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accurate audio file converter software for
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FLAC, WAV, AIFF, ALAC, SACD ISO, DSF, DFF, mp3, m4a, CD...
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Audio Basis - articles about audio
Read the definitive guide:
• what is the best [highest quality] audio format (codec):
WAV, FLAC, mp3, AIFF, m4a, AAC, ALAC, PCM, DSD, DSF, DFF, SACD;
• lossy and lossless compressed sound files,
• PCM and DSD formats;
• audio codecs for Android, iOS, Mac, Windows, Linux,
• Frequently Asked Questions,
• look at the infographic how to choose the best audio file format for you.
- DSD converter software list
- Frequently Asked Questions
- What is highest quality audio format?
- Overview of audio files
- Audio formats (codecs)
- PCM formats
- Lossless audio formats
- Lossy compressed
- DSD formats
- Bluetooth audio codecs
- PCM formats
- What is an audio codec
- Audio formats for iTunes
Read this F.A.Q. about audio file formats (codecs), and read details below.
Popular audio file formats (file extensions):
- WAV | WAV RF64 | WAV BWF (.wav)
- FLAC (.flac)
- AIFF (.aiff, .aif)
- mp3/MPEG (.mp3)
- AAC (.m4a)
- ALAC (.m4a)
- WavPack (.wv)
- DSD (.dsf, .dff)
- DSD DoP (.wav, .flac)
- MQA (.flac)
Download free music files...
The best audio codec is defined according to your aims: sound quality and data compression ability.
Lossless formats are the best for sound quality.
Best sound quality is provided by audio formats without losses of information. They are so-called "lossless" formats.
There are several most common audio codecs for different applications:
|mp3||Music files, movie|
|AAC||Music files, movie, bluetooth|
What is the best audio format for sound quality? Which is the best quality audio format? What is the highest quality codec?
The best sound-quality audio formats are lossless ones. These formats keep source musical data without losses.
If you uses hi-fi equipment, these formats are most recommended. For mobile applications, AAC format in high bitrates (256 kbps nad more) may be recommended.
Read more about audio formats with maximal audio quality...
Sound quality has 2 definitions:
- [objective] distortion level;
- [subjective] how it sounds - nice or not.
At the first sight, the subjective definition may not be estimated. But, it wasn't.
Both definitions are united by psychoacoustics.
It is a matter of audio equipment and played back recording. High resolution gives the potential abilities to achieve a better result for designers of audio equipment and software,
Music requires maximum abilities, that can provide audio formats (codecs).
But, for portable audio players and mobile phones, high bitrates (256 kbps and higher) are recommended for stereo recording, which is compressed by lossy codecs (mp3, AAC).
According to Google statistics (April 2019), mp3 is the most popular format (among mp3, WAV, FLAC, ALAC, m4a, AAC). Second place - m4a, WAV, AAC. ALAC and FLAC are in the 3-rd position. m4a is a container for AAC and ALAC.
To achieve maximal sound quality use lossless files.
The best audio-file formats for editing are lossless non-compressed PCM files (WAV, AIFF).
Lossless codecs (FLAC, WAV, AIFF) are preferable here. It does not matter whether compressed or not.
The developer of mp3 recommends to using AAC instead.
A lossless audio format saves audio data in bit-perfectl condition. Read more...
FLAC format has better compatibility by metadata with different units than WAV.
DSD files (.dsf, .dff, .iso [SACD ISO]) to native playback require DSD DAC. Theoretically, the DAC can achieve full performance of DSD files. Practically, it doesn't mean that DSD sounds better than PCM.
Thus, you can choose the best lossless format referring to your equipment.
Lossless is the same for any file type. All these file types provide the same sound quality. I.e., as example, WAV and FLAC sound the same quality.
However, "lossless" term may have the different meanings. And, MQA, in instance, is not "lossless" for 24-bit resolution in "bit-perfect" meaning. Despite the format provides high quality.
Read what is "lossless" in common sense...
Read about MQA...
WAV audio format almost is not limited in supported audio resolution. Output of high resolutions codec consumes big hard disk space. And for WAV files with sizes 4 GB and larger, WAV/RF64 format was applied.
FLAC has no size limitation, but its maximal resolution is 384 kHz / 32-bit in some implementations.
DSD files are separate branch, that can provide lesser distortions than PCM ones (WAV, FLAC, AIFF, etc.) in some hardware implementations. In other cases, PCM files may sound better than DSD ones. Read more...
