WAV vs AIFF vs FLAC: Choose an Audio Storage Format

If you record voice, music or call audio and want to keep it without quality loss, the usual candidates are WAV, AIFF and FLAC. All three can hold audio losslessly, so the decision is about where the files will be opened, how much storage they use and what extra information travels with them.

Define the alternatives

WAV is a container developed by Microsoft and IBM on the RIFF structure. In practice it almost always holds uncompressed PCM audio. Broadcast Wave (BWF) is a WAV variant that adds a chunk for a description, originator and time reference, and it is common on field recorders.

AIFF is Apple's equivalent, built on the IFF structure. Standard AIFF stores uncompressed PCM. The AIFF-C variant can also hold compressed or floating-point data, but most AIFF files you will encounter are plain PCM.

FLAC is an open, royalty-free codec that compresses audio losslessly: decoding returns exactly the original samples. A FLAC file is smaller than a WAV or AIFF file of the same audio, though how much smaller depends on the material.

This comparison covers storing and exchanging recordings, not lossy formats such as MP3 or AAC. None of the three formats improves a recording: background noise, a clipped input level or audio captured from the wrong input device is preserved identically in each.

Compare meaningful differences

Audio data

At the same sample rate and bit depth, all three formats hold identical audio, and converting WAV to FLAC and back yields the same samples. The notable exception is floating-point audio: FLAC stores integer samples only, so a 32-bit float recording cannot be kept in FLAC without converting it to integer. WAV can store float directly, as can AIFF-C where your software supports it.

File size and limits

WAV and AIFF size grows in direct proportion to sample rate, bit depth, channel count and duration. FLAC reduces that size, with quiet or simple material usually compressing more than dense or noisy material. Standard WAV and AIFF use 32-bit size fields, which caps the size of a single file; very long or multichannel recordings may be split by the recorder or written in an extended format such as RF64.

Compatibility

WAV is the most widely accepted of the three across operating systems, audio and video editors, transcription tools and hardware recorders. AIFF is well supported in Apple software and most professional audio applications, and less consistently elsewhere. FLAC is widely supported by media players and many editors, but support in some DAWs, video editors, hardware devices and upload forms is missing or depends on the version, so check the exact app before committing to it.

Metadata and tags

FLAC has a standardized tagging scheme (Vorbis comments) and embedded cover art that players generally read well. WAV tagging is less consistent: INFO chunks, ID3 chunks and BWF fields are each read by some applications and ignored by others. AIFF files often carry ID3 tags. If tags matter to your workflow, test a tagged file in the applications you actually use.

Editing and processing

Editors read WAV and AIFF directly, while FLAC must be decoded. Some applications import FLAC by converting it to an uncompressed copy first, which costs disk space and time. Encoding to FLAC also takes processing time; the FLAC compression level changes file size and encoding time, not audio quality. Actual speed depends on your hardware and settings and is something to test rather than assume.

Privacy and file handling

None of these formats encrypts audio. Depending on the device or software that created a file, its metadata may include a recorder model, dates, names or notes, so inspect and clear tags before sharing. Online converters upload your file to someone else's server; check how that service stores and deletes files, or convert locally to keep recordings on your own machine.

Practical trade-offs

Some properties are guaranteed by the format specifications: lossless storage in all three, uncompressed PCM in standard WAV and AIFF, integer-only samples in FLAC, and an embedded checksum of the decoded audio in FLAC that lets a decoder detect corruption. Other questions need a test on your own files and setup: how much space FLAC saves, how long encoding takes, and whether your apps open the file and display its tags.

• Editing a podcast, voice-over or call recording: WAV is the lowest-friction working format because nearly every editor and transcription tool accepts it.
• Working mainly in Apple software: AIFF and WAV both work; pick the one your collaborators and tools already use.
• Archiving a large library: FLAC saves storage while staying lossless, and its checksum helps confirm files are intact later.
• Recording in 32-bit float: keep WAV, since FLAC would require converting to integer samples.
• Sending files to another person or service: default to WAV unless the recipient asks for something else.

Choose for the use case

There is no universal winner. Choose WAV when maximum compatibility or float audio matters, AIFF when an Apple-centered workflow or collaborator expects it, and FLAC when storage space and reliable tagging matter and every app that needs the files can open them. Many people record and edit in WAV, then archive finished material as FLAC.

• Note the sample rate and bit depth of the original recording and keep them when converting unless the destination requires different values.
• Check whether the recording is 32-bit float before choosing FLAC.
• Open a converted test file in every app and on every output device you plan to use, and confirm its tags appear as expected.
• After converting, verify that the file decodes and that its duration and channel count match the original.
• Keep the original files until the converted copies are verified.