looks like, FLAC has metadata compatibility for a wider device and software ranges, comparing AIFF. FLAC advantage is the lesser size of computer files. FLAC has limitations in sample rate and bit depth: 32 bit and 384 kHz. Read more...



Does FLAC lose quality?

No. FLAC fully keeps original audio data. FLAC is a true-lossless sound format.


Is uncompressed audio better?

If compression is lossless, it does not matter the uncompressed or compressed audio format.

Lossy compression has losses (distortions), comparing losslessly compressed or uncompressed audio.


Is FLAC lossy or lossless? Is FLAC true lossless?

FLAC is true lossless always independent of the level of compression, including the uncompressed one. Read more and watch video...


Is FLAC really lossless?

Yes. Any FLAC codec is always lossless. However, FLAC may be used as a container for lossy audio data. Read more and watch video...


Does FLAC compression level affect quality?

No. FLAC keeps lossless for any compression level, including the uncompressed option. Read more and watch video...


Is FLAC 16 or 24 bit?

FLAC supports bit depths 16-, 24-, 32-bit by user option and audio software abilities.


What is the compression rate of FLAC?

The compression rate of FLAC is [compressed FLAC size, bytes] / [source uncompressed file size, bytes] ratio.


How much does FLAC compression?

To pre-estimate FLAC compression, you can use 0.6 of uncompressed source size.

As example, when converting CD to FLAC, we can expect 420 MBytes for 700 MBytes of a CD-audio.


Is FLAC better than 320 Kbps?

FLAC is a lossless format. At the moment of the answer writing, available formats with bitstream 320 Kbps for 44.1 kHz / 16 bit (in instance: mp3, AAC) are lossy.

So, technically, FLAC is better in sound quality. But, lossy formats allow saving free disk space.



Read more