Free online audio tools that stay in your browser

What WaveTinker is

WaveTinker is a toolbox for the small audio jobs that come up again and again. A voice memo is too quiet. A song needs to be a little slower for practice. A clip has to be cut to thirty seconds for a ringtone. A track needs a dreamy, slowed-down mood for a video edit. Each of these has its own page with one tool on it, a waveform, a few controls and a download button, so you can finish the job without learning a full audio editor.

The tools fall into three groups. Effects change how a track sounds: volume, bass, slowed + reverb, 8D audio, nightcore, sped-up versions, speed, pitch, reverb and echo, reverse, fades and normalizing. Editing tools cut, join, record and convert. Musician tools measure and help you play: a BPM finder, tap tempo, a key finder, a Camelot wheel, a metronome, three tuners, a chord finder, a tone generator, a mic test and a hearing check.

There are two ways in. The studio at the top of this page builds a sound from several effects at once, and the 30 single-purpose pages below it each do one job. On the effect and editing pages the controls are rotary knobs: drag a knob up or down, press the arrow keys when it has focus, or double-click it to send it back to its default. Result and Original buttons switch between the processed sound and the untouched one at the same moment of the track, and presets give a sensible first position. Under the text on each tool page, tabs named Guide, Questions, Numbers and Patch next keep the explanation, a computed table and related tools one tap away. A few musician tools, such as the metronome tempo and the tone generator frequency and volume, keep ordinary sliders.

The studio: a chain of effects in one place

The studio is a chain. You drop in a file, then build a row of modules, and the audio passes through them from left to right: the card on the far left first, then the next, and so on. Twelve modules are on offer: Speed, Tempo, Pitch, Bass, Bright, Reverb, Echo, 8D, Volume, Loudness, Fade and Reverse. Each button adds one to the row, and the row holds at most eight, which is more than any of the recipes below needs.

Every module is a small card with its own knobs. Speed changes tempo and pitch together, from 50 to 160 percent, like a record played at another speed. Tempo changes only the speed, from 0.5 to 2 times, and Pitch changes only the key, up to 12 semitones either way. Bass lifts the low end by a gain at a chosen frequency, and Bright adds treble above 4 kHz. Reverb has an amount and a decay time, Echo an amount and a delay in milliseconds, and 8D a turn time in seconds and a width. Volume is a plain gain in decibels, Loudness aims at a LUFS target, Fade has a fade in and a fade out, and Reverse plays the file backwards and has no knobs at all.

A card also has four small controls in its header. The round LED bypasses the module without deleting it, which is the quickest way to hear what that step contributes: switch it off, listen, switch it back on. The left and right arrows move the module along the row, and the cross removes it. After any change the preview renders again in about a quarter of a second, and the Result and Original buttons, the space bar and the waveform work exactly as on the single pages.

Why the order of the modules matters

Because the chain runs left to right, the same modules in a different order give a different sound. The clearest case is Speed and Reverb. Put Speed first and the reverb is added to the slowed track, so its tail keeps its real length in seconds. Put Reverb first and the finished tail is slowed along with everything else, so it grows longer and drops in pitch with the music. Neither is wrong, but they are not the same effect.

Level modules like to sit late in the row. Reverb, Echo and Bass all add energy, so a Loudness module placed before them aims at a figure that the later modules then change. Put Loudness after the effects and it measures what you will actually hear. Fade belongs at the very end for a related reason: it then fades the whole result, including any reverb or echo tail the earlier modules added, and the length of the fade is counted from the true end of the file.

The Reverse module can work as a sandwich. Reverse the track, add reverb, reverse it again, and the reverb tail ends up in front of each sound instead of behind it. Leave out one Reverse and you simply get a backwards track with some reverb on it.

A limiter always closes the chain. It cannot be removed or moved, and it holds peaks at -1 dBFS, so stacking Bass, Volume and Reverb does not clip the saved file. It is a safety net rather than a fix: if a combination pushes hard against it, drums lose their snap, so lower a gain instead of asking the limiter to absorb the excess. Bypassing modules one at a time with their LEDs shows which one is pushing.

The six recipes and what is inside them

Recipes are ready-made rows that give you a starting point. Pressing one replaces the current row, so copy a link to your own chain first if you want to keep it. The studio opens with the first recipe loaded.