FLAC format is one of lossless audio formats. It has the same sound quality as other true lossless audio formats.
Sound quality may be defined by sampling rate. Higher sampling rate gives potential ability to get higher quality.
FLAC supports up to 384 kHz. WAV supports higher sampling rates.
No. FLAC is capable to save CD content if full sound quality.
Free Lossless Audio Codec provides lossless audio. Advanced Audio Coding provides lossy data compression. From a technical point of view, FLAC gives better sound quality than AAC. But, the last one at high bitrates 250+ kbps may be very same lossless.
FLAC provide data size compressing of audio information without losses. Thus it provide better sound quality than mp3.
Stereo mp3 with high bitrates (256 kbps and higher) almost may not be distinguished with FLAC by sound quality.
But mp3 have limited resolution audio (up to 48 kHz / 16 bit) that might not provide advantages of high resolution audio.
Standard WAV file size is limited 4 Gbytes. It solved via WAV RF64 format using. But this format have compatibility limitations with software and devices.
Practically, at high bitrates, lossy files are very same lossless at the sane sampling rates and bit depths.
High AAC bitrates may be undistinguished with original WAV.
ALAC and WAV are providing the identical sound quality. At high bitrates (250 kbps and above), it's very difficult to distinguish AAC and WAV.
Despite AAC is desined as lossy codec, it provides high quality at high bitrates. In instance, above 250 kbit per second.
AAC is lossy codec. Technically, lossless ones is better choice. However, AAC save bitrate better than any lossless one (at moment of the aswer writing). And high-bitrate AAC is good for hi-fi sound quality.
So, AAC may be recommended for mobile applications and streaming.
Yes. Stereo mp3 or AAC 320 kbps is very similar to FLAC and WAV in the same audio resolution (sample rate and bit depth). General recommendation is 256 kbps or higher for stereo mp3 or AAC.
If you use AAC in higher resolutions or multichannel audio, higher bitrate may be desirable.
General advice: try different bitrates for same original recording(s). If you hear no difference with the original recording, use this bitrate.
AAC designers state, that AAC better accommodated psychoacoustical factors, than mp3. So AAC is more recommended.
Actually, you can compress original lossless file to mp3 and AAC at different bitrates (256 kbps and above). Compare these files with the original by your ears.
If you don't hear difference, use mp3 or AAC, according compatibility of your audio player or software.
If you prefer high resolution audio or multichannel recordings, you can use AAC instead mp3. Because last one is limited 48 kHz / 16 bit stereo.
At high bitrates, probability listening of difference is low. Also, listened audio system is matter.
AAC is newer format. And, it's promissed as a good format for high-resolution recordings.
WAV is lossless format and keep all auidio information. So it causes lesser distortions than lossy mp3. However, high mp3 bitrates (256 kbps and above) are very close to lossless source file (low distortions) and keep space, that is important for mobile applications.
However, mp3 don't support sampling rates above 48 kHz and can't use sound quality abilities of hi-res audio devices.
Technically for Bluetooth[*], provided bitrates are:
- AAC - up to 250 kbps,
- AptX - up to 352 kbps,
- AptX HD - up to 576 kbps.
All are lossy formats.
AptX gives better potential due to higher bitrate. As default, we can prefer an audio format with higher bitrate. But, only you can estimate real advantages in your personal case.
aptX codec for wireless applications has several types:
- aptX [latency 170 ... 270 ms];
- aptX (HD) [supports 24-bit / 48 kHz with maximum bitrate 567 kbps, latency 170];
- aptX LL [latency up to 40 ms];
- aptX Adaptive [adaptive bitrate 279 ... 420 kbps with low latency 80 ms, backward compatible with aptX and aptX HD];
- aptX Lossless [introduced by Qualcom in 2021, lossless 44.1 kHz (CD-quality audio) / 16 bit or 24-bit / 96kHz lossy].
If you use wireless headphones for music production or games, aptX LL may be recommended due to low latency.
For music listening, aptX (HD) / Adaptive / Lossless may be recommended.
You can get plenty opinions what Bluetooth audio codec is the best. If you have possibility to listen and compare codecs, do it to get personal opinion. Modern wireless codecs are good and their difference is subtle enough.
In common, recommended codecs:
- LC3 [*].
For Bluetooth aptX/aptX(HD) should provide up to 352/576 kbps, respectively. AAC provides up to 256 kbps. Theoretically, higher bitrate may be more able to bring higher sound quality. However, it may be rather matter your mobile phone and headphones. Test it for yourself.
