FLAC vs MP3: Which is the Better Format?

The intricacies of different audio formats with their respective sound quality, file sizes, and сompression algorithms are no longer reserved for industry professionals in recording studios or movie productions. Both regular users and audiophiles that want to enjoy their music collection at its finest are also looking for answers as to which format to consider besides the standard MP3 one. This overview will briefly go over the history of MP3 and FLAC - its higher-quality alternative - as well as their other characteristics and common use cases.

What is a FLAC file?

FLAC, which stands for Free Lossless Audio Codec, was first introduced in 2001 as an open-source compression format that is able to maintain identical wavelength forms in the process of encoding and decoding the original soundtrack. The equality is achieved by storing not only the mathematical formula of the expected frequency (the number of sound waves that pass a chosen point per unit time) but by also keeping the residual difference between each approximation and its actual value. Among other goals, the FLAC project was aimed at preventing audio copyright infringement.

FLAC is most commonly used for archiving music collections from CDs or vinyl recordings to preserve their quality and authenticity. By default, the FLAC format is supported by Windows 10, as well as Android, Jolla, and BlackBerry 10 devices. Other than that, you would need a dedicated media player or application to be able to listen to these tracks. To fully experience the quality that the FLAC format delivers, you would need high-end equipment. And even if you connect a proper device to a speaker set through Bluetooth, the sound won’t be lossless anymore, so make sure there are no extra codecs that interfere in the playback process.

FLAC format pros

• Enhanced audio quality is achieved by working in the lossless format. The file retains the original datum of the recording and keeps most of its frequency range intact.

• FLAC is better at reproducing higher frequencies and subtle background sounds that tend to be lost in other formats that only keep the louder and lower-tune instruments.

FLAC format cons

• You need to install special software or use a third-party application of some kind to listen to FLAC files on most devices, specifically Apple smartphones, as they do not offer native support for this audio format.

• The same audio track in MP3 will be about four times smaller in size, while the difference in quality will practically be nonexistent to an untrained ear.

• Given the higher level of compression, FLAC files need more CPU power to be decoded by device processors.

What is an MP3 file?

MP3, which stands for MPEG-1 audio layer 3, is a lossy format that reduces the accuracy of certain parts of the audio track by removing some of the frequencies that are barely audible to the human ear. For all the other amplitudes, the method stores mathematical approximations of the expected amplitudes instead of their original values. The format was made public in 1993 as an extension to MPEG, and the first song that was used to refine the compression techniques was Tom’s Diner by Suzanne Vega.

MP3 files are generated with different bit rates, which specify the desired rate of kilobits per second to keep from the original data stream. Sometimes, a variable bit rate is employed, which means the bit rate can be changed by the algorithm to retain complex parts of the audio with more precision. Lastly, MP3 files can come with compression artifacts, which are distorted sounds that were not present on the original recording caused by the discrepancies of the method during coding and decoding. A higher bit rate can mitigate the deviations in resulting quality.

MP3 format pros

• Out-of-the-box support by most music players, portable devices, smartphones, and any other common sound systems.

• A smaller file size compared to most other formats which makes for easier streaming, storage, and distribution.

• The possibility to influence the quality of resulting audio to some extent by using variable bit coding and opting for a higher rate.

MP3 format cons

• The possible loss in quality caused by the underlying methodology of storing sound data.

• The extra sounds that can result from frequency conflicts between the recovered parts of the original audio.

• Variable bit rate usage can result in a higher file size.

The main differences between FLAC and MP3

Now that we’ve considered both formats separately, you may already have a general understanding of FLAC and MP3. The three main characteristics that make them different - file size, compression, and quality - are all interconnected, and their joint effect stems from the variation in the underlying methods of dealing with the audio track.

Expectations on file size

With the highest possible bit rate of 320 kb/sec, a 3-minute audio track in the format file .mp3 would take up approximately 7 MB of storage space. The same song in FLAC would take up approximately 28 MB of storage space, about four times bigger than the corresponding MP3 file version. However, the size of an MP3 file might also be influenced by the chosen dynamic range (the difference between the maximum and minimum signal values) and bit depth (the resolution of each sound sample).

Audio compression

Compression is aimed at reducing the dynamic range by amplifying quiet sounds and decreasing the volume of loud sounds. MP3 relies on psychoacoustic modeling to perform the compression: the algorithm purposely skips or aggressively compresses the frequencies that are overpowered by other parts of the audio or are barely detectable to the human ear. FLAC files, on the contrary, use lossless compression, so all of the original sound data is reproduced with minimal changes.

Quality of sound

FLAC supports high-resolution sample rates of up to 32-bit, or 96kHz, which is better than digital CD quality. With an advanced playback system, there would be little-to-no inconsistencies between the live sound and the recording of it. As for MP3, given the approach it takes on reducing file size by compressing parts of the data stream that are considered insignificant, the resulting quality is, of course, lower than that of a FLAC file. However, the difference is quite subtle, and can only be noticed in certain conditions.

When you should use FLAC

FLAC files allow audiophiles to enjoy an incredible digital audio experience, given good headphones that support a wide frequency range, a playback device with a sound card, an exceptional recording quality of the original track, and a rather quiet setting. If you work with sound design, have a perfect pitch, or simply are a distinguished music lover, you should definitely give this format a try. Some people say it works especially well for classical music concerts with higher-frequency instruments that are cut off by MP3.

When you should use MP3

If you are a regular user that interacts with audio files when listening to music via standard headphones, laptops, or speaker sets, MP3 would be more than enough to convey the expected quality and deliver a satisfying experience. Given their smaller size and near-universal support by everyday devices, MP3 files are a better option for sharing and streaming. If you are not planning on investing in expensive sound equipment, there is probably no need to consider other file formats for the tracks you want to enjoy. Any regular search query with the name of the song or the artist will most likely lead you to an MP3.

Visual comparison: FLAC vs MP3

To summarize the information given above, you can take a look at this table of MP3 vs FLAC based on the common criteria for anyone dealing with sound. To choose the appropriate format for your use case, study the table with your use case in mind.

Do you normally listen to music while driving, jogging, or on your way to work? Do you want to be able to transfer the same playlist among all of your devices and use regular headphones or speakers? Does your device have limited storage space? If the answer to any of these questions is positive then MP3 would be your first choice.

Alternatively, do you have an advanced audio set at home where you’ve mastered the equalizer settings? Do you work with sound professionally and have a certain quality threshold to keep up with? Do you want to digitize old tracks from CDs or vinyl records? Do you have extra storage space? Give FLAC a try then.

Summary – FLAC vs MP3

Both FLAC and MP3 are able to provide a satisfying audio experience for your music collection. The quality of sound for MP3 tracks is slightly lower than FLAC due to lossy compression. Despite the existing differences in formats, you should keep in mind that to be able to hear them, you need to listen to the same soundtrack on the same media player. Otherwise, any nuances you notice might be associated with the device or audio itself rather than the format.