GC Code ↔ GC ID Converter

Geocaching utilities · Code conversion

Convert a geocache's public GC code (such as GC16XYD) to its numeric database ID, or convert the ID back to the GC code. Works with both older hexadecimal GC codes and newer base-31 codes.

GC code or numeric IDYou can also paste a Geocaching.com or coord.info cache URL.

Conversion directionWhen auto-detecting, a value made only of digits is treated as a numeric ID.

Try:

Numeric GC ID

718967

Open cache listing ↗

GC codeGC16XYD

Numeric GC ID718967

Number systemBase 31

Conversion noteBase-31 value minus 411120

Batch converter

Convert multiple GC codes or numeric IDs in one step. Enter one per line, or separate items with commas, semicolons, or spaces. Each valid result can be copied individually or exported as CSV.

Codes / IDs

Batch conversion direction

In auto mode, prefix hexadecimal-only GC codes with GC to distinguish them from numeric IDs.

No batch results yet.

How the conversion works

Older GC codes: Up through GCFFFF, the characters after GC are a hexadecimal (base-16) representation of the numeric ID. For example, GC28 corresponds to ID 40.

Newer GC codes: Starting at GCG000, geocaching uses a custom base-31 alphabet: 0123456789ABCDEFGHJKMNPQRTVWXYZ (omitting I, L, O, S, U). Subtract 411120 from the base-31 value to get the numeric ID; add it when converting back.

Note: The converter performs the code-to-number calculation only. It does not query Geocaching.com or verify whether a cache actually exists. In GC-code inputs, O and S are accepted as common substitutions for 0 and 5.