AAC requires more computing resources than SBC or aptX, and, respectively, tend to higher consuming of battery energy [*].
- To maximize sound quality use lossless AIFF and ALAC (*.m4a).
- Convert similar lossless audio files to mp3 and m4a and compare its sound.
- Bitrates 256 kbps and above are recommended.
If internal phone/tablet's DAC is used, lossless PCM formats are preferable.
Some external DACs support DSD.
Lossless multi-channel sound formats (Dolby TrueHD, DTS-HD Master Audio) are recommended for home music systems.
To keep hard disk space DTS support lossy compression.
Also, lossy AC3 may be used.
Lossy compression is recommended to web and portable applications.
If car stereo supports FLAC or WAV files, these files give maximal quality.
In general, it is compressed formats: mp3, m4a, ogg, flac.
Yes. Spotify uses AAC codec for audio streaming.
Audio format is data structure and coding type to store musical information.
Audio coding in simple words
Let's imagine music as a various-size ball sequence.
● ● ●●●
We can accept codes (numbers):
Small ball is number "1".
Middle ball is "2".
Big ball is "3".
Silence is "0".
So, the sequence (music) may be coded as:
Codec is software and/or hardware to code/encode audio format to processing and/or playback on DAC (digital-to-analog converter).
Original stuff (DSD or PCM modulation) from ADC (analog-to-digital converter) is coded to a format with encoder.
Restoring from the format to PCM or DSD modulation to playback at DAC is performed with a decoder.
Codec = encoder + decoder.
Some sound formats are called as "audiophile file formats". They provide higher sound quality, than "non-audiophile" ones.
Sound quality is considered here as distortion level of original music stuff after storing into an audio file.
There are music file formats:
- non-compressed: WAV, FLAC, AIFF, ALAC, DSF, DFF, SACD ISO.
- lossless compressed: FLAC, APE, DTS-HD Master Audio, WavPack, DFF, SACD ISO;
- lossy compressed: mp3, AAC, MQA, DTS, OGG, others.
Compressed mean reduced-by-size audio content. As rule, lossy compression provides size compressing better, than lossless ones, because part of audio information is lost.
The best sound quality audio recording formats are called "lossless". They keep audio quality without any losses (audio data of original and decoded music stuff are binary identical).
Lossless formats are capable to store original musical stuff without altering. I.e. sound quality of any lossless format (compressed or not) is identical. However, the transformation between DSD and PCM lossless audio files is lossy.
The sound quality of playback
Playback sound quality is not the same sound quality of an audio format.
Losses of audio format are only part of playback sound quality.
Playback sound quality includes distortions of:
- recording, mixing, post-production;
- playback software;
- playback hardware.
When we upsample music, it can be played back with another distortion level of playback software and/or hardware.
Upsampling is lossy. But distortion level of playback software and/or hardware may be lesser these values for the original resolution.
So, total playback distortions after lossy upsampling may be better, than without the upsampling.
Resume: the best sound quality music formats are any lossless formats. But conversion between lossless PCM and lossless DSD is lossy. However, the conversion of format or resolution audio can give playback quality advantages (read details).
Music formats are intended for solving different issues:
- maximal sound quality providing;
- saving of hard disk space at a musical device;
- song information (metadata: album artwork, song and album name, performer, etc.) providing;
- maintenance of file compatibility with software and hardware.
Audio format types
- by modulation: DSD and PCM;
- by size compression: compressed and non-compressed:
compressed files by sound quality:
Sound quality does not matter of used operating system (Android, iOS, Windows, Mac, Linux, others) of computer or mobile device. The quality depend on playback system settings rather, including operating system drivers.
* MQA format is lossy, as far as the author know (details).
FLAC in the table means "Free Lossless Audio Codec". *.flac file may be used as a wrapper to other formats (MQA, as for an example).
PCM formats (WAV, FLAC, AIFF, ALAC, APE, MQA, CD-audio) may be compressed (lossless or lossy) or not.
Most popular WAV and AIFF may have metadata compatibility issues with audio software and hardware.
What is the best lossless audio format? By sound quality all lossless formats are identical. But there are compatibility and metadata issues. Read the details below.
"Lossless" means "without losses". It refer to audio file size compression.
Original digital-audio data (song) is compressed by size.
If we uncompress the data, it will be absolutelly identical to the original one.
Example: let's original file contains two stars: **. It's 2 symbols in an audio file.
We can agree: "**" is "1".
So, we can compress audio file by size twice when replace "**" to "1".
