Documentation
FAQ

Frequently Asked Questions

General Questions

What is the ping test?

The ping test is a time-honored method where you tap a coin and listen to its ring. Genuine precious metals produce a distinctive, sustained tone, while counterfeits sound dull. Pingcoin digitizes this test with precision audio analysis.

How accurate is Pingcoin?

Pingcoin compares your coin's resonance frequencies against reference values recorded from genuine coins (for some coins, values predicted by our resonance model, marked as such in the tester). It catches fakes made of the wrong metal or with the wrong dimensions; we haven't yet published measured detection rates. Some coins with similar composition may have overlapping frequencies. We recommend using the ping test alongside other verification methods (weight, dimensions, visual inspection).

Can I rely solely on this test?

The ping test is a powerful screening tool, but we recommend using multiple verification methods for valuable coins. Check weight, dimensions, and visual details as well.

Technical Questions

Does it work on bars?

The app is optimized for coins. Bars have different acoustic properties and may not provide reliable results.

What if my authentic coin isn't recognized?

Coins can have natural variation due to wear and minting differences. A "Not Recognized" result means the frequencies don't match our database—it doesn't necessarily mean the coin is fake. Join our Discord community for support.

How does the acoustic analysis work?

When you tap a coin, it vibrates at specific frequencies determined by its material properties, weight, and dimensions. Pingcoin captures this acoustic signature using your device's microphone and performs a Fast Fourier Transform (FFT) to identify the dominant frequencies. These are then compared against known reference values for authentic coins.

Privacy & Security

Is my data private?

The app analyzes the sound on your phone, so no audio leaves your device. It sends us the result of each test (the coin, the verdict and the measured frequencies, as numbers) to improve accuracy, with nothing that identifies you. Submitting a coin we don't support yet is optional and sends the photos, recording and email address you enter. The free coin tester on this website sends a fifth of a second of sound after each strike to our server, which analyzes it and discards it. See our Privacy Policy for full details.

Does the app require internet?

No. Once installed, Pingcoin works completely offline. All coin reference data is stored locally on your device.

Compatibility

What devices are supported?

Does my phone need a good microphone?

Most modern smartphones have sufficient microphone quality for accurate testing. The app is designed to work with standard phone microphones.

Pricing & Plans

What's included in the free plan?

The free plan includes:

  • iPhone: 15 free tests per month
  • Android: 10 free tests per month
  • Access to every supported coin
  • Full offline functionality
  • Instant results

How does the premium plan work?

Paid plans are platform-specific. In the US, Android annual access is $28.99/year; iPhone annual access is $34.99/year, with $89.99 lifetime, $3.99 24-hour pass, and $4.99 pack-of-25 options. Local App Store and Google Play prices are authoritative. Paid plans provide:

  • Unlimited verdicts
  • Priority support

Can I upgrade or downgrade anytime?

Yes! You can upgrade to premium or cancel your subscription at any time through the App Store or Google Play Store.

Support & Community

How can I get help or provide feedback?

You can:

Where can I find more information?

Visit our GitHub repository (opens in a new tab) for more technical information and to report issues.

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