Luhn Checker
Validate credit card and ID numbers with the Luhn checksum and detect the possible card network.
Format/structure validation only — it proves the number is well-formed, NOT that it exists or has funds. Nothing is transmitted.
About Luhn Checker
Validate credit card and ID numbers with the Luhn checksum and detect the possible card network.
Luhn Checker does the security work in your browser using well-known algorithms, so sensitive input never has to be sent to a remote server.
How to Use Luhn Checker
- Enter the secret text, file or value you want to process.
- Choose the algorithm, key or options required.
- Run the operation — the output appears instantly and locally.
- Copy the result safely.
Key Features
- Encryption and hashing run locally — your secrets stay on your device.
- Uses established, well-documented algorithms and standards.
- No account, no key storage, no data retention.
Frequently Asked Questions
Is Luhn Checker safe to use with sensitive data?
Yes. Luhn Checker runs entirely inside your browser using in-page cryptography, so your inputs are never uploaded, logged or shared.
Is Luhn Checker free to use?
Yes. Luhn Checker is completely free with unlimited use — no account, download or payment required.
Is my data uploaded to a server?
No. Luhn Checker runs entirely in your browser. Your inputs are never sent to our servers or stored anywhere.
Does Luhn Checker work on mobile?
Yes. The interface is fully responsive and works in any modern browser on Android, iPhone, tablets and desktops.
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