Normalize audio to the right LUFS target for each platform

Short answer: for Spotify, YouTube, Tidal and Amazon Music, aim for an integrated loudness of about -14 LUFS. For Apple Music and most podcast platforms, -16 LUFS. Broadcast TV in Europe is -23 LUFS, in the US -24 LKFS. Master louder than the target and the platform just turns you back down, so you gain no loudness and lose the dynamics you spent.

You can measure your own file right now. Load it into the browser volume booster and hit Smart Boost. It runs a real ITU-R BS.1770-4 loudness meter over every sample and reports sample peak in dBFS, RMS in dBFS and integrated loudness in LUFS. Nothing uploads. The measurement happens in your tab; turn Wi-Fi off after the page loads and it still works.

Peak, RMS and LUFS are three different things

People use "how loud is it" for three separate measurements, and mixing them up is where most bad advice starts.

Peak is the tallest single sample in the file, in dBFS. A file that peaks at -0.3 dBFS has 0.3 dB of room left before digital full scale. Peak tells you about clipping risk and nothing else. A recording of one hand clap in an otherwise silent room can peak at -0.1 dBFS and still sound like near-silence.

RMS is the root mean square of the samples, which tracks average energy over time. It correlates with perceived loudness far better than peak does, but it treats a 40 Hz rumble and a 3 kHz snare crack as equally loud. Your ears do not.

LUFS fixes both problems. Loudness Units relative to Full Scale runs the signal through a K-weighting curve that approximates how your hearing responds (a high-pass that drops the deep bass, plus a shelf that lifts everything above roughly 2 kHz by about 4 dB), then measures energy in 400 ms blocks that overlap by 75 %. Then it gates. Blocks measuring below -70 LUFS are thrown out entirely, and a second, relative gate discards blocks more than 10 LU below the average of whatever survived the first pass.

Without the gate, a three-minute podcast with 40 seconds of room tone at the top would measure far quieter than it sounds. The gate ignores the silence and measures the parts you actually hear. One more useful fact: 1 LU equals 1 dB. If your file measures -19 LUFS and you want -14, you need exactly 5 dB of gain. No conversion table required.

The real platform targets

These are normalization reference levels, not rules. Nothing gets rejected for missing them; they describe what the platform's playback gain aims at.

Platforms adjust these occasionally, so treat the table as a snapshot. The 2 LU spread between streaming services matters less than you'd think: 2 dB is a small perceptual step.

Why a louder master gets turned down anyway

Loudness normalization is what ended the loudness war for streaming.

Say you crush your master to -8 LUFS with heavy limiting. Spotify measures it at -8, subtracts 6 dB to bring it to -14, and plays it back at exactly the same perceived loudness as the person who mastered to -14 with all their transients intact. You spent 6 dB of dynamic range and got nothing. Worse: your snare has no punch left, and the two files sit side by side in a playlist at matched volume, where yours sounds flat.

The reverse case is more interesting. If your file measures -24 LUFS, Spotify turns it up 10 dB. YouTube mostly won't. That's why quiet YouTube uploads stay quiet while the same file on Spotify sounds fine. Raise a quiet mix yourself rather than hoping the platform will.

How to normalize audio to -14 LUFS

The tool measures and tells you the gain. It doesn't silently re-master your file to a target behind your back. You read the number and move the slider.

1. Drop your file on the volume booster page. Nothing uploads. No sign-up, no length limit beyond your device's memory.
2. Click Smart Boost. Read the integrated LUFS figure.
3. Subtract. If it reads -19.6 LUFS and you want -14, the gain you need is 5.6 dB.
4. Convert dB to a percentage: 10^(dB/20). 5.6 dB is 1.905, so set the slider to 190 %. The slider runs 0 to 500 %, and 100 % is the untouched file.
5. Check the clip warning. It names the percentage of the file that would run past full scale at the current setting. If it reads anything above zero, either leave the soft limiter on or back the slider off.
6. Export as WAV (16-bit, 24-bit or 32-bit float). Rendering happens offline, faster than real time.

