Audio file formats are like the hardware store of digital sound—underappreciated yet absolutely critical. Think about it: we all obsess over mics and gear, then barely consider the format that actually transports our work from our hard drive to someone else’s ears. Maybe it’s time we flip that script.

Craving top-tier clarity? WAV or AIFF files preserve every sonic nuance. If you’re posting a quick clip online and need faster load times, a compressed format like MP3 or OGG will do just fine. Pick the format that fits your actual goals—not whatever some self-proclaimed purist calls ‘best.’

Let's break down these formats without the jargon, so you can make decisions based on what actually matters for your specific project—not just what someone told you was 'professional.'

Understanding audio file formats and codecs

Audio file formats determine how sound data is stored, compressed, and played back, impacting audio quality and file size. Programs used to process audio files are called audio codecs, which encode and decode audio signals for efficient storage and playback.

The speed of audio codecs is measured in bitrate (kbps), which refers to the number of kilobits processed per second. Even within the same audio format, bitrate can vary. Generally, a lower bitrate results in a smaller file size but may lead to quality loss due to compression.

Other key factors include bit depth and sample rate. Sample rate measures the number of sound samples captured per second, while bit depth determines the detail of each sample. Higher bit depth improves dynamic range, resulting in richer sound.

Understanding your audience and where they will listen is crucial when selecting an audio file format. You need to balance accessibility with the best possible sound quality for the intended platform and device.

Compressed vs. uncompressed audio file formats

Each audio format falls into one of two categories: compressed or uncompressed. Uncompressed formats—like WAV, AIFF, and DSD—preserve all audio data, maintaining maximum quality but resulting in larger file sizes.

Compressed audio formats remove portions of data to reduce file size, making storage and sharing more efficient. Compression is classified into two types: lossless and lossy.

• Lossless audio formats. These files will ensure the sound quality is intact because it decompresses files back to their original size. They're usually much larger compared to lossy formats. File types include M4A, MQA, WMA, FLAC and ALAC.
• Lossy audio formats. Data will be lost in the transmission with lossy audio formats. Once the audio is compressed, it won't decompress back to the original size. Some quality may be lost, or degraded, but the files tend to be smaller. File types include MP3, AAC, and Ogg Vorbis (OGG).

🧠 Learn: What is an audio file converter and how do you use it?

Audio conversion tools and processes

Converting audio files between different formats is a common need for many users. Online tools such as Transloadit provide easy solutions for converting formats like MP3 to WAV. Descript also supports multiple formats, including WAV, MP3, AAC, AIFF, M4A, and FLAC, making it an excellent choice for versatile audio editing and conversion projects.

11 most common audio file formats compared

1. AAC (Advanced Audio Coding)

AAC (Advanced Audio Coding) is a lossy audio format similar to MP3 but with better quality at the same bitrate. It's widely used on mobile devices—including Android—and on platforms like Apple Music and YouTube, thanks to its efficient compression and broad compatibility.

2. AIFF (Audio Interchange File Format)

Apple developed AIFF (Audio Interchange File Format) as an uncompressed alternative to WAV. It retains all original audio data, making it ideal for professional audio work but resulting in larger file sizes.

AIFF is commonly used in professional music production for master recordings before conversion to distribution-friendly formats. However, it lacks time codes, making it less suitable for editing workflows.

3. ALAC (Apple Lossless Audio Codec)

Apple Lossless Audio Codec (ALAC) is a lossless format similar to FLAC but exclusive to Apple devices. When decompressed, it restores audio to its original quality without any loss.

Because ALAC retains all original audio data, it's favored by audiophiles and music enthusiasts. It offers smaller file sizes than uncompressed formats like WAV while preserving full audio quality.

ALAC is a great choice for archiving audio collections, ensuring that digital copies maintain the full quality of the original recordings, even if physical media are lost or damaged.

4. M4A (MPEG-4 Audio)

M4A files use AAC compression, which is a lossy format that offers better sound quality than MP3 at the same bitrate. As part of the MPEG-4 standard, M4A is widely used for digital music and podcasts.

