Free tool
Volume booster
This volume booster makes audio louder: a call recorded from across the room, a lecture from the back row, a voice memo that’s barely there. Drag the boost, listen to eight seconds, and save. A limiter keeps the loudest moments from clipping.
- Free
- Up to +30 dB, with a limiter
- Nothing is uploaded
Drop your quiet recording here, or Choose your quiet recording
MP3, M4A, WAV, FLAC, OGG, AAC, or the sound of an MP4, MOV or WebM video, up to 1 GB and 2 hours. Everything happens in your browser; nothing is uploaded.
MP3 encoding by LAME, open-source software.
Recordings of calls coming out quiet? NoteOwl records a call on your Mac from the call’s own sound and your microphone separately, so the other side isn’t a faint voice picked up by the room.
How it works
How do you make an audio file louder?
To make audio louder, add the recording. The page reads its loudest peak and proposes a boost; drag the slider to change it, and watch the waveform grow. Keep Prevent clipping on, listen with Listen louder, then press Boost volume and download.
- 1
Add the quiet file
MP3, M4A, WAV, FLAC, OGG or a video’s sound. The page shows its loudest peak in decibels.
- 2
Set the boost
Drag from −12 to +30 dB, or press As loud as it goes without the limiter. The readout says what would be held back.
- 3
Listen, then save
Hear eight seconds from the playhead with the boost applied, then save the whole file as MP3 or WAV.
How much louder can a recording get?
Up to 30 dB, which makes each sample about 30 times larger. One click can normalize a recording: a quiet call peaking at −28.6 dB was raised by 27.5 dB, and came out with its peak at −1.3 dB, as loud as it goes without anything cut off.
Past that point the limiter takes over: the rest of the recording keeps getting louder while the few loudest moments are held just under the top. Every 6 dB doubles the level of the waveform; 10 dB is roughly twice as loud to the ear.
What is clipping, and how does the limiter stop it?
A digital file can’t hold a sound louder than its top level. Boost past it and the tops of the waves are cut flat, which you hear as crackle. The limiter looks five milliseconds ahead and smoothly turns down only what would go over, so it stops at −1 dB.
- The page warned
- Prevent clipping onAbout 11 s held back by the limiter
- Prevent clipping offAbout 7 s would clip
- Loudest peak in the file
- Prevent clipping on−1.2 dB
- Prevent clipping offFull scale, cut flat
- Clipped samples
- Prevent clipping onNone
- Prevent clipping off17,495
| Prevent clipping on | Prevent clipping off | |
|---|---|---|
| The page warned | About 11 s held back by the limiter | About 7 s would clip |
| Loudest peak in the file | −1.2 dB | Full scale, cut flat |
| Clipped samples | None | 17,495 |
Why does boosting a recording make the hiss louder too?
Because the booster raises everything in the file by the same amount: the voice, and the room noise and hiss under it. A noisy recording gets louder without getting clearer. Boost only as much as you need, and listen to the preview at a pause between words.
Can this volume booster make my computer or browser louder?
No. It makes an audio file louder, so the new file plays louder everywhere. It doesn’t change your computer’s volume, another tab or a video playing online. For those, use your computer’s sound settings, or the player’s own volume control.
How do you stop recorded calls from coming out quiet?
Record the call’s sound directly instead of through the room. NoteOwl records calls on your Mac from the call’s own audio and from your microphone, kept separate, with no bot joining. The other side comes through at the call’s level, and NoteOwl then transcribes it with each speaker labelled.
FAQ
Questions about boosting volume
Is my recording uploaded to make it louder?
No. The boost happens inside your browser: it reads the recording from your device, applies the boost and the limiter in the page, and saves the result back to you. No network request was made while we boosted a four-minute call.
What does “As loud as it goes without the limiter” do?
It sets the boost that brings the recording’s loudest moment up to −1 dB, so nothing needs limiting. On a quiet call that was +27.5 dB. If the recording is already near full volume, the button gives a small boost, and you can push further with the limiter on.
Can I hear the result before saving?
Yes. Listen louder plays eight seconds from the playhead with the boost and the limiter applied, exactly as they’ll be in the file. Click the waveform to move the playhead to the part you want to check.
Can I make a recording quieter?
Yes. The slider goes down to −12 dB, for a recording that is too loud or that you want to sit lower beside others. To increase volume instead, drag it the other way, up to +30 dB.
Will the boosted file be bigger?
It depends on the format you save, not on the boost. A small M4A saved as a 192 kbps MP3 grows; a WAV stays the same size as a WAV. A four-minute call came out as a 5.5 MB MP3 at 192 kbps.
Does boosting work on a phone?
Yes. Choose the recording, drag the boost slider with your thumb, and save. On an iPhone the louder file goes to the Downloads folder in the Files app.
Keep exploring
More audio editing tools
- Audio speed changerSpeed up or slow down an audio file from 0.5× to 2× in your browser, keeping the pitch or not, and save it as MP3 or WAV
- Audio trimmerTrim the start and end off a recording in your browser by dragging on its waveform; MP3, M4A, WAV and FLAC are cut without re-encoding
- MP3 cutterCut a clip out of an MP3 or any audio file, with fades, or cut a part out of the middle; saves an MP3 at 128, 192 or 320 kbps
- Audio splitterSplit a long recording into parts in your browser: equal parts, every few minutes or where you choose, each split moved to a pause; no re-encoding
Related
- Mic testA free online mic test: a live level meter, a microphone picker and a 5-second recording to play back, in your browser
- Background noise removerRemove steady background noise (fans, hum, air conditioning, traffic, typing) from a voice recording in your browser with an AI speech model; nothing is uploaded
- Audio to text converterTranscribe audio to text free: drop in an MP3, M4A, WAV or other recording and get an AI transcript with times, as text, SRT, VTT or Word; nothing is stored
- Audio to textTranscription software for your Mac: drop in an audio or video file and get a speaker-labelled transcript with timestamps, unlimited, with nothing uploaded
Calls recorded clearly, notes written on your Mac
Free to download. Runs entirely on your Mac.
macOS 26 or later · Apple Silicon (M1 or newer) · 16 GB memory minimum, 24 GB recommended
About NoteOwl
NoteOwl is private AI meeting notes and memory for the Mac. It captures meetings without a bot joining the call, labels every speaker, writes summaries and action items, and builds a memory of every conversation that you can chat with — fully offline, because the speech recognition and the AI run on the Mac itself. Dictation into any app is free; Pro is a one-time purchase.
NoteOwl pricing: what’s free and what Pro adds
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