Why this tool is useful
Use packed BCD conversion for payment, telemetry and legacy hardware fields where each nibble must remain a decimal digit and leading digit sequences must not pass through floating-point arithmetic.
Developer & Data · runs locally
Packed BCD Converter
Encode decimal digit strings as packed binary-coded decimal bytes or validate and decode packed BCD hexadecimal without numeric rounding.
Ready. Your working data stays in this browser.
How it works
Encoding pairs decimal digits into high and low nibbles with a leading zero pad for odd lengths; decoding rejects any nibble A through F and removes only the documented odd-length pad.
Practical example
Decimal digits 12345 are padded and packed as bytes 01 23 45; decoding those bytes returns the original five-digit sequence.
Validation
The calculation is deterministic and explains validation errors instead of silently changing invalid input.
Privacy boundary
Input and output remain in this tab. Copy and download happen through browser APIs without a server upload.
Result passport
Every run reports its tool mode, timestamp and input/output size so transformed data can be audited.