Precious Coin Tester

How to tell if a gold coin is real?
How to test silver coins to avoid buying fakes?

Precious coin tester is here to help you!

What is it?

Precious coin tester is an application which helps to detect fake gold/silver coins. A user knocks the coin with another hard object (another coin, a key, etc.), and the app provides you the result. The limitations of the app are as follows:

  • It can be only used to test round gold/silver coins without hole.
  • It can only test the content of precious metal in the coin. The app cannot distinguish a fake coin of similar or the same percentage of precious metal from the real, original one.
  • Minimum fineness requirement: gold 7%, silver 20%; result might be inaccurate if gold <20% or silver <50%.

How to use?

Run a test

  1. Open the app, select a coin from the catalog, or enter parameters for user-defined coins.
  2. Click on Check to start the analysis.
  3. While the progress bar is growing, hold the coin on the tip of one finger, and knock the coin briefly with another hard object near the mic of your phone/tablet.
  4. The coin generates its own sound after the knock. Hold still the coin while it rings.
  5. When the sound of the coin has diminished, knock it again. (Leave at least 1 second between to knocks)
  6. Repeat Step 5 until the progress bar finishes.

Please watch demonstration or check Common mistakes & Best practices.
Detailed documentation is available here

Read the result

Three stars are used to show the quality of your coin:

  • ⭐⭐⭐ 3/3: The coin passes the test: the precious metal content is almost the same(1) as its nominal value (only reserved for coins selected from catalog).
  • ⭐⭐ 2/3: The coin passes the test: the precious metal content is close to its nominal value.
  • ⭐ 1/3: The coin probably fail the test: the precious metal content is probably different from its nominal value, or the actual diameter and weight may be different from the nominal values.
  • 0/3: The coin fails the test.

Unstable result: Please test again as the sound quality is poor. We are not sure about the result.

(1) For app versions equal to or greater than 1.4.0, 3-star results (⭐⭐⭐ 3/3) indicate the following criteria:

  • The anticipated silver content should not fall below the nominal value by more than 10% for silver coins.
  • The anticipated gold content should not fall below the nominal value by more than 5% for gold coins.

Results rated with 2 to 3 stars are considered satisfactory, indicating that the coin has passed the test successfully. On the other hand, results rated with 0 to 1 stars are deemed unsatisfactory, suggesting that the coin has failed or is likely to fail the test. All results provided are based on our best knowledge regarding those coins. It is important to note that they are for informational purposes only and do not come with any warranty or guarantee.

Sources of bad result?

Got a bad result? Let’s find out why.

Maybe it is a false negative. There are 3 major reasons for this:

  1. Inaccurate parameters: this often happens with user-defined coins, or catalog coins without Verified mark (✔️). Please remeasure the coin, or double check the input parameters.
  2. Ping too frequently: pinging the coin too fast makes the app treat ping as background noise.
  3. Noisy environment: the app may wrongly treat environment noise as coin ping, although this rarely happens with our robust algorithm.
  • Another major reason is that the coin has a wrong purity, meaning that the coin is not a genuine one.

More recommendations can be found here.

Replay the last test

You can reply the last test by clicking on the Replay button on the interface. The app will play you back the sound registered during the last test.

Want a try without any silver/gold coin?

Youtubers can help!
For example, in this video
[1:47] Real silver eagle: got 3 stars from app
[1:59] Fake silver eagle: got 0 star unstable result from app
[6:52] 50 doller gold eagle (by guessing from image): got 2 stars from app
Since the quality of sound in videos is not as good as real tests, you may have frequently “unstable result”.
More examples.

How does it work?

Each object has its own proper sound. This sound depends on various characteristics of the object.
Coins have their special sound as well. The app collects the sound generated by the coin under test, and analyse the coherence between this sound and the information provided by the user. The level of the coherence is returned as result.

More explanation in this video
Some known failure cases can also be helpful to evaluate the application.


Plan Free Basic
Service - access more than 100 catalog coins - access all catalog coins (more than 30k)
- can define own coin parameters
Price (Excl. Tax) $0 / month $3.00 / month

More on free coin list and subscription management.


Is it secure to use the application?

Yes. The application neither askes for your personal data nor uses GPS information. It needs only microphone and writing to storage permissions. As protocol, IP address is publicly available to the whole internet. If you feel uncomfortable with it, a VPN can be used to mask your true IP address.

Why it does not work on my device?

There are different configurations on some devices and the application may not cover all of them. Please don’t hesitate to contact us, we try to fix the problem as soon as possible.

How to prevent from dropping coins?

The Pocket Pinger can help out. Please check more information.


By downloading, accessing or using Precious coin tester app or any page of this app, you signify your assent to this disclaimer. The contents of this app, including without limitation, all data, information, text, graphics, and other materials are provided as a convenience to our app users and are meant to be used for informational purposes only. We do not take responsiblity for decisions taken by the user based on the information provied in this app.

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