How to Normalize Audio: What It Does and When to Use It (or Not)

Your recording is in, but the waveform is a thin little line. Or you have ten samples that are all slightly different in volume. Then you spot the Normalize button in your DAW or in Audacity and think: that'll fix it. Sometimes it does. Sometimes it makes things worse. In this article you'll learn what normalizing audio actually does, the difference between peak and loudness normalization, when to use it and when not to, and how to do it in Audacity, FL Studio and Logic Pro.

Short answer: what is audio normalization?

Normalizing means turning the volume of an entire file up or down in one go until it hits a target level. The whole file gets the same volume change, so the balance between quiet and loud parts stays exactly the same.

• Peak normalization sets the volume so the highest peak lands on a level you choose, for example -1 dB.
• Loudness normalization doesn't look at the highest peak, but at how loud the whole thing sounds, measured in LUFS. That's what Spotify and YouTube do with your song.
• Normalizing is not compression and not a limiter. It doesn't make your track fuller or tighter, only louder or quieter.

Peak normalization: the button in your DAW

When a program says "Normalize", it almost always means peak normalization. It finds the loudest sample in your file and works out how many dB it can add before hitting your target. Exactly that amount gets added to the whole file.

An example: your recording peaks at -12 dB and you normalize to -1 dB. Everything goes up 11 dB. The peak lands at -1 dB, but the quiet parts go up 11 dB too. So does the hiss, the fridge in the background and your breaths.

That's why peak normalization is bad at matching different songs. A track with one loud hit and quiet parts everywhere else will still sound quiet after normalizing, because that one peak decides how much can be added.

Loudness normalization: what Spotify does

Loudness normalization uses an average over the whole song, in LUFS. That way two tracks with very different peaks can still sound about equally loud. More on that unit in what is LUFS.

According to the Spotify for Artists support page on loudness normalization, this is how it works there:

• Spotify plays tracks at -14 LUFS by default, measured according to the ITU 1770 standard.
• Premium listeners can choose Loud (-11 LUFS), Normal (-14 LUFS) or Quiet (-19 LUFS).
• A louder master gets turned down. A quieter master gets turned up, but only as far as the peaks allow: Spotify leaves 1 dB of headroom. Spotify's own example: a track at -20 LUFS with a true peak of -5 dB only goes up to -16 LUFS.
• An album is normalized as a whole, so the balance between tracks stays the same.
• The web player and third-party devices, like TVs and speakers, don't use normalization.

The key thing to get: Spotify already normalizes your song for you. You don't need to normalize your master yourself to compete on Spotify. What does matter is that your master sounds clean and your true peak isn't too high. All the numbers are in how many LUFS for Spotify.

When is normalizing useful?

• Making a quiet recording usable. A voice memo, a quiet take or an interview you want to edit. After normalizing you can see the waveform better and you don't have to crank everything to hear it.
• Getting samples roughly level before you start working with them, so you don't have to touch the gain on every one-shot.
• A demo, voice-over or podcast clip you want at a decent level before sharing it.
• Making a bunch of separate files sound equally loud, like a playlist of demos or your own recordings. Use loudness normalization for that, not peak.

When shouldn't you normalize?

• On your master to make it louder. If there's already a limiter on it, the peak is already just under the ceiling. Normalizing adds nothing or pushes the peak even closer to 0 dB. On Spotify you get set back to -14 LUFS anyway. Want it louder for real? Read how to make your song louder without distortion.
• Every recording to 0 dB before mixing. Then all your plugins are hit hard and there's no room left. Leave some headroom. How to handle that is in gain staging in FL Studio and Logic Pro.
• On stems or a mix going to a mixing or mastering engineer. They want your files with their original balance and enough headroom. See how much headroom to leave for mastering.
• To rescue a noisy recording. Normalizing turns the noise up just as much as your voice. Remove the noise first, then normalize.

How to normalize audio, step by step

In Audacity

1. Select the audio, or everything with Ctrl+A (Cmd+A on a Mac).
2. Go to Effect > Volume and Compression > Normalize.
3. Leave Remove DC offset on. That centers the waveform neatly around the zero line.
4. Enter your target at Normalize Maximum Amplitude to. According to the Audacity manual, the default is -1 dB, which is a fine choice.
5. Leave Normalize stereo channels independently off, unless left and right are really different in level. With it off, both channels get the same change and your stereo image stays intact.
6. Click Apply (or OK, depending on your version).

In FL Studio

• In Edison: open your audio in Edison, select the part you want to adjust and click the Normalize button in the toolbar. According to the Image-Line manual, a left-click normalizes your selection and a right-click normalizes each region separately.
• For a sample in a Sampler channel: open the channel settings. Under the precomputed processes you'll find Normalize, which according to Image-Line maximizes the sample volume without clipping. Handy for drums and one-shots that come in too quiet.

In Logic Pro

Choose File > Bounce > Project or Section. The bounce window has a Normalize menu with three options:

• Off: nothing is changed.
• Overload Protection Only: the level only goes down if something would clip. Quieter audio isn't raised.
• On: Logic finds the highest peak and makes everything as loud as possible without clipping.

Bouncing a master that already has a limiter on it? Choose Off or Overload Protection Only. That way you know what you hear is what you export.

In your browser, to -14 LUFS

Want to match a file by loudness instead of peak, without a DAW? With Audio Converter Pro you can switch on Loudness -14 LUFS in the free audio converter. Your file then lands at the level Spotify and YouTube use, with a -1 dB limiter so nothing clips. Pro also lets you convert multiple files at once, handy for a folder full of demos. Your audio isn't uploaded: everything happens in your browser.

Check what you did afterwards

Normalizing means trusting a single number blindly. So drop the result into the free master checker. You'll see the integrated LUFS, the true peak and how much Spotify, YouTube and Apple Music turn your track up or down. Is your true peak above -1 dBTP after a peak normalization? Then you have peaks between the samples. Read more in what is true peak.

FAQ

Does normalizing reduce quality?

No, as long as you don't go above 0 dB. You're only changing the volume of the whole file. But everything goes up with it, including noise and background sounds.

Is normalizing the same as a compressor?

No. A compressor makes the difference between quiet and loud smaller. Normalizing doesn't change that difference: the whole file goes up or down by the same amount.

Do I need to normalize my song for Spotify?

No. Spotify does that itself, to around -14 LUFS by default. Focus on a clean master with a true peak below -1 dBTP, or below -2 dBTP if your master is louder than -14 LUFS, as Spotify recommends.

What level should I normalize to?

For a single recording you want to edit or share, -1 dB peak is a safe choice, and it's also the default in Audacity. If you want multiple files to sound equally loud, use loudness normalization in LUFS.

What's the difference between normalizing and gain?

With gain you choose how many dB to add or remove. With normalizing the program works that out for you based on a target level.

Need help with your mix or master?

Normalizing gets the level right, but it doesn't fix the balance between your vocal and the beat. Want someone to finish your track? Get it mixed and mastered by NameOnTheBeat, vocals only or vocals and beat. More free help in our free music tools.

Sources: Spotify for Artists, "Loudness normalization" (support.spotify.com); Audacity Manual, "Normalize" (manual.audacityteam.org); Image-Line, FL Studio manual: Edison and Sampler channel settings (image-line.com); Apple, Logic Pro User Guide, "Bounce a project to an audio file" (support.apple.com).