MP3 Converter online

What MP3 Converter does

Audio conversion decodes the sound and encodes it again in another format. MP3 Converter uses FFmpeg: MP3 is encoded with LAME, OGG with Vorbis, OPUS with libopus, AAC and M4A with the FFmpeg AAC encoder, FLAC as lossless audio and WAV as uncompressed 16-bit PCM. When the input is a video, the picture is ignored and only the sound is converted.

Typical reasons are a device or app that only plays certain formats, a recording that is too large, or a lossless master that needs a smaller copy for a phone.

How to use MP3 Converter

1. Drop your MP3, WAV, OGG, AAC, M4A, FLAC, OPUS, MP4, MOV, AVI, WEBM, MKV, FLV, WMV, and 3GP files into the box, or click to choose them.
2. Pick the output format and any options.
3. Click Convert. The conversion runs on your device.
4. Download each file, or all of them at once as a ZIP.

When to use MP3 Converter

• Convert a FLAC or WAV recording to MP3 or M4A so it fits on a phone and plays on any car stereo.
• Turn a voice memo saved as M4A into MP3 for a website, a podcast host or an older media player.
• Save a song or sound effect as OGG for a game engine or web project that expects the Vorbis format.
• Convert an MP3 to WAV so it can be imported into audio editing or DJ software that only accepts uncompressed files.

Settings explained

Output format

Picks the format of the new file. MP3 plays everywhere, M4A suits Apple devices, OGG and OPUS suit web projects and games, and FLAC or WAV store the decoded audio without further loss.

Bitrate

Sets the data rate for lossy formats, from 64 to 320 kbps. The default of 192 kbps suits music, and 128 kbps suits speech. For OGG it picks a matching Vorbis quality level. Not shown for WAV and FLAC.

Mono

Mixes the left and right channels into one channel. This roughly halves the size of WAV and FLAC files and helps lossy formats sound better at low bitrates. Use it for speech, not for stereo music.

Format comparison

What is MP3?

MP3 (MPEG-1 Audio Layer III) is an audio format introduced by Fraunhofer IIS in 1993. It uses lossy compression. Files use the .mp3 extension.

MP3 is audio layer III of the MPEG-1 and MPEG-2 standards, developed mainly at the Fraunhofer Institute in Germany. It uses a model of human hearing to remove sounds that most listeners cannot hear, which made music files about ten times smaller than CD audio. Its patents have now expired.

MP3 is the best choice when an audio file must play on every possible device, for example podcasts, music collections, audiobooks and voice recordings shared with many people. A bitrate of 192 to 320 kbps suits music well.

MP3 is less efficient than AAC or Opus, so it needs a higher bitrate for the same quality. At low bitrates, cymbals and high tones can sound watery. Converting from one lossy format to another always loses some quality.

MP3 plays in all web browsers, on Windows, macOS, Linux, Android and iOS, and on car stereos, smart speakers, TVs and older portable players. It is the most widely supported audio format.

What is WAV?

WAV (Waveform Audio File Format) is an audio format introduced by Microsoft and IBM in 1991. It uses lossless compression. Files use the .wav extension.

WAV is an audio file format from Microsoft and IBM based on the RIFF container. It usually stores uncompressed PCM audio, the same type of data used on audio CDs, so every sample is kept exactly. Its file size depends only on the sample rate, bit depth, number of channels and duration.

WAV is the right choice for recording, editing and mastering audio, for sound effects in software and games, and as a master copy before you create MP3, AAC or other compressed versions.

Uncompressed WAV files are large, about 10 MB per minute for CD quality stereo. A standard WAV file cannot be larger than 4 GB. Support for tags such as artist and album is weak compared with MP3 or FLAC.

WAV plays in all major web browsers, on Windows, macOS, Linux, Android and iOS, and in every audio editor and digital audio workstation. Some hardware players and car stereos do not support it.

What is OGG?

OGG (Ogg (Vorbis audio)) is an audio format introduced by Xiph.Org in 2000. It uses lossy compression. Files use the .ogg or .oga extension.

Ogg is an open container format from the Xiph.Org Foundation, and files with the .ogg extension usually contain Vorbis audio. Vorbis is a royalty-free lossy codec created as a free alternative to MP3. The same container can also hold Opus, FLAC or Theora video, which can confuse some players.

Ogg Vorbis is a good choice for audio in games, open source software and projects that need a royalty-free format. It gives better quality than MP3 at the same bitrate, especially at medium and low bitrates.

Apple devices, some car stereos, hardware players and editing tools have limited support for Ogg. Vorbis is no longer actively developed as a codec, and Opus is generally recommended for new royalty-free audio.

Chrome, Edge and Firefox play Ogg Vorbis, while Safari support is limited and depends on the version. Android plays it natively. On Windows and macOS, VLC and many media players open it, but some built-in apps do not.

What is AAC?

AAC (Advanced Audio Coding) is an audio format introduced by MPEG in 1997. It uses lossy compression. Files use the .aac extension.

AAC was standardized by MPEG as the successor to MP3 and is part of the MPEG-2 and MPEG-4 standards. It gives better quality than MP3 at the same bitrate. Profiles such as AAC-LC and HE-AAC cover uses from high quality music to low bitrate streaming. Standalone .aac files usually use the ADTS format.

AAC is a good choice for music and voice on phones, for video soundtracks and for streaming. It is the usual audio codec in MP4 videos and is widely used on Apple devices, YouTube and internet radio.

Standalone .aac files have poor support for tags and cover art, so music is usually stored as M4A instead. AAC encoders and devices are subject to patent licensing. The quality depends strongly on the encoder used.

AAC plays in all major browsers, on Windows, macOS, Android and iOS, and on most phones, cars, TVs and game consoles. Some older software cannot open standalone .aac files even though it plays AAC inside M4A or MP4.

Why use FansBond MP3 Converter

Most online converters upload your files to their servers. FansBond MP3 Converter does the work inside your browser instead, using WebAssembly and modern browser APIs. Your files stay on your device, which is safer for private photos, contracts and unreleased work, and it is often faster because nothing has to upload or download.

There are no queues, no watermarks and no account. Once the page has loaded, the tool keeps working even on a slow connection.

Tips for the best result

• Converting a low-bitrate MP3 to a higher bitrate or to FLAC does not bring back lost detail. It only makes the file bigger.
• Choose M4A instead of AAC when you want tags and wide player support. Plain AAC files are a raw audio stream without title or artist information.
• Add several files at once to convert a whole album. They are processed one after another, and you can download them together as a ZIP.
• WAV output is 16-bit. If your source is a 24-bit studio recording and you need to keep its full resolution, choose FLAC instead.

How MP3 Converter works in your browser

Video and audio are processed with FFmpeg, the open-source media toolkit behind most video software, compiled to WebAssembly. Video is encoded with H.264 for MP4, MOV and MKV, VP8 for WebM, and audio with AAC, MP3, Vorbis, Opus or FLAC depending on the format.

WebAssembly FFmpeg runs on your device's processor without a server. It is slower than a native desktop app, so a long video can take a few minutes. Keep the tab open until the progress bar finishes.

Privacy and security

Most online converters upload your files to a server, process them there and keep a copy for some time. MP3 Converter works differently: the code is downloaded to your browser once, and your files are read and written only on your device.

You can check this yourself: after the page has loaded, turn off your internet connection and the tool still works. This makes it safe for contracts, IDs, medical records, private photos and unreleased work.