Start tuning
- (Browser only) Allow microphone access: Tap to Tune
- Play a note on your instrument
- Adjust while watching the display, until the rings are as stationary as practical
What is a strobe tuner?
A strobe tuner compares your instrument's tone against a steady internal reference and shows the difference as motion. StroboPro draws that comparison as several harmonic rings at once, so you see the whole note, not just one part of it. It works for guitar, bass, piano, strings, winds, and more.
StroboPro has <0.1 cent display resolution. Within about 25 cents of the target pitch, the rings settle enough to show changes smaller than a tenth of a cent. The default Velocity mode keeps the motion smooth and readable, without the flicker of an old mechanical strobe.
Learn more: read our guide to professional strobe tuners for how they work and what to look for.
For deep dives on strobe tuning, <0.1 cent resolution, bass and piano tuning, and how to test any tuner's accuracy, visit the StroboPro Blog.
How to read the StroboPro display
Fundamental and harmonics
Most instruments produce not just a single tone but a fundamental plus a series of harmonics above it. StroboPro shows these as individual harmonic rings around the display:
- The innermost ring is the fundamental
- Each outer ring is the next harmonic (a multiple of the fundamental)
- A brighter ring means a stronger harmonic in your instrument's sound
- You choose how many rings to show, from 4 up to 10, under Settings (Visible Harmonics). The default is 4. This only changes what you see; tuning accuracy is unaffected, and the cents reading always comes from the fundamental and the first few harmonics no matter how many rings are shown
Speed and direction
The motion of the rings tells you how close you are:
- In tune: the rings stand still
- Drifting clockwise (top moving right): the note is sharp
- Drifting counter-clockwise (top moving left): the note is flat
- How fast the rings spin shows how far off the pitch is
Getting every ring perfectly still is nearly impossible at this precision. Center Assist (free) highlights the center of the display when you are inside a narrow band around the target. It is only a visual aid: it does not change what counts as in tune, and it does not stop the rings.
Ring brightness
Each ring's brightness follows the strength of that harmonic in your instrument's sound. The scaling is compressed rather than a straight line, so use brightness to compare harmonics against each other, not to measure them. How bright a ring appears also depends partly on your microphone.
Cents and frequency display
Alongside the rings you get three numbers:
- The note name being detected
- Cents deviation from that note, shown on the LED bar across ±58 cents
- The detected frequency in Hz
The cents readout is smoothed separately from the ring motion. Both come from the same detection engine, so small differences between the two are normal. The cents number always comes from the strongest of the fundamental and its first three harmonics, no matter how many rings are visible. For the most precise tuning, trust the rings.
Learn more: see how StroboPro achieves <0.1 cent resolution.
Using Note Lock and Pitch Pipe
Note Lock and Pitch Pipe live in the same compact control. In its default state, press or click the control to open it and reveal the options.
Note Lock focuses the tuner on your selected note and narrows the frequency range so that note's harmonics display cleanly.
How Note Lock works
When you enable Note Lock (on mobile, tap the note name to toggle it):
- The tuner applies targeted audio filters around your selected note and optimizes the frequency range so its harmonics display cleanly
- It becomes easier to tune that specific note without jumping to other notes
- It helps in noisy environments and with instruments that produce complex harmonics
- It automatically adjusts the frequency range so high harmonics of high notes stay visible
Note Lock is a filtering aid, not forced detection:
- If you play a completely different note than the one selected, StroboPro may still detect that note, or it may report the selected note as correct, because the filtering is quite strong
- Note Lock simply stabilizes detection when you are playing close to the selected note
- Think of it as focusing the tuner's attention, not restricting its detection
When to use Note Lock
- Tuning in noisy environments (backstage, band practice)
- Instruments with complex overtones, like pianos or some wind instruments
- Working methodically through each string or note
- When StroboPro keeps jumping off the correct note
Prev / next note navigation
When a note is locked, use the on-screen left and right arrow buttons to step through adjacent notes without unlocking. Left locks to the previous (lower) note, right to the next (higher) note.
Tune string by string: lock the first string, then tap the right arrow to advance to the next note without re-locking manually.
When not to use Note Lock
- When you need to quickly tune several different notes
- If you are unsure which note you are tuning toward
- When you want to see what note you are actually playing
Pitch Pipe FREE
Reference tones generated in real time, with smooth fade in and out so tones start and stop silently: no clicks or pops during performances. Ideal for a cappella groups, choir directors, and anyone who needs a reliable reference pitch.
