NMEA sentence parser
Decode NMEA 0183 GPS sentences into readable, named fields.
NMEA sentence parser
Paste raw NMEA 0183 sentences from a GPS receiver, chartplotter or GNSS logger and this tool decodes each line into named fields you can actually read — latitude and longitude instead of a ddmm.mmmm string, "GPS fix" instead of a bare status code, a proper timestamp instead of two separate time and date tokens. It understands the six most common sentence types: GGA (fix data), RMC (recommended minimum), GLL (position), GSA (DOP and active satellites), GSV (satellites in view) and VTG (course and speed).
Use Sentence type to isolate one message kind from a mixed log, or leave it on All types. Verify checksum recomputes the XOR checksum after the asterisk on every line and flags any mismatch, so a corrupted capture doesn't quietly look valid. Coordinate format switches between decimal degrees and degrees-minutes-seconds, and Describe fix quality and satellites turns numeric codes into plain words. Combine date and time into ISO 8601 carries the date from the most recent RMC sentence forward onto any GGA or GLL sentence that follows it, so a stream with only one date sentence still gets full timestamps throughout. Speed unit converts between knots and km/h, and Output format switches between a full field table, a compact one-line-per-sentence summary, and a bare list of latitude/longitude pairs for plotting a track.
A sentence with no checksum at all is parsed but not flagged — only a checksum that is present and wrong counts as bad. Two-digit NMEA years are read as 20xx, since the format itself carries no century and every receiver still in service is well past 2000. Windows and Unix line endings are both accepted, and the tally under the output reports how many lines were recognized sentences, how many had a bad checksum, and the output size.
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