Volume Booster & Normaliser

Volume Booster & Normaliser fixes recordings that are too quiet, too loud or uneven. Turn a whispery voice memo up by 10 dB, bring a set of podcast episodes to the same loudness, or get a track ready for Spotify without it being turned down or squashed.

There are three ways to set the level. “Louder or quieter” adds or takes away a fixed number of decibels. “Peak normalise” moves the whole file until its loudest sample lands where you choose. “Even loudness” measures integrated loudness the way streaming services and broadcasters do (ITU-R BS.1770 with gating, in LUFS) and sets each file to a platform’s target: Spotify or YouTube −14, Apple Music or podcasts −16, broadcast −23, or your own. A true-peak limiter holds even the peaks that fall between samples under the ceiling, −1 dBTP unless you choose otherwise.

“Even out loud and quiet parts” adds a compressor that brings shouts and whispers closer together. You can also mix stereo to mono, copy a mono recording to both sides, swap the sides, keep one side, or flip one side’s phase. Meters show loudness, sample peak and true peak before and after. Nothing is uploaded.

1. Press “Choose files” or drop up to 20 audio or video files on the box. The first file is measured and its loudness and peak appear under “Before”.
2. Pick what to do: “Louder or quieter” (drag the slider or tap +3, +6 or +10 dB), “Even loudness (LUFS)” with a target such as Spotify or Podcast, or “Peak normalise”.
3. Leave “True-peak limiter” ticked and pick a Ceiling. The “After” meter gives a forecast as you change the settings.
4. Optional: choose how strongly to “Even out loud and quiet parts”, change Channels, add a fade, and pick a format under “Save as”.
5. Press the button (it says what it will do, such as “Normalise to −14.0 LUFS”). Each file shows its new loudness, peak and size, and the meters switch to measured values.
6. Tap any finished file to see its meters and listen to it, then download it, or download them all as one ZIP.

• Gain from −20 to +20 dB in half-decibel steps, with quick buttons.
• Platform loudness presets: Spotify and YouTube −14, Apple Music and podcasts −16, EBU R 128 broadcast −23 LUFS, or any target from −40 to −5.
• Our own BS.1770 meter (K-weighting, 400 ms blocks, −70 and −10 LU gates), checked against ffmpeg’s EBU R 128 meter to within 0.1 LU.
• True-peak limiter with a −1, −2, −0.5 or −0.1 dBTP ceiling, using 4× oversampling to catch peaks between samples.
• “Even out” compressor in three strengths, with the loudness made up afterwards.
• Before and after meters for loudness, sample peak and true peak.
• Channels: stereo to mono, mono to stereo, swap sides, one side only, or flip the left or right side’s phase.
• Batch of up to 20 files, saved one by one or as a ZIP, as MP3, M4A, OGG, WAV or FLAC.

• Use “Even loudness” for a playlist or a podcast series: peak normalising makes files equally peaky, not equally loud.
• For speech that jumps between quiet and loud, try “Even out” at Medium before normalising; it does more for clarity than extra gain.
• Streaming apps turn loud tracks down to their target anyway, so going louder only adds limiting. Spotify suggests a −2 dBTP ceiling for loud masters.
• If a stereo recording sounds hollow, or almost vanishes in mono, one side is probably wired backwards: flip that side’s phase.
• A boost of more than about 12 dB on a noisy recording raises the hiss too. Try the equaliser’s “Reduce hiss” first.