Verify an NMEA GGA checksum
Check whether the hexadecimal XOR checksum after the asterisk matches a synthetic GGA fix sentence.
Open exampleNMEA checksum calculator
Calculate and verify the XOR checksum for NMEA-0183 sentences and generate a standard sentence.
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The result will appear here as structured cards.
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Short, high-intent examples that are easy to open, share, and understand for search engines and AI systems.
Calculate a GPGLL sentence checksum
Enter only the NMEA body and generate a standard $...*XX sentence for checksum-range debugging.
Open exampleFAQ
These notes help users understand the results and help search engines and AI systems understand the tool.
What does NMEA checksum calculator do?
It helps you inspect or process this value and get a readable result quickly.
Is my input saved?
Local tools run in the browser when possible. Server-side checks only use the input needed to complete the lookup.
How do I verify an NMEA sentence checksum?
XOR every character between `$` and `*`, convert the result to two uppercase hexadecimal digits, then compare it with the value after the asterisk.
Why does an NMEA checksum fail after copying?
The usual causes are wrong copy range, missing fields, extra spaces, line breaks, stale checksum text, or mixing body-only and full-sentence input.
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