Before listening to the file, we replace "1" back to "**".
Both original and played back audio are the exactly same: "**".
So, such file-size compression is "lossless" (don't cause losses).
These music files are most popular among uncompressed lossless formats. Lossy compressed audio data may be stored in the *.wav and *.aiff files though.
Many sonic devices support these formats, but there aremay be issues with metadata displaying at some hardware and software.
AIFF may be recommended as an uncompressed format for iTunes due metadata compatibility.
WAV and AIFF can contain DoP packed DSD audio stream. Such files cannot be played back without special processing or hardware.
In general WAV, AIFF may be used to editing software (faster opening without additional processing), home music library at big size hard disks. For the libraries, Free Lossless Audio Codec is more recommended.
AIFF and WAV have no special limitation by sample rate and bit depth (except header field size). File size for these types is limited: 2 GBytes.
WAV RF64 and SONY's WAV64 formats allow to creating WAVs with size more 2 GBytes.
There is AIFF-C lossless format for CD-audio tracks. Read the details below.
FLAC compressed lossless format reduces file size and keep binary audio content without altering. FLAC has compatibility by metadata with many hardware and software.
FLAC is not compatible with iTunes player.
Like WAV and AIFF, Free Lossless Audio Codec can contain DoP packed DSD music.
It is losslessly compressed audio file format. The format may be recommended as FLAC replacement for iTunes.
Compact disk (CD) contains data in format like WAV 16 bit / 44.1 kHz. Audio data from compact disk may be stored in WAV and other audio files via CD ripper software.
Under Windows at compact disk *.cda files are displayed. But it is index files that contain track time position. *.cda file copying doesn't provide audio stuff extracting. There is need audio ripping software.
Under Mac OSX *.aiff files are displayed at a compact disk. These files may be copied as usual sound files. But these files contain AIFF-C lossless format. It has inverse order of audio bytes, than usual AIFF. AIFF-C may be converted to AIFF without losses.
Read more about CD ripper software >
WMA (Windows Media Audio) has the lossless ability at codec version 9.
WMA to WAV may be converted via wmal2pcm utility.
The utility may be located at "c:\program files\windows media components\tools\wmal2pcm". Additional installing may be required.
About the pack with WMA codec read here...
Also, check the download page Media Feature Pack for N and KN versions of Windows 10...
APE (Monkey's Audio codec) has the lossless compressing ability. Metadata are supported. Official codec builds, known by the author, for Windows only.
Read details here
WavePack is a lossless audio format. Metadata are supported.
Read details here
CAF (Apple Core Audio Format) is file container for lossless audio format (uncompressed PCM or compressed by ALAC codec). Metadata are supported[ref].
Also, see CAF lossy
DVD-A (DVD-audio) support uncompressed PCM audio stream: stereo (16|20|24-bit / up to 192 kHz) or 6-channel surround (up to 24-bit / 96 kHz)[ref].
DVD-V (DVD-video) support uncompressed PCM audio stream stereo (16|20|24-bit / up to 192 kHz) or DTS 5.1-channel surround (up to 24-bit / 96 kHz)[ref].
MQA is an audiophile PCM format. It conveiys lossless high-resolution audio up to 17-bit/96 kHz.
Lossy compressed formats like mp3, aac, ogg and others are intended to save maximal song number into limited hard disk space of musical device (especially mobile phone or portable digital audio player) or computer.
AAC more modern codec than mp3. And AAC developers promise better sound quality, than mp3 (details).
Lossy compressing technologies are balance between audio quality losses and minimal size.
Bitstream characterizes lossy files. The bitstream is bit number of audio information per second. The best bitstream audio quality (kbps / kbit per second) mean minimal file size, but still good sound quality.
As rule lossy files have no metadata compatibility issues.
WAV and AIFF have lossy modifications. But they are not widespread.
What is best audio codec for lossy file? It is unknown exactly, because depending on many factors.
In general, to provide high sound quality of mp3, 256 kbit/s and higher bitrates may be recommended.
Windows Media Audio (WMA) format is one of the popular lossy codecs, that also have lossless abilities in version 9.
ac3, aac, dts formats allow to storing multichannel compressed sound.
- The Effects of MP3 Compression on Perceived Emotional Characteristics in Musical Instruments
- Alexander Benjamin. Music Compression Algorithms and Why You Should Care
- A short study on audio compression
- About AAC format
- AAC audio playback tests (multichannel)
CAF (Apple Core Audio Format) is file container for lossy audio formats (compressed by AAC, mp3 and other codecs). Metadata are supported[ref].
