# OnlyPure Piano Tuner — No pre-measurement needed

> Professional piano tuning app with advanced temperaments and inharmonicity compensation. (iPhone/iPad app by Patrick Sebastian Stopper.)

- Source: https://appshunter.io/ios/app/onlypure-piano-tuner/id1635946378 (this page in markdown: same URL + `.md`)
- Developer: [Patrick Sebastian Stopper](https://appshunter.io/developer/1635946380)
- Category: Music, Utilities
- Price: Free with in-app purchases
- Rating: 4.50/5 from 2 App Store ratings · 6 written reviews indexed
- Age rating: 4+
- Requires: iOS 16.6 · 16 MB
- Languages: American English, French (France), German (Germany), Italian, Polish, European Spanish
- Released: 2022-09-29
- Data updated: 2026-08-24
- Monetization: freemium
- User reviews in markdown: https://appshunter.io/ios/app/onlypure-piano-tuner/id1635946378/reviews.md

## What is OnlyPure Piano Tuner?

TUNIC OnlyPure is professional piano tuning software, trusted on concert stages worldwide since 2008 — for piano tuners and concert technicians who demand the highest tonal purity and dependable feedback. It is based on equal temperament tuning using acoustically pure duodecimes (octave + fifth), developed by German master piano maker Bernhard Stopper.

PRECISE TUNING WITHOUT PRE-MEASUREMENT
OnlyPure processes piano nonlinearity — inharmonicity, stiffness and damping — automatically during the tuning process. There is no need to measure stretch curves in advance.

STABLE UNISONS
OnlyPure reveals even the slightest discrepancies within a unison. Tune string by string and set the pin with the smallest of movements — the stability you gain stays with the instrument.

EDITIONS

Free demo — permanent, no time limit
• 29 of the 88 keys: C3–C5 plus A0, A1, A6 and C8
• Manual note switching, one instrument of your own in the catalogue
• Stretch options and historical temperaments as a session preview
• For evaluating an instrument, not for tuning one end to end

Basic — one-time purchase, permanent licence
• All 88 keys, manual note switching

Premium — monthly or yearly subscription
• Automatic note detection and chromatic pitch advance
• All stretch options, historical and custom temperaments
• Unlimited instrument catalogue including per-instrument recordings
• Multi-microphone analysis

Reference pitch, display smoothing, backup and the ten-chapter manual with its guided introduction are included in every edition. Note memory, tuning targets and recordings belong to Premium — the demo lets you try them within its key range.

VARIOUS TUNING SYSTEMS (subscription)
The tuning menu brings equal, historical and custom temperaments together in three sections. Alongside pure twelfths: pure octaves, pure fifths, Pythagorean Half/Half and Pythagorean Inverted. For early music: Pythagorean, quarter- and sixth-comma meantone, Werckmeister III, Kellner (Bach), Kirnberger II and III, Vallotti and Young II. Plus a temperament catalogue: any number of custom temperaments, named and stored permanently.

BUILT FOR WORK ON CUSTOMER INSTRUMENTS (subscription)
Save the instruments you look after for years. In the instrument catalogue every piano has its own entry: customer, maker and model, along with temperament, preferred concert pitch and your own tuning targets. Large collections stay manageable — a list with folders, an A–Z rail and search. At the next appointment you load the instrument and carry on in its familiar frame of reference.

NOTE DETECTION AND DISPLAY
Automatic note detection with chromatic advance follows your workflow. Use the automatic mode in quiet surroundings and on moderately out-of-tune instruments. You can always switch notes yourself — with a swipe across the screen.

MULTIPLE MICROPHONES FOR STEADIER READINGS (subscription)
On compatible devices two microphones are analysed separately and combined per partial. This can contribute to steadier readings, especially in the treble.

HARMONIC EQUIVALENT PITCH
Piano strings are inharmonic; OnlyPure therefore works with a harmonic equivalent pitch by default. Compared with fundamental-based tuners, deviations of 2–3 cents sharp (about 0.5–0.8 Hz at A4) are normal. If you need the fundamental as your reference, a single tap in the concert-pitch dialog switches over.

BACKUP
Save your instrument catalogue, temperament catalogue and settings to your iCloud Drive — visible in the Files app, folder “OnlyPure”. Alternatively, pass the backup on as a file, e.g. by email. Recordings are backed up separately.

