In the preceding post, we discussed how YouTube’s Terms of Service govern how you download and use content. Here, then, is an article that discusses which audio format (WAV or MP3) should be used for conversion.
First, though, there are a few conditions that apply before choosing an audio format. First, you’ll need authorization to download the content from YouTube, as well as the intended use — will you play it on your phone or PC, will you want to edit it, or share it? YouTube itself has a list of its terms of service governing these actions, including how audio can be used in other works. If you’re downloading material for personal use, then you may not need additional licenses. However, any use involving others may require licensing.
The site itself also has license agreements and copyright law to consider. And finally, note that public link alone does not equal permission. The same applies to sites that offer a free YouTube-to-MP3 workflow.
As such, this article assumes that you’ve already chosen the right format, whether for playback or editing, and have determined the right way to obtain that audio file.
MP3 for everyday listening
We’re going to assume that your goal is to convert the YouTube audio to a playable format for everyday listening, whether on your phone, laptop or even your television. For this purpose, we’d recommend converting the audio to the MP3 format.
Why? Because MP3 is lossy, meaning that it compresses audio into a smaller file, but discards details intended to be less noticeable, though the loss can be audible. That means that MP3 files are small enough for compact storage, but still retain enough detail to allow high-quality listening. They are also broadly supported by virtually every consumer-level media player, both hardware and software.
Converting YouTube audio to MP3 requires three steps: first, selecting a YouTube video, then converting the audio from YouTube’s source (either directly from a public link or through a separate converter). Finally, you’ll download the converted audio. Free YT to MP3’s homepage describes MP3 conversion and download. For WAV, you’ll need to verify a separate conversion option you’re authorized to use.
PCM WAV for audio editing
If you plan to do more than simply listen to the YouTube audio, though, you’ll want to convert it to a PCM WAV format instead. Why? Because WAV is essentially the “working” file for most digital audio editors, allowing you to perform tasks like mixing, mastering, adding effects, etc., without concern for compression artifacts. But since the WAV format is largely uncompressed, it will take up significantly more space than a similarly sourced MP3.
Note that the choice between MP3 and WAV doesn’t necessarily imply that one is better than the other; rather, it reflects different goals. A working file must be compatible with the receiving application (typically some form of digital audio workstation or similar), whereas the MP3 format is simply a standard that provides good quality for most consumers.
That said, there are some considerations when converting to WAV: namely, what happens if the original audio was compressed?
If you convert YouTube audio to MP3 and then further compress it to another format like OGG or AAC, you won’t recover those discarded bits from the MP3. Those bits were discarded during lossy encoding. What you might lose, however, is more audio fidelity — detail still present before the next lossy conversion. An uncompressed working file preserves the remaining detail without adding lossy compression, though conversion to a final lossy format can discard more.
You’ll also want to avoid unnecessary intermediate conversion steps whenever possible. When converting YouTube audio to WAV directly, you’ll prevent that potential loss of quality. (Of course, if you’re using YouTube’s own toolset to do so, that may vary.) Alternatively, you could convert the YouTube video to MP3 and then from MP3 to WAV, but this adds an unnecessary step of converting the audio to a lossy format, which is not necessary if you want to preserve the original audio fidelity.
Finally, CutYT offers a direct YouTube-to-WAV conversion option for editing; only convert content you’re authorized to download and use. Otherwise, this isn’t typically an available conversion path within YouTube itself.
WAV and MP3 file sizes
How much will the conversion take up?
To put this into perspective, a five-minute audio clip will take up roughly 53 MB as PCM WAV or 12 MB as MP3 at the settings below. Here’s an example:
Duration = 300 seconds.
For example, let’s compare stereo, 16-bit audio recorded at 44.1kHz (the standard for CD audio):
PCM block alignment = channel count × bits per sample ÷ 8 = 2 × 16 ÷ 8 = 4 bytes.
PCM payload bytes = sample rate × block alignment × duration = 44,100 × 4 × 300 = 52,920,000 bytes.
So, 52.92 MB. This is a simplified calculation, excluding headers and metadata.
Now let’s look at MP3. Let’s suppose the bitrate is 320kbps, constant bit rate (CBR).
MP3 payload bytes = bitrate in bits per second × duration ÷ 8 = 320,000 × 300 ÷ 8 = 12,000,000 bytes.
So, 12 MB. Again, a simplified calculation.
These calculations don’t factor in additional data, like metadata and/or headers. So actual file sizes may differ slightly, and depend upon the converter.
Before handoff
Finally, before handoff, ensure that the receiver’s application knows what channels, sample rate and encoding were used. Most applications will export audio at documented default settings (such as Audacity’s default settings, according to its development manual):
Channels: Mono or Stereo. Custom mapping is available, too.
Sample-rate: Default documentation says 44100 Hz.
Encoding: Signed 16-bit PCM, unless otherwise specified.
Most apps will allow the user to specify their own requirements. If you know what the receiving app expects, you can adjust the output accordingly. But again, no higher output setting will restore missing source detail, because that detail simply didn’t exist.