Handy conversions so you don't need a calculator: 141 % is +3 dB, 200 % is +6.02 dB, 300 % is +9.54 dB, 400 % is +12.04 dB, and 50 % is -6.02 dB. Doubling the amplitude is always 6.02 dB, at any level.

Smart Boost also reports the exact percentage that produces zero clipped samples, with 1 dB of margin below full scale, and one click applies it. That's your ceiling for a completely clean gain change. Sometimes it sits above the number you need for -14 LUFS, sometimes below it. When it's below, your file has less headroom than the target wants, and you have a decision: accept a lower loudness, or let the soft limiter take the peaks.

The limiter is on by default. It's a tanh-knee waveshaper: transparent below 0.7 of full scale, then asymptotic to full scale above it. It's a limiter, not a compressor, so there's no attack or release to set and no pumping. It catches peaks. That's all.

Peak normalization vs loudness normalization

Peak normalization means scaling a file so its loudest sample lands on a chosen ceiling, usually -1 or -0.1 dBFS. That's what the "Normalize" button in most audio editors does.

It is close to useless for matching perceived loudness. Two files peak-normalized to -1 dBFS can differ by 12 LU. A sparse acoustic guitar track with one hard string attack hits the ceiling immediately and stops there, still sounding quiet. A dense, limited mix hits the same ceiling and sounds enormous.

Loudness normalization scales the file so its measured LUFS lands on a target, then checks whether that gain caused clipping. That is what streaming platforms do. It's why an album peak-normalized in an editor sounds ragged track to track while the same album loudness-normalized sounds even.

Use peak normalization for one thing only: making sure nothing clips. Use LUFS for anything about how loud it sounds.

When -14 LUFS is the wrong number

Podcasts and spoken word want -16 LUFS, and the reason isn't arbitrary. A well-recorded voice is peaky. Plosives and hard consonants routinely sit 12 dB or more above the average level, so pushing speech to -14 usually means limiting those transients hard enough to hear it. -16 sits under a -1 dBTP ceiling with much less work, and it's the level podcast apps expect. Mono podcast files target -19 LUFS on Apple's guidance, because a mono file played through both speakers effectively gains about 3 dB.

Video for YouTube follows the same -14 idea. Here's the honest limit of the browser tool: the video volume page plays your MP4, MOV or WebM with the audio boosted live and exports the boosted audio as WAV. It does not re-encode the video file. To ship a louder video you take that WAV back into your editor and mux it. No browser tab can do it, and any site claiming otherwise is uploading your file to a server.

For a mix that measures fine but sounds thin or muddy, loudness isn't your problem. A 5 dB gain change won't fix a frequency balance issue. The five-band equalizer is the tool for that: peaking filters at 60, 230, 910, 3000 and 14000 Hz, Q of 1.0, plus or minus 12 dB each, with a live response curve. Its level-matched A/B is built for this decision: it trims the processed signal back to the original's peak, so you compare tone against tone instead of being fooled by the louder version always sounding better. That bias catches everyone. If the fix is purely low end, the 120 Hz low shelf gives you 0 to +12 dB without touching anything above it.

What none of this can do

Normalizing a file changes the file. It does not change your device. Nothing running in a browser tab can raise your phone's or laptop's system volume past its maximum, and no app on iOS can either, whatever the App Store screenshots imply. What a boosted file gets you is more of your existing output ceiling used up by the actual content.

The tool also can't touch DRM-protected streaming audio, remove noise, split stems or export MP3. WAV out only, at 16-bit, 24-bit or 32-bit float. If you need MP3, encode the exported WAV afterwards in whatever you already use.

If you want the same five EQ bands and the same genre presets on your phone, with a library that remembers settings per track, the Increase Volume app for iPhone and the Android version do that offline. They boost to 200 % rather than 500 %, and they have no limiter and no level-matched A/B. On measurement and safety the website is ahead.