Convert Leica GSI (GSI-8 / GSI-16) to CSV
Leica instruments and data collectors store measurements and coordinates in the GSI format — a fixed-width, word-based layout that is almost impossible to read in a spreadsheet. Each block (one line) is a run of words; each word is a 2-digit word index (WI), four characters of information, a sign, and a data field. GSI-8 packs the data into 8 characters; GSI-16 uses 16 and prefixes each block with an asterisk. The word index tells you what the value is: 11 is the point number, 71 a code, 81/82/83 the target easting, northing and elevation, and 84/85/86 the station coordinates.
The catch that trips up generic converters is the implied decimal. A coordinate word does not store 1024.770; it stores the integer 1024770 with a units flag that says where the decimal goes. Open the file in Excel and you get seven-digit integers, not metres. This tool reads the units flag on each word and scales the value back, so 81..10+0000000001024770 becomes an easting of 1024.770.
The result is a clean point file: point number, code, northing, easting and elevation, in PNEZD or PXYZD column order. Nothing is uploaded — the GSI is parsed in your browser — and you can add a points DXF in the same export.
Open the converter — free, no upload
How to convert a Leica GSI file to CSV
- Download the job off the Leica instrument or controller as a .gsi file.
- Drop it on the tool. The format (GSI-8 or GSI-16) is detected automatically; you can also force it from the dropdown.
- Check the point count in the summary, then pick PNEZD or PXYZD column order.
- Click Export to download the CSV (and tick the DXF box for a points drawing).
Questions
What's the difference between GSI-8 and GSI-16?
The size of the data field in each word: 8 characters in GSI-8, 16 in GSI-16. GSI-16 blocks also start with an asterisk and allow longer, alphanumeric point numbers and codes. The tool detects which one a file uses and parses accordingly.
Does it handle the implied decimal correctly?
Yes. GSI coordinate words store an integer plus a units flag. The tool reads that flag — millimetre resolution divides by 1,000, tenth-of-a-millimetre by 10,000 — so coordinates come out in real units, not as raw integers.
Which word indices are read?
Point number (11), code (71), target coordinates easting/northing/elevation (81/82/83) and station coordinates (84/85/86). Angle and distance observation words are ignored, since this tool exports reduced coordinates.