Coordinate CSV checker & GeoJSON export
Check WGS84 point coordinates by original CSV line, review errors and warnings, and export GeoJSON locally in your browser.
For WGS84 decimal-degree points only. No CRS detection, reprojection, or automatic longitude/latitude swapping. Confirm your source CRS before continuing.
1. Read a CSV
Pasted text and local files are processed in this tab: no upload, map requests, or input written to browser storage. Use Clear data to remove the current working data.
Up to 2 MB (2,000,000 bytes), 10,000 data records, and 100 columns. Supports quoted cells, doubled quotes, multiline cells, CR/LF/CRLF and a UTF-8 BOM. Blank data records are checked, not skipped. A final line ending does not add a record. File imports preserve cell line endings until you edit the text; pasting or editing may normalize them to LF.
Try an original sample
Three valid points
Comma; map longitude and latitude. 3 valid records.
name,longitude,latitude
Demo West,-73.9857,40.7484
Demo East,139.7671,35.6812
Demo South,151.2093,-33.8688Errors, duplicates & (0,0)
Comma; 6 records: 3 valid, 3 errors, 3 warning records. Duplicates and (0,0) stay in the export.
name,longitude,latitude
Good,-73.9857,40.7484
Missing,,35
Not numeric,null,20
Out of range,181,25
Duplicate,-73.9857,40.7484
Check origin,0,0Quoted multiline cells
Semicolon; 2 valid records. Includes a UTF-8 BOM, CRLF, embedded quotes and multilingual text.
name;longitude;latitude;note
"Demo, quoted";-0.1276;51.5072;"First line
Second line with ""quotes"""
中文・日本語;120.5;30.5;Unicode example2. Map and check
Use plain decimals with a dot: longitude −180…180, latitude −90…90, inclusive. Signs and surrounding whitespace are accepted; scientific notation, decimal commas, DMS, null, NaN and Infinity are rejected. Range checks cannot identify a wrong CRS or swapped axes when both values are in range.
Choose a sample, paste text or select a file.
3. Review and export
- Data records
- 0
- Valid records
- 0
- Error records
- 0
- Warning records
- 0
- Need review
- 0
Warning records are valid and included. Duplicates use parsed numeric coordinates; no points are merged. (0,0) may be real—verify your source.
Original physical line numbers include the header and multiline cells. Long values are shortened on screen; exports contain complete values.
| Source line(s) | Longitude column (X) | Latitude column (Y) | Result |
|---|
Open in QGIS
- Add the exported GeoJSON as a vector layer, or drag it into QGIS.
- For the original CSV, use Delimited Text: choose its delimiter, X = longitude, Y = latitude, and WGS 84 (EPSG:4326) only if confirmed.
QGIS: delimited text and vector data
GeoJSON uses [longitude, latitude] in WGS84. Original cells remain strings in properties; geometry uses JavaScript numbers, so very long decimals can round. Feature IDs are source start lines. The error CSV contains only rejected records, reasons and source text; it is a diagnostic report, not a corrected coordinate file. Formula-like text gets an apostrophe prefix for spreadsheet safety; plain negative numbers are unchanged. Do not remove the protective prefix from untrusted text.
GeoJSON coordinate specification