- Press or click the Note Lock and Pitch Pipe control to open it
- Select the Pitch Pipe option and choose the note you want to hear
- Adjust the amplitude to suit your environment
- Press or click the note again to stop (the smooth fade-out prevents clicks)
Fine-tune with microphone sensitivity
You can set microphone sensitivity (dB) in Advanced settings to suit your instrument and environment. This helps StroboPro lock onto the notes you play without interference from ambient sound.
The vertical bar is the trigger level. StroboPro adjusts it automatically to match the background noise. When the incoming signal rises above that level, pitch analysis starts. You can press or click the bar to adjust the sensitivity manually.
If detection is unreliable:
- Move to a quieter location if possible
- Position your device's microphone closer to the instrument
- Play notes clearly and let them sustain
- Adjust sensitivity by pressing on the VU meter (pictured above)
Customizing your tuning setup
Reference frequency
The default reference is A4 = 440 Hz. Change it in settings:
- To match other musicians who use a different reference
- For historical or period instruments that traditionally use other references
- For personal preference or specific performance requirements
Your chosen reference frequency is saved for your next session.
Transposition
Transposition shifts the note names shown on screen. It is useful for transposing instruments, whose written pitch differs from the pitch that actually sounds. When you set a transposition, StroboPro shows the note as it would be written on the score rather than the sounding note.
Example: a B♭ clarinet playing a written C sounds a B♭. Setting the transposition to C to B♭ makes the tuner show the written note (C) instead of the sounding note (B♭).
Set it via the transposition chooser in settings. It applies globally, to all tuning modes.
Transposition with custom or AI tunings: the note name shifts to the written pitch while the frequency (Hz) stays at the true sounding pitch. A note label and an Hz value that belong to different letter names is intentional, and in tune still measures the true pitch.
Built-in chromatic tunings handle transposition differently: they shift the tuning reference. This is expected.
Note names use standard letters (A through G with ♯/♭). Custom display symbols you set per note are not changed by transposition: a symbol is a positional label (a string number, a key name, a paired-course marker), not a pitch name, so it stays attached to its note. See Display symbols below.
Display symbols (custom note labels)
Every note in a tuning can carry an optional display symbol: a short label that replaces the standard letter name wherever the note is shown. Set it per note in the tuning editor (Edit Note, then Display Symbol). Leave it blank to keep the standard note name.
When a note has a symbol, it appears in place of the letter name in the note-lock chips along the side of the display and in the main note readout at the center.
Common uses:
- Stringed instruments: number the strings (1 to 6 for guitar, 1 to 4 for bass) so each chip names the string rather than its pitch
- 12-string and paired courses: mark paired strings with labels like "4+3" or "2+1" to tell the courses apart
- Custom or experimental tunings: any short label (a key name, a sympathetic-string name, an arbitrary tag) that matches how you think about the instrument
A display symbol can be a positional label, a pitch, or anything else. Transposition shifts the underlying pitch (and the standard letter name a note would show), but the symbol itself never changes. A bass labeled 1 to 4 keeps those numbers on the same strings whether or not you transpose; only the pitch each string is tuned to moves. The in-tune measurement is always against the true sounded pitch.
Instruments and tunings
- Select your instrument type from the dropdown
- Choose from tuning presets for that instrument
- Each instrument includes special offsets for accurate tuning
Some tunings (piano stretch, True Temperament) include per-note cents offsets baked into the tuning definition.
Save your tuning work across devices FREE
Sign in to keep your personal tuning library available on web, iOS, and Android: your custom instruments and tunings, and your reference frequency preference.
Custom tunings you create while signed out are stored only on that device and will not sync. Sign in before creating them to keep them everywhere. Signing out returns the app to its default instrument set; your synced tunings reload automatically the next time you sign in.
Record mode: create custom tunings FREE
- Select "Add Instrument" and enable Record mode
- Play each string or note of your instrument one at a time
- StroboPro detects and saves each note automatically
- Name and save your custom instrument tuning
When you create a new custom tuning, StroboPro inherits the notes from the first existing tuning under the same instrument and sub-instrument combination, as a baseline starting point. If the category is empty, it starts from a single reference note (A4), which you can customize or hand to AI generation.
Account and devices
Your StroboPro account is what keeps your tuning library and Pro access together. Your name or email address is not used to match purchases; sign in to the same StroboPro account instead.
