Frequently Asked Questions
Everything you need to know about authenticating your precious metal coins with Pingcoin.
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, comparing your coin's resonance frequencies against verified reference values.
How accurate is Pingcoin?
Most counterfeits use the wrong metal or dimensions, which shifts a coin's ring, and that is what Pingcoin detects. The app 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). We haven't yet published measured detection rates, so we recommend using the ping test alongside other verification methods like weight, dimensions, and visual inspection for valuable coins.
How much does Pingcoin cost?
Pingcoin offers platform-specific free allowances and paid plans: iPhone includes 15 free tests/month with $34.99/year, $89.99 lifetime, $3.99 24-hour pass, and $4.99 pack-of-25 options; Android includes 10 free tests/month with $28.99/year and $4.99 day pass options. Prices are US USD; local store listings are authoritative.
Does Pingcoin work on gold and silver bars?
No, Pingcoin is optimized for coins only. Bars have different acoustic properties due to their shape and may not provide reliable results. For bars, consider other verification methods like weight, dimensions, or professional assay services.
What coins does Pingcoin support?
Pingcoin supports 64 coin types including 39 silver coins (American Silver Eagle, Canadian Maple Leaf, Austrian Philharmonic, British Britannia, Chinese Panda, and more) and 25 gold coins (American Gold Eagle, Krugerrand, Canadian Maple Leaf, Austrian Philharmonic, and more). We're continuously adding new coins.
Does Pingcoin require internet?
No. Once installed, Pingcoin works completely offline. All coin reference data is stored locally on your device. Audio is analyzed on your phone and never leaves it; see the privacy policy for the test results the app sends.
What if my authentic coin shows a warning?
Coins have natural variation from manufacturing, wear, and handling. A warning means frequencies are outside the expected range—it doesn't confirm a fake. Test again somewhere quiet, holding the coin lightly at its center, tap its edge in a few places, and check its weight and dimensions. Don't clean a coin to test it: cleaning can damage its value. Some coin types also have overlapping frequency ranges. Join our community for support if you need help.
Can sophisticated counterfeiters beat this test?
Theoretically, a counterfeiter who uses the exact correct precious metal with exact correct dimensions would pass. Such a coin contains the real gold or silver, so the counterfeiter only gains the premium over metal value. The ping test catches fakes made of cheaper substitute materials; it can't tell an unofficial strike in the right metal from a mint coin. See our page on what the ping test can miss.
How does the acoustic analysis work?
When you tap a coin, it vibrates at specific frequencies determined by its material properties (density, elasticity) and geometry (diameter, thickness). Pingcoin captures this acoustic signature using your device's microphone and performs a Fast Fourier Transform (FFT) to identify the dominant frequencies. These are compared against known reference values for authentic coins.
What devices are supported?
Pingcoin is available for iPhone on the App Store and for Android devices running Android 5.0 (Lollipop) or higher.
Does my phone need a good microphone?
Most modern smartphones have sufficient microphone quality for accurate testing. The app analyzes frequency ratios rather than absolute values, making it robust to microphone differences.
Can I test coins in plastic holders or capsules?
For best results, test coins outside of holders. Plastic capsules dampen the ring and may affect accuracy. If you must test in a holder, understand that results may be less reliable.
Is Pingcoin better than a Sigma Metalytics verifier?
They serve different needs. Sigma Metalytics ($1,500+) uses electromagnetic analysis and can test through packaging—ideal for dealers. Pingcoin uses acoustic analysis with platform-specific App Store and Google Play pricing and is perfect for individual collectors and investors who need an affordable, portable solution. For most personal use cases, Pingcoin provides excellent verification at a fraction of the cost.
How do I get help or report issues?
You can email [email protected], report bugs on our GitHub repository, or join our Discord community for real-time help. We also have comprehensive documentation at pingcoin.com/docs.
Ready to verify your coins?
Join the collectors who have downloaded Pingcoin over 50,000 times for their precious metal authentication.
Still have questions? Contact support or check out our documentation.