Also, see CAF lossless
MQA is a PCM format. Looks like, it provides better size compression than FLAC (see here). But MQA has some losses above above 17-bit/96 kHz resolution, as far as the author know (see details). Of course, MQA losses are minimal to provide high sound quality.
MQA may be played back without decoding with lesser (than MQA's maximal) sound quality. It provides its compatibility with non-MQA software and hardware.
Read more about MQA.
DVD-V (DVD-video) supports data compressed Dolby Digital (AC-3) or DST codec stereo / 5.1 multichannel[ref].
The main matter of bitrate is storage space spacing. So we need to choose the minimal bitrate, that gives proper sound quality.
As rule, 256 kbit/sec and more is recommended.
But, if you want to define own optimal bitrate, here step-by-step guide:
- Take several lossless files (FLAC, WAV, AIFF or other) as samples of your preferable musical genres.
- Encode these samples to mp3-audio with different bitrates.
- Compare these mp3 files with its originals by audibility of sound quality difference.
- To future coding, you can use minimal bitrate, that causes a minimal audible difference.
DSF, DFF, SACD ISO (*.iso) are lossless DSD formats based on 1-bit sigma-delta modulation.
This format allows to using simplified (in concept) digital-to-analog converters, comparing PCM ones.
DFF and SACD ISO (file-image of SACD optical disk) may be DST compressed.
DSD audio content may be packed in DoP format (not compressed). DoP is stored in lossless PCM files (WAV, FLAC).
As rule, DFF has metadata displaying issues for playback tools. SACD ISO contains text metadata only.
Stereo and multichannel
SACD ISO may contain 2 variants of single album stereo and multichannel. It causes consuming of additional space at hard disk.
To avoid the consuming SACD ISO may be extracted to DSF files with the certain channel number. As an example, for a stereo digital audio player, stereo album variant is the best option.
Also, SACD ISO file doesn't contain album artworks.
Wireless Bluetooth protocol uses several types of audio codecs. They are need to improve sound quality and latency for available throughput ability of the wireless equipment.
|AAC||up to 250 kbps|
|LDAC||up to 990 kbps||about 250...550 ms||up to 24 bit 96 kHz||
|LHDC||up to 900 kbps||up to 96 kHz|
|LLAC / LHDC LL||400 / 600 kbps||30 ms||up to 24-bit 48 kHz|
|AptX||up to 352 kbps|
|AptX HD||up to 576 kbps||170 ms||24-bit 48 kHz|
|AptX LL||up to 40 ms|
|AptX Adaptive||279 ... 420 kbps||80 ms||back
||lossless 44.1 kHz 16 bit, lossy 24-bit / 96kHz||introduced by Qualcom in 2021|
|SBC||up to 320 kbps|
|LC3||160 kbps or 80 kbps for each of 2 stre
||lost audio data management|
Is LDAC better than aptX?
Looks like, LDAC has not lossless ability. In contrast, AptX lossless can it. However, LDAC supports 24 bit / 96 kHz. AptX in lossless mode supports CD quality only (44.1 kHz / 16 bit).
Theoretically, high resolution brings better sound quality. But, many factors impact to sound quality. Read more...
An audio codec is a program to convert original audio data stream to certain format and back. Audio codec provides bit/byte order, data headers, compression/decompression and other.
Original audio stream is a raw sequence of non-formatted digital audio data.
As rule, audio codecs are included to audio conversion software and program or hardware players.
Example of audio codec types:
mp3 codec, flac codec, aac codec, other.
iTunes audio player software allows to playback both audiophile and lossy formats. But there is a limitation: iTunes don't play FLAC and DSD files. Also, iTunes can't read WAV metadata.
FLAC may be replaced to Apple Lossless Codec (ALAC with *.m4a extension).
WAV may be replaced to AIFF. However, metadata (text and artwork) should be stored in a format compatible with iTunes.
When you choose the best audio format for the sound quality of your music library, it needs to consider:
- compatibility with used software and hardware;
- desirable sound quality (maximal for your audio system);
- desirable number songs in limited hard disk space of computer or musical device.
Extracting of stereo tracks from SACD ISO (with stereo and 5.1 album variants)
and/or downmixing of multichannel tracks to stereo
can save hard disk space at stereo digital audio players (DAP) and mobile phones.
Operating system of computer or mobile phone doesn't impact to sound quality of played back files. It is a matter of playback system settings rather.