- Open Account → Sign-in methods while signed in on the web
- Link Apple, Google, or passwordless email
- Use any linked method on web, iOS, or Android to return to the same library and Pro access
Already bought Pro? Update StroboPro, sign in to the same StroboPro account, and use Restore Pro Access in Settings if access does not appear. If that does not resolve it, contact support@applicaudia.se.
Signed-out Pro access: paying native customers keep local Pro access on their purchase device when signed out. Cloud library sync, cloud backup, and AI generation require signing in. If you reinstall or switch devices, use Restore Pro Access or sign in to your original account.
Piano Tuning Assistant PRO
The Piano Tuning Assistant (PTA) is a guided Pro tool that builds a tuning tailored to your specific piano. Every piano is a little different; the thickness and length of its strings affect how the notes sound together. The PTA listens to your piano, learns how its strings behave, and builds a tuning that makes your piano sound its best.
Why pianos need special tuning
On most instruments, a tuned note has overtones that line up neatly with other notes. Piano strings are thick and stiff, which pushes their overtones slightly sharp (inharmonicity), especially in the bass and the highest treble.
Tune a piano to a plain chromatic setting and chords will clash. Professional piano tuners solve this by stretching the tuning: high notes a bit sharp, low notes a bit flat, so the piano sounds in tune with itself. The PTA does this automatically, from measurements of your actual piano.
Using the Piano Tuning Assistant
For the full walkthrough, see our piano tuner guide.
If a note's row stays on "Waiting for note…" during measurement, the note is probably far from its target pitch - so far that the tuner hears it as a different note. Switch back to the chromatic tuner, play the note, and read which note name and cents it shows. If it is more than roughly a semitone off (or shows the wrong note name), tune it closer first with the chromatic display, then return to the measuring step. Very out-of-tune pianos are easiest to rough-tune chromatically first and measure afterwards.
Predefined piano presets
Don't want to measure? StroboPro includes ready-made stretch presets for common piano types: Spinet, Console, Upright, and several Grand sizes. Each preset carries baked-in stretch data for every note, so the display and detection are optimized for that piano type from the moment you start.
For acoustic pianos, the Mixed 6:3 / 4:2 octave style is highly recommended. It aligns the wider bass octaves for a rich, clear bass, and switches to cleaner octave alignment in the middle and treble so octaves don't beat.
The stretch model belongs to the piano type (the sub-instrument), not to the individual cents preset. When you use Save As, the cents are copied to the new tuning, but the stretch model comes from whichever destination piano type you select. A newly created custom type has no stretch model of its own: pick an existing factory piano type, or measure your piano with the Piano Tuning Assistant to create a custom profile.
Known limitation: the factory stretch models for smaller pianos (Upright, Console, Spinet) produce more stretch than reference data from measured pianos. The Concert Grand and Studio Grand presets are accurate. For smaller pianos, measuring with the Piano Tuning Assistant gives significantly better results than the factory presets.
How the display adapts to your piano
When a piano tuning is active (measured or preset), StroboPro aligns each harmonic ring to where that piano's overtones actually sit, instead of ideal mathematical positions. The display reads clean and steady across all partials, in chromatic mode and with Note Lock alike. No extra steps needed.
DAW plugin (VST3 / AU, public beta)
The StroboPro DAW plugin brings multi-harmonic strobe tuning into your digital audio workstation. Download the public beta from strobopro.se/daw/release/. The plugin is free to download during the beta; premium features unlock with DAW Platform Pro (lifetime) or Universal Pro.
Installation
macOS VST3: unzip the download and copy StroboPro Plugin.vst3 to /Library/Audio/Plug-Ins/VST3/ (or ~/Library/Audio/Plug-Ins/VST3/ for a user-only install), then restart your DAW or rescan plugins.
macOS AU: copy StroboPro Plugin.component to /Library/Audio/Plug-Ins/Components/, then restart your DAW (for example Logic Pro).
Linux VST3: extract the archive with tar -xzf into ~/.vst3/ (or /usr/lib/vst3/ for a system-wide install).
Windows VST3: unzip the download and copy StroboPro Plugin.vst3 to C:\Program Files\Common Files\VST3\, then restart your DAW or rescan plugins.
Standalone: drag StroboPro Plugin.app to /Applications on macOS, run the extracted binary on Linux, or on Windows unzip StroboPro_Plugin_Standalone_win.zip and run the extracted exe.
Gatekeeper and code signing
macOS release downloads are Developer ID signed and notarized, and should open without warnings. If macOS still warns on first launch, right-click the app and choose Open. Windows and Linux builds are unsigned. For the Windows Standalone exe, choose More info and then Run anyway if Windows SmartScreen warns on first launch.
