Audio Converter

Audio Converter

Drop an audio file, or a video file you want the sound from, into the box. Before you convert, the tool shows what you've got: format, length, sampling rate, channels and bitrate.

Pick the format you want: MP3, WAV, FLAC, M4A, AAC, OGG, Opus or WMA. Then choose a quality and, if you need to, change the sampling rate or switch between mono and stereo. When it's done, you'll see the new file's size and how much smaller it is, with a player so you can listen before you download.

Conversion runs in your browser, so your files never leave your device. Long files take a little longer, depending on your computer.

Which format to choose

Lossy formats make files small by dropping sounds you're unlikely to notice. Lossless formats keep every detail. FLAC packs it efficiently, while WAV stores it as-is.

Quality and file size

The size of a lossy file depends on its bitrate and length, not on the song. Here's a 4-minute track at each setting:

How to choose:

• 96 kbps is plenty for speech: podcasts, audiobooks, voice notes. Opus sounds good even for music at this level.
• 128 kbps is fine for casual listening. AAC, M4A and Opus sound noticeably better than MP3 at this setting.
• 192 kbps is where most people can no longer tell an MP3 from the original.
• 320 kbps is the highest MP3 setting. Use it when storage doesn't matter. For AAC and Opus, the improvement above about 256 kbps is rarely audible.

Converting can't add quality back

A file never sounds better than its source. Turning a 128 kbps MP3 into FLAC or WAV gives you a file several times bigger that sounds exactly like the MP3. The details the MP3 discarded are gone. The same goes for raising the bitrate: a 128 kbps file converted at 320 kbps is bigger, not better. The tool warns you when a setting would only do that, using the details it shows before you convert.

Each lossy conversion loses a little more. Converting MP3 to AAC, then to OGG, adds artifacts at every step. Always convert from the best copy you have, ideally a lossless one.

Sampling rate and channels

The tool keeps the original sampling rate and channels unless you change them, which is usually what you want.

Sampling rate. 44.1 kHz is the standard for music, and 48 kHz for video. If you're adding audio to a video project, convert to 48 kHz so it matches. The lower rates are for speech only: 16 kHz is enough for clear voice recordings, and 8 kHz sounds like a phone call. Raising the rate, for example from 44.1 to 48 kHz, doesn't add any detail.

Mono or stereo. For a single voice, mono sounds the same as stereo and halves the size of WAV and FLAC files. At the same bitrate, a mono MP3 or AAC puts all its bits into one channel, so it sounds cleaner than a stereo file of the same size.

Taking the sound out of a video

Drop an MP4, MKV, WebM or MOV file and choose an audio format. You get the soundtrack as a separate file, for example to save a talk as MP3 or to edit a recording's audio. Video soundtracks are usually 48 kHz, and the tool keeps that unless you change it. For more options, use the Video to Audio Converter or Video to MP3.

Album covers and tags

Titles, artists, albums and the cover image are copied over when the new format can hold them:

• MP3, M4A and FLAC store both tags and covers, and almost every player shows them.
• OGG and Opus store tags; whether the cover appears depends on the player.
• Bare AAC and WAV have little or no room for them.

If the cover matters, choose M4A rather than AAC, and FLAC rather than WAV.

FAQ

Will converting MP3 to WAV or FLAC improve the sound?

No. It only makes the file bigger. A lossless copy of a lossy file sounds exactly like the lossy file.

Why is my converted file bigger than the original?

Either you converted to WAV or FLAC, or you chose a higher bitrate than the original had. The result panel shows both sizes so you can compare.

Which format works on an iPhone?

M4A is the native choice, and iPhones play MP3 too. Both keep the cover and tags.

What's the difference between M4A and AAC?

The sound is the same. M4A wraps AAC audio in a container that also holds tags and a cover image, while an .aac file is the bare audio. Most software prefers M4A.

I just want a smaller file in the same format.

Use the Audio Compressor. To cut out a section, use the Audio Trimmer. To make quiet recordings louder, use the Audio Volume Booster.

Is my audio uploaded anywhere?

No. Everything happens in your browser, and we never see or store your files.