M4A is a popular choice for digital storefronts and streaming platforms. Its balance of quality and file size makes it a preferred format for podcasts and music downloads.

5. DSD (Direct Stream Digital)

Direct Stream Digital (DSD) is a high-resolution format known for its superior sound quality but large file sizes. It's commonly used in Super Audio CDs and high-end audio playback systems but is not ideal for streaming.

DSD operates using 1-bit samples at an ultra-high sampling rate of 2.8224 MHz—64 times that of a standard CD. This design accurately reproduces high-frequency audio signals while keeping a simple bit-depth structure.

DSD was mainly used for SACDs, which aimed to surpass traditional CD quality. You’ll still find DSD files at specialty stores, mostly for audiophiles seeking the highest resolution possible.

6. FLAC (Free Lossless Audio Codec)

FLAC (Free Lossless Audio Codec) is an open-source, uncompressed format that retains all original audio data while significantly reducing file size compared to WAV or AIFF.

Unlike lossy formats like MP3 and AAC, FLAC preserves all audio information from the original recording. It is widely used for high-resolution audio storage and playback.

FLAC achieves a compression ratio of about 30% to 50%, meaning it significantly reduces file size while keeping lossless audio quality intact. This makes it a popular choice for audiophiles.

7. MP4 (MPEG-4 Part 14)

This multimedia container format supports video, audio, subtitles, images, and even text. It's based on Apple QuickTime, but has been standardized as ISO/IEC 14496-14 by the Moving Picture Experts Group.

Many sites like YouTube, Vimeo, and many others use MP4 for their video uploads due to its high compression and good quality. It's a great format for storing movies, TV shows, music videos, and other video content.

Many devices can play MP4 files, including smartphones, tablets, computers, and televisions. Given its wide acceptance, many video editing software tools support MP4, making it easier for creators to work with their content.

8. MP3 (MPEG-1 Audio Layer 3)

MP3 is one of the most widely used lossy audio file formats, offering small file sizes at the cost of some sound quality. It's a preferred choice for media players and mobile devices due to its compatibility and ease of sharing.

MP3 files are small, making them easy to transfer and download. They are compatible with virtually all devices, including smartphones, tablets, and computers, ensuring accessibility for most users.

9. OGG (Ogg Vorbis)

The name "OGG" comes from "ogging," a term from the video game "Netrek." However, over time, OGG has come to be seen less as an acronym and more as a brand or umbrella term for the various media formats developed by Xiph.Org.

Ogg Vorbis is similar to MP3s and AACs, and is an open-source codec. Spotify uses this in their streaming services, streaming at 160kbps for the free version and 320kbps for the paid version. The OGG container isn't restricted to any specific codec or format and can contain streams encoded with various codecs, such as Theora for video or Vorbis for audio.

OGG is mainly used to store audio files compressed with the Vorbis codec, which is why people call them "OGG Vorbis". Vorbis offers similar audio quality to MP3 at lower bit rates. You can also store video streams with OGG, usually using the Theora codec. It's less common than audio, though.

10. WAV (Waveform Audio File Format)

Microsoft and IBM developed the Waveform Audio File Format (WAV) for storing audio bitstreams on Windows PCs. It's based on the Resource Interchange File Format (RIFF) to store both compressed and uncompressed audio files. WAV files use the Pulse-Code Modulation (PCM) format to store uncompressed audio data, which you can encode onto audio CDs.

Suppose you're a music producer working on a new track. When recording instruments and vocals, you'd prefer the WAV format to ensure you're getting the best quality recordings.

After the recording is done, you mix and master the track using audio editing software. To prevent quality degradation, the audio remains in WAV format throughout the whole thing. You might then convert the track to a more compressed format, like MP3, for distribution or streaming, but keep the original WAV files because they're the purest, highest quality version.

11. PCM (Pulse Code Modulation)

Pulse Code Modulation is a method used to convert analog audio signals into digital files.

The analog signal's amplitude is measured (or "sampled") periodically at uniform intervals. Each of these sampled values is then rounded to the nearest value within a set of predetermined levels. Then the quantized values are then represented in binary form.