Beta support
For beta support, discussion, and bug reports, visit r/strobopro.
Advanced topics
Intonation adjustment
Intonation is how well your instrument plays in tune across its entire range. For the full process of checking and adjusting intonation on guitars and other stringed instruments, see our intonation tuner guide.
Ensemble tuning
When tuning several instruments to play together:
- Establish a reference: choose one well-tuned instrument as the ensemble reference
- Match reference frequency: make sure every StroboPro instance uses the same reference frequency (for example A4 = 442 Hz)
- Tune in order: bass instruments first, then mid-range, then high
- Check intervals: play octaves and fifths between instruments and make sure they sound consonant
- Final check: play a simple chord progression with everyone to confirm the ensemble tuning
Frequency range
StroboPro chooses how much of the frequency spectrum to analyze, to get the best resolution where it matters. When Note Lock is active, the app picks the range automatically from the locked note and the number of rings you have set under Visible Harmonics. The tuning range extends down to A-1 at 13.75 Hz: the bundled Ultra-Low A-1-G4 tuning enables ultra-low mode automatically, so you can analyze 32-foot organ stops and sub bass notes (on the deepest notes, give the reading a few seconds to settle). See the ultra-low tuner guide for how that works.
- Default: best frequency resolution for bass, guitar, and most stringed instruments. Very high overtones (like the top notes of a piano) are not shown, though their fundamentals are
- Higher: extends the display for instruments with higher harmonics (violins, high guitar registers), with slightly reduced resolution and responsiveness in the extreme bass
- Highest: covers the entire spectrum for very high notes, at the cost of resolution for low pitches: worse for bass guitars and the low strings of a standard guitar
Interplay with Visible Harmonics: when you turn on Note Lock, StroboPro calculates the frequency of your highest visible ring (locked note frequency times the number of visible rings). If those overtones exceed the current range, the app automatically raises the range so all your rings can display cleanly. Locking a high note like E6 with 10 visible rings, for example, boosts the tuner to its Highest range.
FFT Size PRO
FFT size controls the trade-off between note-detection accuracy and responsiveness. Larger sizes identify the note more accurately but with more latency; smaller sizes are faster but less accurate. If StroboPro misidentifies the note you are playing, try a different size. The default is 2048.
The FFT only decides which note you are playing. The tuning itself is measured from the motion of the rings, so FFT size never affects your cents reading.
- 1024: fastest, least precise
- 2048: balanced (default)
- 4096: most accurate, highest latency
Strobe display type PRO
Chooses how the rings are animated. Velocity (default) animates the rings smoothly at whatever frame rate your device sustains, and shows two bright segments on every ring. Position (mobile only) snaps each ring to the measured position, more like a real strobe tuner, and needs a faster device; its ring patterns repeat in proportion to the harmonic number, so higher rings show more repetitions around the circle.
Strobe refresh rate PRO
Controls how often the app measures the ring motion. The rings run continuously; the refresh rate sets how quickly the animation follows changes. Higher rates respond faster but may reduce precision; lower rates are more stable. The default is 80 Hz.
- 30 / 40 Hz: most stable, least responsive
- 60 / 80 Hz: balanced (80 is default)
- 100 / 120 Hz: most responsive, may reduce precision
Glow effects MOBILE
A purely cosmetic toggle that adds a soft glow to the ring display. It is not a premium feature, but it may slow the app down on older devices; turn it off if the animation feels sluggish. Off by default.
Tuning in noisy environments
- Use Note Lock: lock to your target note to reduce note-jumping
- Position your device: place it close to your instrument's sound source
- Isolate your instrument: find a quieter corner, or use your body to shield the microphone from other sounds
- Sustain notes longer: let each note ring out clearly for better detection
Troubleshooting
| Issue | What to try |
|---|---|
| No sound detected |
|
| Display jumps between notes |
|
| App crashes or freezes |
|
| Tuning seems inaccurate |
|
| Custom tunings or Pro access missing on another device |
|
Frequently asked questions
How do I use StroboPro strobe tuner?
Allow microphone access, select your instrument, and play a note. When the harmonic-ring pattern is stationary, you are in tune.
Why is my tuner not hearing anything?
Make sure you have allowed microphone access. If you use a Bluetooth headset, try disconnecting it. Restarting your browser, or switching to Chrome or Firefox, also helps.
