Luhn checker
Validate Luhn-checked numbers (credit cards, IMEI, ID numbers) and propose the correct check digit.
Also known as: Luhn algorithm validator, Check digit calculator.
100% offline · macOS, Windows & Linux · free for personal use
// overview
What it does
Luhn checker is one of 55 tools in Hexkit, a desktop developer toolbox that runs entirely on your own machine. Validate Luhn-checked numbers (credit cards, IMEI, ID numbers) and propose the correct check digit.
Because Hexkit is a native app rather than a web page, anything you paste into the luhn checker stays local — there are no uploads, no accounts and no telemetry. You can decode tokens and inspect encoded data even with the network turned off, which makes it safe for tokens, keys and production data.
// steps
How to use Luhn checker
- 1
Open Hexkit and select "Luhn checker", or press the command-palette key and start typing its name.
- 2
Paste the text or token you want to encode or decode. Validate Luhn-checked numbers (credit cards, IMEI, ID numbers) and propose the correct check digit.
- 3
Read or copy the result. Everything is computed locally by Hexkit's Rust core, so nothing is ever uploaded.
Tip: the command palette opens any tool in one keystroke.
// faq
Frequently asked questions
- Is Luhn checker free?
- Yes. Luhn checker is part of Hexkit, which is free for personal and non-commercial use on macOS, Windows and Linux.
- Does Luhn checker work offline?
- Completely. Hexkit runs every tool locally with no network access, so Luhn checker works on a plane or an air-gapped machine.
- Is my data uploaded anywhere?
- No. Hexkit makes no network calls and has no telemetry — whatever you paste stays on your computer.
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Related tools
Use Luhn checker without sending your data anywhere.
Luhn checker ships inside Hexkit — a free, offline developer toolbox for macOS, Windows and Linux. No account, no uploads.