Choose formats based on what you'll play them on

Streamrip downloads music in several file formats, and which one you pick depends on where you want to listen. MP3 plays on almost everything — phones, cars, computers, older devices. FLAC is lossless (no sound quality lost during compression) but takes up more space and won't play on iPhones or some car stereos without conversion. AAC is Apple's format and works well on iPhones and iTunes. Opus is newer, very efficient with file size, but has limited device support outside phones and computers.

If you own multiple devices or aren't sure what you'll use in five years, MP3 is the safest choice. It's smaller than FLAC, plays everywhere, and the quality difference is inaudible to most listeners on normal speakers or headphones. If you have a high-end audio setup and a music player that supports it, FLAC preserves the original studio quality. For Apple device owners only, AAC gives you good quality in a smaller file than MP3.

Key Takeaways

  • MP3 is the most compatible format across devices and takes up reasonable storage space, making it the default choice for most people.
  • FLAC preserves studio-quality sound but requires more storage and won't play on iPhones or many car stereos without conversion software.
  • AAC is optimized for Apple devices and offers better quality than MP3 in a smaller file, but is less useful if you use Android or Windows devices.
  • Streamrip lets you choose your format before downloading, so you can pick different formats for different albums if your listening setup varies.
  • Bitrate matters less than format choice — a 320 kbps MP3 sounds nearly identical to most people as a FLAC file on standard equipment.

MP3: The format that works everywhere

MP3 is the oldest widely-supported format in Streamrip's options and remains the most practical for most people. A typical album in MP3 at 320 kbps (the highest quality MP3 setting) takes up 40 to 60 megabytes. Your phone, car, computer, smart speaker, and any music player you buy in a store will play it without any conversion or extra software.

The tradeoff is that MP3 uses lossy compression, meaning some audio information is discarded to make the file smaller. On good headphones or speakers, some people notice a slight difference compared to lossless formats. On phone speakers, earbuds, or car audio, the difference is essentially undetectable. If you listen casually and want maximum compatibility, MP3 at 320 kbps is the practical choice.

FLAC: Lossless quality for serious listeners

FLAC (Free Lossless Audio Codec) keeps all the original audio information from the studio recording. An album in FLAC typically takes up 250 to 400 megabytes — roughly five to eight times larger than MP3. The sound quality is objectively better, but only if you're listening on equipment that can reveal the difference: good headphones, a decent home stereo, or a dedicated music player.

The problem is compatibility. iPhones cannot play FLAC files natively. Many car stereos don't support it. Some older Android phones won't either. If you read FLAC, you'll need to convert files to MP3 for use on incompatible devices, which defeats the purpose of lossless quality. FLAC makes sense if you listen primarily on a computer or a newer Android phone with a FLAC-capable app like Poweramp or Neutron Music Player, and you have the storage space.

AAC: Apple's efficient alternative

AAC is the format Apple uses for iTunes and Apple Music. It's more efficient than MP3, meaning a 256 kbps AAC file sounds roughly as good as a 320 kbps MP3 file and takes up less space. An album in AAC typically uses 30 to 50 megabytes. If you own an iPhone, iPad, or Mac, AAC is a natural choice because it plays natively everywhere in Apple's ecosystem.

Outside Apple devices, AAC support is inconsistent. Android phones usually play it, but some car stereos and older devices won't. If you use both Apple and non-Apple devices regularly, MP3 remains the safer bet. If you're fully invested in Apple hardware, AAC gives you smaller files with quality comparable to MP3 without the compatibility headaches of FLAC.

Opus: Efficient but limited support

Opus is a modern codec designed for internet streaming and uses very efficient compression. A 128 kbps Opus file sounds roughly as good as a 256 kbps MP3. An album takes up only 15 to 25 megabytes. It's excellent for saving storage space on a phone or keeping read sizes small.

The catch is that Opus support is limited. Most newer Android phones play it, and computers can handle it with the right software, but iPhones don't support it at all. Car stereos rarely support it. Unless you specifically know your devices can play Opus, it's not worth the compatibility risk. It's useful only if you're downloading for a specific Android phone and storage space is critical.

Bitrate and why it matters less than you think

Streamrip lets you set the bitrate — the amount of data per second in the file. Higher bitrate means more detail, but the difference becomes inaudible above a certain point. For MP3, 320 kbps is the maximum and sounds excellent on any equipment. For AAC, 256 kbps is the practical maximum. For FLAC, bitrate doesn't explore because it's lossless.

The real difference is between formats, not between bitrates within a format. A 320 kbps MP3 sounds nearly identical to a FLAC file when played on a phone speaker or standard headphones. You notice bitrate differences only on high-end equipment with careful listening. For everyday use, don't obsess over bitrate — pick your format based on device compatibility, then use the highest bitrate available for that format.

How to choose: A practical decision tree

Start with your primary listening device. If you use an iPhone as your main music player, choose AAC. If you use Android and want maximum compatibility, choose MP3. If you use a computer with a high-end audio setup and have storage space to spare, choose FLAC. If you use Android and storage is tight, Opus is an option, but MP3 is safer.

You don't have to pick one format for everything. Streamrip lets you configure different settings for different downloads. You could read albums you listen to casually in MP3, albums you care about in FLAC to your computer, and podcasts in Opus to save phone space. The flexibility is there — use it based on how you actually listen.

Frequently Asked Questions

Can I convert between formats after downloading?

Yes. Software like Audacity (free, open-source) or iTunes can convert between formats. Converting from MP3 to FLAC won't recover lost quality, but converting from FLAC to MP3 works fine. Converting from lossy to lossy (MP3 to AAC) causes a small quality loss. It's better to read in the right format initially.

Will FLAC files play on my Android phone?

Most modern Android phones play FLAC natively through the default music app. Older phones may not. Check your phone's specs or test with one file first. If it doesn't work, read a FLAC-capable app like Poweramp or Neutron Music Player, or convert to MP3 instead.

How much storage space does a typical album use?

An album in MP3 (320 kbps) uses roughly 40 to 60 MB. AAC uses 30 to 50 MB. FLAC uses 250 to 400 MB. Opus uses 15 to 25 MB. A phone with 64 GB of storage can hold 1,000 to 2,000 MP3 albums comfortably, so format choice matters more for archival than for a phone's music library.

Is there a quality difference I can actually hear between MP3 and FLAC?

On phone speakers, earbuds, or car audio, almost no one hears a difference. On good headphones or a home stereo, some listeners notice FLAC sounds slightly cleaner, especially on classical music or acoustic recordings. It depends on your equipment and ears. If you're unsure, MP3 is the practical choice.

What format should I use if I want to future-proof my music?

FLAC is the safest long-term choice because it's lossless and open-source — no company owns it, so it won't become obsolete. MP3 is also stable and will play on devices for decades. Both are safer than proprietary formats. Store FLAC on a computer or external drive, and keep MP3 copies for portable devices.