TERMS OF USE: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

## Key features

- Professional piano tuning
- Stopper temperament support
- Automatic inharmonicity compensation
- Outstanding unison purity
- Multiple temperaments (subscription)
- Calibration for concert pitch (subscription)

## Pricing and in-app purchases

Base price: Free.

**Subscriptions**

| Subscription | Price | Period |
| --- | --- | --- |
| only:pure Basic | $3.99 | per month |
| only:pure Basic | $44.99 | per year |
| OnlyPure Premium | $7.99 | per month |
| OnlyPure Premium - annual plan | $69.99 | per year |

**One-time purchases**

| Purchase | Price | Type |
| --- | --- | --- |
| OnlyPure Basic - One-time purchase | $149.00 | one-time |
| only:pure | $499.00 | one-time |


## Recent user reviews (6 of 6)

All indexed reviews: https://appshunter.io/ios/app/onlypure-piano-tuner/id1635946378/reviews.md

### 5/5 — Eine sehr gute Software

*2026-07-27*

Arbeite schon seit 2008 mit ihr und sie wird immer besser nur im tiefen bass und im hohen diskant zeigt sie kleine Probleme nimmt nicht den Ton richtig auf.Meine Kunden sind mit meinen Stimmungen sehr zufrieden

### 5/5 — Eine sehr gute Software

*2026-05-21*

Arbeite schon seit 2008 mit ihr und sie wird immer besser nur im tiefen bass und im hohen diskant zeigt sie kleine Probleme nimmt nicht den Ton richtig auf.Meine Kunden sind mit meinen Stimmungen sehr zufrieden

### 5/5 — Die führende Stimm-App

*2026-01-12*

Als professioneller Klavierstimmer und Nutzer der ersten Stunde (2007) bin ich bis heute von Only Pure überzeugt, seit mich das  klare, ruhige und warme Klangbild begeistert hat, basierend auf reinen Duodezimen (Oktave + Quinte). Die App berechnet automatisch während des Stimmens die bei jedem Instrument unterschiedlichen Oberton-Strukturen „Inharmonizität“, so dass die Stimmung immer passt. Wir setzen Only Pure im täglichen Einsatz für unseren Konzertflügelverleih ein mit Nutzung u. a. durch Top-Künstler wie Lang Lang u. v. m. Die aktuelle App-Version ist nochmal Anwender-freundlicher optimiert worden. Sehr zu empfehlen!

### 1/5 — Fails to Deliver Real Value

*2025-12-16*

Tunic only: pure piano tuner offers little real value, and almost any competing option would be a better choice.

**Developer response:** Thank you for taking the time to leave feedback.

OnlyPure is a tuning tool developed for professional piano technicians, dealing with inharmonicity and the definition of "pitch" in a non-standard way — aspects that are not addressed by most general-purpose tuning apps.

We understand that different tools suit different workflows and expectations. If you would like to share specific points that did not meet your needs, we are always open to constructive feedback via our support channel.

### 4/5 — Accuracy.

*2024-08-22*

This is definitely a good app. But the reason why I gave it a four star rating is that it’s not properly calibrated to a 440. When I checked it with my other Tuning app and checked it with my Tuning for it showed that it was about, a few cycles off. I have to pull it up to A440 one to get a 440. if the developer can calibrate it to where it’s supposed to be I would give it a five star rating. As far as accuracy and tuning the piano itself it is great. Tune spin it pianos very well. Just make this one correction and it would indeed be great.

**Developer response:** Thanks for your feedback.

The calibration not being exactly 440Hz at A4 is a feature - please refer to our App's description for details. 

Nevertheless, we figure that some users wish to have a possibility to calibrate to exactly 440Hz. We will soon publish an update that allows for manual calibration.

### 5/5 — Tunic Only:Pure

*2023-04-11*

The best piano tuner app I have tried. As an amateur, I am surprised they advertise it as only for the professional. It even allows for unison tuning non-aurally, as aural tuning can be a challenge without training. Overall, very easy to use.

## Frequently asked questions about OnlyPure Piano Tuner

### What is the Stopper temperament in OnlyPure Piano Tuner?

The Stopper temperament is a unique tuning system optimized by OnlyPure Piano Tuner, based on pure duodecimes (octave + fifth) rather than traditional fifth-based temperaments. This method is valued for its clarity, stability, and musical transparency, and has been used by professionals for over 30 years.

### Can OnlyPure Piano Tuner be used for free?

Yes, a Free Demo Version is available. It allows you to test the tuning engine with full measurement accuracy within one central octave (C4–C5) and experience the manual tuning workflow. However, it is intended for evaluation purposes only and not for complete piano tunings.