What is a strobe tuner and why is it more accurate?
A strobe tuner compares your signal against a stable reference. StroboPro's multi-harmonic display has <0.1 cent resolution, so small pitch changes stay visible.
Is StroboPro free?
Yes. The core tuner, the manual tuning library, and cross-device sync are free when you sign in. Pro unlocks advanced tools such as AI tuning, Position mode, the Piano Tuning Assistant, and more harmonic rings.
What instruments does StroboPro support?
Guitar, bass guitar (4 to 6 string), mandolin, upright bass, piano, ukulele, banjo, nyckelharpa, violin, and any other instrument via custom, user-defined, or AI-generated tunings. You can share your tunings with others via the share button.
Is StroboPro available on iOS and Android?
Yes, on web, iOS, and Android. Each surface offers Platform Pro for that platform, while Universal Pro unlocks the complete Pro toolset across all three.
What is the Piano Tuning Assistant?
A Pro tool that listens to your piano and builds a custom stretch tuning, so chords sound in tune with themselves across the whole keyboard.
How do I use the same account on every device?
On the web, open Account → Sign-in methods while signed in and link Apple, Google, or passwordless email. Then use any linked method on web, iOS, or Android.
What is the difference between Platform Pro and Universal Pro?
Platform Pro unlocks the complete Pro toolset on one named surface: web, iOS, or Android. You can buy it without signing in for use on that platform, with optional account linking and restore later. Universal Pro unlocks the same toolset on every surface and requires signing in to the same StroboPro account across devices.
How can I combine a reference stretch with my piano type?
- Select Piano → Reference Stretches and choose the curve you want
- Select Edit Tuning, then Save As
- Choose Piano and an existing destination type, such as Concert Grand, Studio Grand, Upright, or Spinet
- Enter a unique tuning name and save
- Select the saved tuning under that piano type
Save As copies the reference cents, while the destination piano type supplies its own per-note stretch model. A newly created type has no stretch model of its own, so choose an existing factory piano type or a Piano Tuning Assistant profile. Factory stretch models are generalized approximations; for an actual piano, measuring the real strings with the Piano Tuning Assistant gives a significantly better result.
Pro access and supporting independent development
I keep the core tuner, the manual tuning library, and cross-device sync free. Pro supports the advanced tools and the ongoing work that keeps StroboPro useful and accurate.
Platform Pro
The complete Pro toolset on one named surface: web, iOS, or Android. Buy it without signing in for use on that platform, with optional account linking and restore later.
Universal Pro
The same complete Pro toolset on every surface, when you sign in to the same StroboPro account. Works across every device and surface.
Pro includes AI tuning, Position mode, FFT size, strobe refresh rate, adaptive high-frequency handling, the Piano Tuning Assistant, Echo Mode, and adjustment beyond four harmonic rings. A Universal Pro trial may be available before purchase.
Pro tools
AI Tuning, Echo Mode, and the Piano Tuning Assistant are Pro tools on web, iOS, and Android. The pitch pipe stays free.
AI Tuning generation PRO
Describe any setup in plain words, from "Drop D tuning" and "Open G" to "custom 7-string for death metal", and the AI generates the tuning for you. No manual entry: describe it, then fine-tune or ask for changes.
- Any standard or alternative tuning (Drop D, Open G, DADGAD, and so on)
- True Temperament tunings
- Custom instruments and exotic tunings
- Anything else you can describe; you can always modify the result or ask for changes
AI Tuning is a Pro tool on web, iOS, and Android. Defining and saving manual custom tunings is free.
Echo Mode (accessibility) PRO
Echo Mode provides audio-first tuning guidance for visually impaired users. Instead of reading the ring display, you hear a reference tone that guides you to the correct pitch.
- Enable Echo Mode in Settings
- The app listens continuously for your instrument
- When a stable pitch is detected, it plays a tone that glides from your instrument's pitch to the target pitch
- The tone holds at the target pitch, then fades out
- After a brief hold-off pause (so the app does not hear its own tone), the cycle repeats automatically
- Tune to match the held tone; the cycle keeps guiding you until you stop Echo Mode
Echo Mode uses sensible default durations (minimum note, glide, hold, hold-off) tuned for typical use.
- Echo Mode automatically finds the nearest note to guide you to
- The glide range is limited to ±100 cents; if your instrument is further off, play closer to the desired note
- The hold-off period keeps the app from hearing its own reference tone
- Screen reader announcements are provided for status changes
Get StroboPro on iOS and Android