PCM was popular for CDs, but today it's used in telecommunications and music production to transmit high resolution audio and video.

Compatibility across devices and platforms

When selecting an audio file format, it's crucial to consider its compatibility with different devices and platforms. For example, AAC is widely supported on Apple devices, making it ideal for iOS users. MP3, however, is universally compatible across all platforms, including Android, Windows, and macOS.

For professional editing, WAV files are often preferred, especially in desktop applications like Descript, due to their high-quality, uncompressed nature.

How to choose the right audio file format

Choosing the right format depends on how you plan to use your audio. Sure, lossless or uncompressed files sound incredible on top-shelf gear, but many people won’t even notice a drop-off in quality if they’re just listening on average headphones or casual setups. Most of the time, you’ll want a widely recognized format for maximum compatibility. Also keep in mind that not all editing tools support every format, so pick something that your go-to software can handle.

Plus, popular audio editing programs don't support some formats, so keep that in mind if you don't have specialized editing equipment.

A few scenarios can help you decide what type of audio file format to use:

• Uncompressed audio formats. You're an audio professional who's planning on editing audio, like for a podcast. Choosing either AIFF, PCM, or WAV allows you to export a file that has high-quality audio and is easy to distribute.
• Lossless formats. You're an audiophile who wants to listen to high fidelity music with the best audio quality you can find. WMA, M4A, and FLAC files allow you to keep the data in the original recording but don't require as much storage space.
• Lossy formats. You're hoping to share your audio files online and save disk space in the process. Using AAC, OGG, or MP3 formats will result in some loss in audio quality, but you're not someone who can tell the difference, nor will the people you share your files with.

You want to choose an audio format that helps you achieve the kind of audio quality you need. Don't worry about getting super high-quality audio files if it's not essential because large files are cumbersome to convert, manage, and share.

Edit your audio files quickly with Descript

Choosing the best audio file is only the start of any podcast or video. What really matters is how you edit the files and mix them together to make voices come through clear as day. You can get this effect using Descript, the best audio editing software for creators and marketers.

Whether you're creating a podcast or editing a movie, use Descript to:

• Edit audio, remove silence, and add crossfades and effects to your projects.
• Remove filler words like "um," "uh," and "you know" with just one click.
• Create and edit content using an AI model of your voice.
• Make your dialogue sound clear and hi-res with Studio Sound.

Thousands of popular podcasts like Planet Money and Freakonomics Radio use Descript to perfect their episodes. Want to join them? Take a free tour today.

Audio file format FAQs

Frequently asked questions

Are audio files MP3 or MP4?

MP3 is an audio‑only format, while MP4 is a container that often holds both video and audio. If you just need audio, MP3 files are simpler and easier to share. If you have video (or other media) alongside your audio, you’ll need a container like MP4.

What is the best audio format for sound quality?

The best audio formats for sound quality are uncompressed or lossless compression files—think WAV, FLAC, and M4A. That's because these formats retain the original sound quality, though you'll have to put up with the fact these files will be large.

What audio file format is best for the web?

The best audio file formats to use on the web are MP3s and MP4s. They're most likely to be compatible with most web browsers such as Google Chrome and Firefox. Other formats that most browsers support include AAC, OGG, and WAV, though they tend to have large file sizes.

What is the most popular audio format?

The most popular digital audio format is MP3. It's one of the easiest file types to download and share, and it doesn't take up too much disk space compared to other file formats.

In addition, you can create MP3s with different bitrates, which can alter your file's size and quality. Due to its flexibility, many devices play MP3 files making it one of the main ways to share audio online.

What audio format is best for streaming services?

For streaming services, formats like AAC and OGG are popular choices. AAC provides efficient compression and high compatibility, making it ideal for platforms like Apple Music and YouTube. OGG is often used by services like Spotify for its open-source nature and ability to offer high-quality audio at lower bitrates.

Can I convert audio files without losing quality?

Yes, you can convert audio files without losing quality by using lossless conversion methods. Tools like Transloadit support converting between lossless formats like FLAC to ALAC, ensuring the audio remains intact during the conversion process.