### What are the differences between the Basic and Premium versions of OnlyPure Piano Tuner?

The Basic Version, a one-time purchase, offers the full keyboard range and manual note switching. The Premium Version, a subscription, includes the full keyboard range, automatic and chromatic note switching, additional temperaments, and calibration for concert pitch.

### How does OnlyPure Piano Tuner handle string inharmonicity?

OnlyPure Piano Tuner automatically compensates for string inharmonicity, stiffness, and damping. It uses a harmonic equivalent pitch to account for the effect of inharmonicity on piano tones, ensuring consistent tonal relationships and optimal compatibility with harmonic instruments.

### What devices is OnlyPure Piano Tuner compatible with?

OnlyPure Piano Tuner is available for iPhone and iPad devices. It is designed for professional use in concert halls, studios, and other professional environments.

### How often is OnlyPure Piano Tuner updated?

The latest version of OnlyPure Piano Tuner is 2.0, which was last updated on March 13, 2026. This indicates a commitment to ongoing development and improvements for the application.

### What is the pricing for OnlyPure Piano Tuner subscriptions?

OnlyPure Piano Tuner offers several subscription plans. The 'only:pure Basic' plan is $3.99/month or $44.99/year, both with a 14-day free trial. The 'OnlyPure Premium' plan is $7.99/month or $69.99/year, also with a 14-day free trial.

### Does OnlyPure Piano Tuner have ads?

No, OnlyPure Piano Tuner does not contain advertisements. The application is designed for professional use and focuses on providing a seamless and uninterrupted tuning experience.

## Version history (last 5 releases)

### 3.0.1 — 2026-08-23

New in version 3.0.1

Increased contrast for bright surroundings: Settings → Interface → Increased contrast. Needle, scale, icons and menu texts are then drawn more strongly.

### 3.0 — 2026-08-18

Überarbeitete Oberfläche mit Benutzerhandbuch: aktualisierte Menüführung, ruhigere Farben und angepasste Größen auf dem iPad. Unter „Informationen & Support“ finden Sie ein ausführliches Handbuch zu allen Funktionen mit praktischen Tipps und Hinweisen.

Instrumentenkatalog: Speichern Sie die Instrumente Ihrer Kunden mit Kammerton, Stimmung und weiteren Daten. Der Katalog lässt sich effizient sortieren und durchsuchen.

Stimmungskatalog: gleichstufige, historische und beliebig viele eigene Stimmungen.

Datensicherung: Sichern Sie Kataloge und Einstellungen automatisch in Ihr iCloud Drive oder von Hand als Datei.

Multi-Mikrofon-Analyse für stabilere Messwerte.

Dynamischer Messbereich: Bei stark verstimmten Instrumenten erweitert sich der Messbereich von ±50 auf bis zu ±200 Cent.

Monats- und Jahresabo beginnen jetzt mit einem kostenlosen Probemonat. Jederzeit im App Store kündbar; danach steht Ihnen weiterhin die kostenlose Demo zur Verfügung

### 2.1.1 — 2026-07-23

2.1.1:
- Bugfixes for restoring previous customer purchases.

### 2.1 — 2026-04-23

New in Version 2.1:

- Stabilized automatic note detection

- Notes can now be changed by swiping: swipe right = +1 semitone, swipe left = -1 semitone, swipe up = +1 octave, swipe down = -1 octave — available in all note recognition modes

- New display smoothing modes: strong, light, none, and adaptive. Tap the smoothing icon to cycle through modes. The new adaptive mode automatically adjusts smoothing based on cent deviation — stable near the target pitch, responsive further away. The smoothed range is adjustable via a slider (double-tap the smoothing icon)

### 2.0.1 — 2026-04-05

In Version 2.0.1 wurde ein Problem mit dem manuellen Kalibrierungsfaktor behoben (es fehlte eine Nachkommastelle). Weiterhin haben wir die Nutzerhinweise zur manuellen Kalibrierung überarbeitet.

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## More apps by Patrick Sebastian Stopper

- [TUNIC Unisono](https://appshunter.io/ios/app/tunic-unisono/id6443529669)
- [TUNIC Guitar Tuner](https://appshunter.io/ios/app/tunic-guitar-tuner/id6443751695)

All apps by Patrick Sebastian Stopper: https://appshunter.io/developer/1635946380

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-08-24.*