Audio converter · Windows 10 and 11
Convert audio files between formats
One window for every sound conversion. Drop in files or whole folders, pick one of 15 formats, and Octoolo converts several at a time on your own PC. Videos go in too, when it is their sound you are after.
How to convert audio files
- 1
Open Convert sound files
Open Converters from Octoolo's home screen and pick Convert audio. The first time, Octoolo fetches FFmpeg, the engine behind every conversion (77 MB, once).
- 2
Add files or folders
Drop them on Drop sound or video files here, or press Choose files. Add more keeps adding to the list.
- 3
Pick the format and quality
Choose a tile under Convert to, or open All 15 sound formats. Then pick As it is, High, Balanced or Small.
- 4
Convert
Choose a place under Save in and press the button, which names the count and the format, such as Convert 24 files to FLAC. Up to four files convert at the same time.
The 15 formats, and what each is for
| Format | Kind | Good for |
|---|---|---|
| MP3 | Compressed | Playing anywhere: phones, cars, every player |
| M4A | AAC, or Apple Lossless | iPhone, iTunes and most phones |
| AAC | Compressed | Small files that play almost everywhere |
| OGG | Vorbis or Opus | Games and open-source apps |
| OPUS | Compressed | The smallest files, great for voice |
| WMA | Compressed | Older Windows players |
| AC3 | Compressed, up to 5.1 | Dolby Digital surround sound |
| MP2 | Compressed | Broadcast systems |
| AMR | Compressed, 8 kHz mono | Voice memos for older phones |
| WAV | Uncompressed | Editing, samplers, pro apps |
| AIFF | Uncompressed | Mac apps such as Logic and GarageBand |
| FLAC | Lossless | Music archives at about half the size of WAV |
| ALAC | Lossless | Apple Lossless for iTunes, saved as .m4a |
| WV | Lossless | WavPack archives |
| MKA | Holds any codec | Several sound tracks in one file |
Need something else? Type its extension into Find a format. If FFmpeg can write it, Octoolo offers it, with FFmpeg's own settings.
Quality presets and bit rates
Lossless formats (WAV, AIFF, FLAC, ALAC and WV) keep every bit of the sound they are given, so there is nothing to choose. For the others, Quality has four settings. As it is copies the sound untouched when the new format can hold it, which is instant and loses nothing, as when AAC goes into an M4A. Otherwise it converts at high quality and keeps a compressed source's own bit rate within the format's range. High, Balanced and Small set the bit rate in kbps:
| Codec | High | Balanced | Small |
|---|---|---|---|
| MP3 | 320 | 192 | 128 |
| AAC (M4A and AAC) | 256 | 192 | 128 |
| Opus | 192 | 128 | 64 |
| Vorbis (OGG) | 256 | 160 | 112 |
| WMA | 192 | 160 | 128 |
| AC-3 | 448 | 384 | 224 |
| MP2 | 384 | 256 | 192 |
These are stereo figures; a mono file gets half, and never less than 48 kbps. Under More settings you can pick the bit rate yourself (64 to 320 kbps), the sample rate (48, 44.1, 32, 22.05 or 16 kHz), mono or stereo, and the bit depth of lossless files: 16-bit, 24-bit, or 32-bit float for WAV.
Converting a whole library
Drop a folder and Octoolo finds the sound and video files in it, three folders deep and up to 500 at a time, listed in name order. Each row shows the file's length, format, bit rate, sample rate and size. Four convert at once while the rest wait their turn, and Stop all halts the batch whenever you like.
- The same folder as each original keeps your folder layout: every new file lands beside its source, under the same name.
- A folder I choose… collects everything in one place.
- Nothing is overwritten. If the name is taken, the new file becomes “song (2).flac”.
- If Octoolo cannot write to a folder, the file goes to an Octoolo folder in your Music folder instead, and its row says so.
When the batch is done, a summary shows how many files converted and the total size before and after. The format and quality you picked are remembered for next time.
Popular sound conversions
Each of these has its own page, with the settings that matter for that pair:
- To MP3: WAV, M4A, FLAC, OGG, WMA, AAC, Opus, AIFF, AMR, M4B and CAF, or anything at all with the MP3 converter.
- To WAV: MP3, M4A, FLAC and OGG, or any file with the WAV converter.
- Lossless: WAV to FLAC, FLAC to ALAC, and MP3 to FLAC, which keeps an MP3 exactly but cannot improve it.
- From MP3 and WAV: MP3 to M4A, MP3 to OGG, MP3 to AAC and WAV to M4A.
- From videos: MP4 to MP3, or the sound of any video.
Octoolo or an online tool?
| Detail | Octoolo | A typical online tool |
|---|---|---|
| Your files | Stay on your computer | Usually uploaded to the site's server |
| Without internet | Works | Does not work |
| File size | No limit | Often capped on free use |
| Many files | Whole folders at once | Often a few at a time |
| Watermarks and ads | None | Common on free plans |
| Cost | $4.99 a month, all 17 apps | Free with limits, or a plan per site |
Questions, answered
Which files can it convert?
Any sound file FFmpeg reads, which covers MP3, WAV, FLAC, M4A, OGG, WMA, AIFF, APE, AMR, CAF and many more, plus video files for their sound. Copy-protected files cannot be read.
Does converting lose quality?
Going to a compressed format such as MP3 or AAC leaves out some detail, very little at High. Going to a lossless format keeps everything, though it cannot bring back what an MP3 or AAC source had already lost.
How many files can I convert in one go?
A dropped folder brings up to 500 files from up to three folders down, and Add more takes more after that. Four files convert at the same time while the rest wait.
Will tags and cover art be kept?
Title, artist and album tags are copied into formats that hold them, and a cover picture is kept when the new file is MP3, M4A, ALAC or FLAC.
Can it make a format that is not in the list?
Often, yes. Type the extension into Find a format, and if FFmpeg can write that kind of file, Octoolo converts to it with FFmpeg's own choice of settings.
Is this an audio converter for Windows that works offline?
Yes. Once FFmpeg is set up the first time, Convert sound files works without an internet connection, and your files never leave your PC.
Audio converter, and 16 more apps.
Download for Windows7 days free, then from $3.99 a month for all 17 apps. Windows 10 and 11.