How do I boost the bass of a song?

Add the song, choose Light, Medium, Heavy, Extreme or Car subwoofer (or drag the slider up to +15 dB), press Play and switch between Original and Boosted to hear the difference, then download the MP3.

Will bass boosting distort my song?

A big bass boost pushes the peaks of a song past full scale, which is what makes it crackle. The anti-clip limiter is on by default and keeps every peak below −1 dB, and the indicator shows No distortion ✓. If you switch the limiter off, it shows Clipping! whenever the boosted sound overloads.

Which bass setting should I choose?

Sub 40 Hz adds deep rumble for subwoofers and car systems, Deep 60 Hz suits most music and earphones, and Punchy 100 Hz makes kick drums hit harder on phone and laptop speakers, which can't play 40 Hz. Medium (+7 dB) is a good start; keep Extreme and Car subwoofer for big speakers.

Is the bass booster free and private?

Yes. It is free with no sign-up and no watermark, and the song is processed inside your browser — nothing is uploaded to a server.

Can I adjust more than the bass?

Yes. Fine-tune in the full Equalizer opens your song with the same bass setting in the 10-band equalizer, where you can also shape mids and treble, use presets like Bollywood or Car, and normalize the loudness.

Free Online Bass Booster

Boost the bass of any song, MP3 or MP4 for free. Choose Light to Extreme, hear it live, download MP3. Runs in your browser – no upload, no sign-up.

Beta: this tool works for common files but is still being improved; see Limitations below.

About Bass Booster

Bass Booster is the Equalizer reduced to its bass controls: one slider from 0 to +15 dB, five intensity presets and a choice of where the boost is centred. A low shelf does the boosting, a subsonic filter removes inaudible rumble, and a limiter keeps peaks below -1 dB, so the boosted song does not crackle.

How to use Bass Booster

Add a song or a video. The boost starts at Medium (+7 dB), so you can press Play and hear it immediately.
Pick Light (+4), Medium (+7), Heavy (+10), Extreme (+13) or Car subwoofer (+15 dB at 40 Hz), or drag the slider.
Choose the Focus: Sub 40 Hz for rumble you feel, Deep 60 Hz for most music, or Punchy 100 Hz for kick drums on small speakers.
Switch between Original and Boosted while it plays. Watch the status badge: it reads limiter working when the limiter is holding peaks down.
Choose MP3, M4A, WAV or the video format, set the bitrate, and download.

When it helps

Songs for a car system

Car subwoofers reproduce 40 Hz well, so the Car subwoofer setting adds weight there. Listen at a moderate level first: a lot of 40 Hz energy can make a door panel rattle long before it sounds loud.

More kick on earphones

Light or Medium at 60 Hz gives most earphones a fuller low end without muddying vocals. Many wireless earbuds already have a bass-heavy tuning, so go lighter there.

Thin-sounding phone recordings

A phone video of a live performance often lacks low end. A modest boost at 100 Hz restores some body, and the video's picture is copied unchanged.

Tips

A bass boost raises peaks, so the limiter has to lower them, which can make heavily boosted songs sound squashed. If it sounds pumping, step down one intensity level.
The shelf is centred an octave above your chosen focus so that most of the boost lands on that frequency and below.
Use Fine-tune in the full Equalizer to carry the same song and bass setting over to the 10-band equalizer, for example to cut a little at 250 Hz if the boost makes things muddy.
192 kbps MP3 is a sensible default; 320 kbps helps little for most listening but costs more space.

Limitations

Speakers that cannot produce 40 Hz will not reproduce Sub boosts no matter how much you add; you will mostly hear the limiter working harder.
Very large boosts on already-loud modern masters leave little room, and the limiter reduces overall punch.
Only the bass is adjustable on this page; mids, treble and loudness normalization are in the Equalizer.

What happens to your files

The song is decoded, boosted, limited and encoded inside your browser; nothing is uploaded. The encoder and media library come from File Studio's own site the first time they are needed. The file you add and the result (when it fits) are kept in the local File Studio workspace in IndexedDB on this device until you delete them.

Related guides

Audio Equalizer Frequency Guide: How to Fix Muddy Vocals, Boomy Bass & Harsh Treble

One Slider From Light to Extreme

Add a song and the bass is already lifted to Medium so you can hear it straight away. Drag the big slider anywhere from 0 to +15 dB, or tap Light, Medium, Heavy, Extreme or Car subwoofer, then flip between Original and Boosted while it plays. An anti-clip limiter is on by default: heavy bass pushes peaks past full scale, and the limiter holds them under −1 dB so the boosted song thumps instead of crackling. The indicator next to it shows No distortion ✓, or Clipping! if you turn the limiter off.

Choose Where the Bass Hits: 40, 60 or 100 Hz

Sub 40 Hz adds the deep rumble you feel from a subwoofer or a car system. Deep 60 Hz suits most songs on earphones and home speakers. Punchy 100 Hz makes kick drums and bass lines cut through on phone and laptop speakers, which physically can't play 40 Hz. A gentle subsonic filter removes the inaudible rumble below the boost, so the extra bass doesn't waste loudness. When you want more control, Fine-tune in the full Equalizer opens the same song and setting in the 10-band equalizer.

Boost Bass in Videos Too — Nothing Uploaded

Download the result as MP3 (192 kbps by default, or 128 / 320), M4A or WAV, with the estimated size shown before you save. Add an MP4, MOV or WebM video and you can download the video itself: the picture is copied untouched and only the sound gets the bass boost. All of it runs in your browser on your own phone or computer — the song is never uploaded, there is no sign-up and no watermark.

Frequently asked questions

How do I boost the bass of a song?: Add the song, choose Light, Medium, Heavy, Extreme or Car subwoofer (or drag the slider up to +15 dB), press Play and switch between Original and Boosted to hear the difference, then download the MP3.
Will bass boosting distort my song?: A big bass boost pushes the peaks of a song past full scale, which is what makes it crackle. The anti-clip limiter is on by default and keeps every peak below −1 dB, and the indicator shows No distortion ✓. If you switch the limiter off, it shows Clipping! whenever the boosted sound overloads.
Which bass setting should I choose?: Sub 40 Hz adds deep rumble for subwoofers and car systems, Deep 60 Hz suits most music and earphones, and Punchy 100 Hz makes kick drums hit harder on phone and laptop speakers, which can't play 40 Hz. Medium (+7 dB) is a good start; keep Extreme and Car subwoofer for big speakers.
Can I boost the bass in an MP4 video?: Yes. Add an MP4, MOV or WebM video and download it as a video: the picture is copied untouched and only the sound is re-encoded with more bass. Or save just the sound as an MP3.
Is the bass booster free and private?: Yes. It is free with no sign-up and no watermark, and the song is processed inside your browser — nothing is uploaded to a server.
Can I adjust more than the bass?: Yes. Fine-tune in the full Equalizer opens your song with the same bass setting in the 10-band equalizer, where you can also shape mids and treble, use presets like Bollywood or Car, and normalize the loudness.

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