GuitarTuner.io is a free browser tuner for acoustic guitar, electric guitar, and bass. It uses a microphone to detect pitch in real time and indicate whether a note is sharp, flat, or in tune; audio processing takes place in the browser. The site lists 69 free tuners across standard, drop, open, modal, bass, ukulele, mandolin, banjo, and extended-range tunings. Users can create custom tunings with any number of strings and notes. The tuner is a Progressive Web App that can be installed from a browser, and it works offline once installed and cached. A modern browser and microphone are required; listed supported devices include iPhone, Android, Windows, Mac, and Chromebook. The site also offers an interactive chord library with diagrams and audio playback, plus a metronome with adjustable tempo, time signatures, and visual feedback. The browser tuner requires no account, paid upgrade, or app download. A proposed native iPhone and Android Pro app, listed at 4.99 USD per once, is only a demand test and is not available to buy.
Who it is for
It suits players who want a browser-based tuner with alternate and custom tunings, plus basic practice tools. It also suits people who want offline use after installing and caching the web app.
What is good
- Lists 69 free tuners across several instrument types
- Custom tunings allow any number of strings and notes
- Works offline after installation and caching
- Includes chord diagrams, audio playback, and a metronome
What to know first
- Requires a modern browser and microphone
- Pro native app is not yet available to buy
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GuitarTuner.io: the full review
GuitarTuner.io offers tuning in the browser, with offline use after installation and caching. The proposed native Pro app is not available to buy; the browser tuner is free without an account or upgrade.
GuitarTuner.io is a browser-based tuner for guitar, bass and other stringed instruments. It suits players who want alternate or custom tunings alongside simple practice tools. Its broad free tuner selection is a strong draw, though offline use depends on installing and caching the web app first.
Overview
The tuner listens through a device microphone and processes audio in the browser, giving real-time feedback on whether a note is sharp, flat or in tune. It works without an account, paid upgrade or app download, making it a straightforward choice for occasional tuning as well as regular practice.
Beyond tuning, the site has a chord library with interactive diagrams and audio playback, plus a metronome with adjustable tempo, time signatures and visual feedback. These additions make it more useful during practice than a tuner alone, but they do not replace a dedicated lesson or recording tool.
Key features
Many tunings, including custom setups
GuitarTuner.io offers 69 free tuners across standard, drop, open, modal, bass, ukulele, mandolin, banjo and extended-range tunings. Players who switch tunings or instruments can find a suitable option without paying; custom tunings with any number of strings and notes add flexibility for less common setups.
Browser-based pitch feedback
Real-time pitch detection marks notes as sharp, flat or in tune. Because audio is processed in the browser, the core experience depends on a microphone-equipped device and a modern browser rather than a native app.
Installable, with a setup requirement for offline use
The Progressive Web App can be installed directly from a browser, without an app store download. Once installed and cached, it works offline. That is useful for practice without a connection, but it is not an offline-first option: installation and caching must happen beforehand.
Pricing
The Free web tuner is free forever. It includes the browser tuner and requires neither an account nor a paid upgrade. Since the core tuner is already free, it is a good fit for players who want to avoid subscriptions or one-time charges.
GuitarTuner Pro (proposed) is priced at 4.99 USD per once, billed Lifetime, for a proposed native iPhone and Android app. It is only a demand test and is not yet available to buy, so it is not a current upgrade option.
Platforms
The browser tuner is listed for Android, iOS, macOS and Windows. The install page also names Chromebook devices, provided they have a modern browser and microphone. The web app can be installed without an app store download, while the proposed native iPhone and Android Pro app is not yet for sale.
Who it's for
GuitarTuner.io is best for guitar and bass players who want a free browser tuner, especially those who use alternate or custom tunings. Its additional ukulele, mandolin and banjo tuners broaden its appeal to other string players. The chord diagrams, playback and adjustable metronome are useful practice companions, while offline access suits users willing to install and cache the app in advance.
It is less suitable for someone who specifically wants a native phone app today or needs offline tuning without prior setup. A working microphone and modern browser are essential.
Pros and cons
- Pro: 69 free tuner options and custom tunings cover a wide range of instruments and setups without an account or upgrade.
- Pro: Chord diagrams with audio and a configurable metronome add practical tools for practice.
- Pro: Browser installation enables offline use after the app has been cached.
- Con: Offline access requires installation and caching first, so it is not ready offline out of the box.
- Con: The proposed native Pro app cannot currently be purchased; users must use the browser version.
Alternatives
Centerline is worth considering for iPhone, Android or Mac users who want chromatic tuning with four display views and a guitar mode; its free Chromatic plan is limited to that core feature set, while Centerline Complete costs 3.99 USD per once.
ChromTuner suits users seeking a free chromatic browser tuner with an LED meter and microphone input, or a free iPhone app. Fender Tune is another free option for Android and iOS; Tune Plus requires a Fender account.
JustATuner is an alternative for Linux, Mac or Windows users. n-Track Tuner offers Android and iOS apps, with a free version and a Pro version for 2.99 USD per once. DaTuner is an Android option with a free ad-supported tier and a Premium tier that removes ads and adds features. Cifra Club Tuner is another free-plan choice for web, iOS and Android.
Browse more options in Musical Tuner Apps.
Verdict
Choose GuitarTuner.io if you want a free, account-free browser tuner with unusually broad tuning coverage and useful practice tools. Its main advantage is getting that range at no cost; look elsewhere if you need a native mobile app now or offline operation without prior installation and caching.
Get started with GuitarTuner.io
- Open GuitarTuner.io in a modern browser on a device with a microphone.
- Allow microphone access to use real-time pitch detection.
- Select one of the listed tunings or create a custom tuning.
- Install the Progressive Web App from the browser if you want offline use after it is cached.
- Use the chord library or metronome for additional practice tools.
Questions about GuitarTuner.io
Is GuitarTuner.io free?
Yes. The browser tuner is free forever at no cost, with no account or paid upgrade required.
Which instruments can it tune?
The stated purpose covers acoustic guitar, electric guitar and bass. Its 69 listed tuners also include options for ukulele, mandolin, banjo and extended-range tunings.
Can it work offline?
Yes. It works offline after it has been installed as a Progressive Web App and cached.
Which devices are supported?
The install page lists iPhone, Android, Windows, Mac and Chromebook devices with a modern browser and microphone.
Is there a native Pro app?
A proposed native iPhone and Android Pro app is listed as a 4.99 USD lifetime offer, but it is only a demand test and is not available to buy.
Who created GuitarTuner.io?
The site identifies John Sorrentino as its creator.
GuitarTuner.io plans and pricing
All plansCompared on musical tuner apps
- Free plan
- Yes
- Alternate tunings
- Yes
- Offline mode
- Yes
- Available platforms
- both