Slowed + reverb is Speed at 85 percent, Reverb at 45 percent with a 3 second decay, and Bass at +2 dB around 100 Hz. Nightcore is Speed at 125 percent with Bright at +2 dB and Bass at +2 dB. 8D slowed is Speed at 90 percent, a light Reverb at 25 percent with a 2 second decay, and 8D with a turn of about 8 seconds at 90 percent width, so it wants headphones. Vaporwave is Speed at 80 percent, Reverb at 50 percent with a long 4.5 second decay, and a soft Echo at 25 percent with a 450 millisecond delay.

Reverse reverb is Reverse, then Reverb at 60 percent with a 3 second decay, then Reverse again, which produces the swell that builds into each sound. Podcast polish is a different kind of recipe, made for speech: Loudness aimed at -16 LUFS, followed by a short Fade of 0.3 seconds in and 1.5 seconds out.

Treat every recipe as a first draft. The point of the studio is that you can turn one knob, bypass a module you do not need, or drop in another one, and hear the result straight away.

Sharing a chain, saving and carrying on

The Copy settings link button puts the whole chain into the page address after a hash: the modules in order, with the value of each knob. Whoever opens that address gets the same row and the same knob positions, and then adds their own file. The audio is never part of the link. A module you have bypassed with its LED is left out of the link, so what you share is exactly what you hear. You can also bookmark the address to return to a chain later.

When the chain sounds right, choose MP3 (128, 192, 256 or 320 kbps) or WAV (16-bit or 24-bit), glance at the estimated size and download. The studio opens on MP3 at 192 kbps, and the saved name is your file name with the word chain added at the end. Under the player, Continue with the result in offers the audio trimmer, the audio converter and the normalizer, which take the processed audio through your browser's own storage when it still needs cutting, converting or a loudness check.

Long chains on long files take longer, because the modules render one after another and any knob change starts the work again. A track over five minutes shows a notice that processing can take a minute. While you experiment, keep the clip short: trim it first with the audio trimmer, then bring the trimmed file back to the studio.

When a single tool is the better choice

The studio chains effects; it does not replace the single pages. Open a single page when you need something the studio leaves out. The trimmer, joiner, converter and voice recorder are separate tools, as are the analysis and music tools. The audio speed changer reaches 0.25 to 4 times and has a switch for keeping the pitch, while the studio's Speed module stops at 50 to 160 percent and its Tempo module at 0.5 to 2 times. The normalizer can aim at a peak level as well as at loudness, and the studio's Loudness module works in LUFS only. The fade page offers three curves, and the studio always uses the equal power one.

The single pages also show readouts that the studio does not: the peak and loudness of the result on the volume and bass boosters, and the before-and-after figures on the normalizer. Each page has presets tuned for its job, a guide that explains the reasoning behind each setting, and a Numbers tab with a computed table. If you want to learn what a knob does, or you only need one change, a single page is quicker and easier to read. If you notice yourself pressing Continue with the result in for the third time, move to the studio.

How in-browser processing works

When you pick a file, your browser reads it from your disk and decodes it into raw samples, the long list of numbers that describes the waveform. The effect is then applied to those numbers by code running on your own computer or phone. When you press Download, the finished samples are encoded into an MP3 or WAV file and handed straight to your downloads folder. At no step does the audio travel to a server, which is why there is no upload bar, no queue and no waiting for someone else's machine.

There are practical consequences. Speed depends on your device rather than on our traffic, so a short clip finishes almost instantly on a laptop and a little slower on an older phone. A file you drop in stays private even on a slow connection. And because your files are not stored on a server, there is no copy for us to delete later. After your first visit the site can be installed as an app from the browser menu, and pages you have opened keep working offline.

Turning a knob re-processes the audio in about a quarter of a second, which is why you can tune an effect by ear instead of guessing. The last file you opened is kept in this browser's storage on this device so the next tool can offer to continue with it, and clearing the site data removes it. Files up to 250 MB are accepted, and the format list covers whatever your browser can decode: MP3, WAV, M4A and AAC, OGG and Opus, and FLAC. A video works as a source as well: drop an MP4, MOV or WebM file on the studio or on any effect or editing page and its sound track is used, and what you save is audio.

Passing a result from page to page

The most useful habit on the site is passing a result from one tool to the next. Under each effect and editing tool you will find links labeled Continue with the result in. Pressing one carries the processed audio, not the original, into the next page, using the browser's own storage on your device. You never have to save an intermediate file and open it again.

Example one is a prep session for a DJ set or a remix. Run the file through the BPM finder to get its tempo, then the key finder for the key and its Camelot code. Open the Camelot wheel to see which neighboring keys mix cleanly with it, and if your next track sits a step away, use the pitch changer to nudge this one by a semitone or two so the keys agree. If the tempos differ, the speed changer can close the gap while keeping the pitch where it is.

Example two is cleanup. Boost a quiet interview with the volume booster, normalize it to a podcast loudness target, trim the dead air from both ends, and convert the result to a compact MP3. Each step is a separate decision with its own controls, which keeps the process easy to redo: keep your original file and start again from any page.

A mood edit for a short video used to take four pages. Now the Slowed + reverb recipe in the studio does the same job in one place, with a Fade module at the end so the clip begins and ends cleanly, and the final download happens once.

Picking the right tool for a common job

If the file is too quiet, start with the volume booster; it raises everything by a set number of decibels and can hold peaks back with a limiter. If it is quiet compared with other tracks and you want a consistent level, the normalizer measures loudness and aims at a target such as the one streaming services use. If the music feels thin, the bass booster adds low end without touching the volume control's job.

For tempo and pitch edits, the choice depends on what should move. The slowed + reverb tool drops tempo and pitch together and adds space. The sped-up and nightcore tools raise both. The speed changer covers anything from a quarter speed to four times and can keep the pitch fixed, which suits transcribing a solo. The pitch changer does the reverse and keeps the tempo fixed, which suits singing a song in a better key.

For cutting and packaging, the trimmer takes a section out of a file, the joiner stacks several files with optional crossfades, and the converter saves any readable file as MP3 or WAV. If you only need that one conversion, the WAV to MP3 and MP3 to WAV pages open with sensible defaults already chosen. To capture something new, the voice recorder uses your microphone and hands the take to the trimmer view.

For practice and music theory, use the tuners for strings, the metronome for time, and the BPM, key and chord tools for working out what a piece is made of. For equipment questions, the mic test shows whether your microphone is alive and how loud it is, and the hearing check lets you explore what your headphones and ears reproduce at the edges of the range.

For musicians, DJs and teachers

Practice is where the tools earn their keep. Slow a passage to 75 percent without changing its pitch, concentrate on the difficult bar, and raise the speed in small steps as it settles. Tune the instrument first with the guitar, ukulele or chromatic tuner; they listen through the microphone, show the needle in cents, and tell you whether to tune up or down. Then set the metronome to the tempo that the BPM finder or tap tempo gave you.

Singers and horn players can transpose. The pitch changer shifts a backing track by semitones, and the chromatic tuner has an instrument-key setting that shows the written note for B-flat, E-flat and F instruments. The chord finder helps when you know the notes under your fingers but not the name of the shape, and it lists scales that contain them, which is a decent starting point for improvising.

DJs and producers get the tempo, key, Camelot code and compatible moves in one chain. Teachers can use the tone generator for ear-training exercises and the metronome with accents and subdivisions for rhythm lessons. When you play loudly in headphones, keep the level moderate and take breaks, since long exposure to loud sound can damage hearing.

Honest limits

Analysis is an estimate. The BPM finder looks at the pulse in the middle of a file and may report half or double the tempo you feel, which is why it shows both. The key finder compares the notes it hears with typical major and minor patterns, and it most often confuses a key with its relative major or minor. Treat both as a strong hint and confirm by ear. The tuners and the loudness measurements follow published methods, but they are still estimates and depend on your microphone and your speakers.

A long chain is also a stack of small approximations. The Tempo and Pitch modules re-synthesize the audio, so two or three of them in a row sound more processed than one. For the classic slowed or sped-up sound, a single Speed module only changes the playback rate and adds no stretching artifacts. Use the stretching modules only when you really need tempo or key to move on their own.

Very long files can be slow. Decoding and re-encoding an hour of audio is heavy work, and an older phone may take a while or run short of memory. If a device struggles, trim the file first or process it on a computer. Saving as MP3 also re-encodes the sound, so repeated exports cost a little quality each time; keep a WAV while you are still editing.

Some things are outside what WaveTinker does. There is no stem separation, so you cannot pull a vocal out of a finished mix, and there is no AI noise removal. The converter writes MP3 and WAV only, not FLAC, OGG or M4A files. And the site does not fetch audio from streaming services or web addresses: it works with files you already have, which you should only edit when you own them or have the right to use them.