From spreadsheet coordinates to usable GeoJSON

Use a single header row and separate columns for latitude, longitude, and attributes such as site_id or name. Export the sheet as UTF-8 CSV, or paste a tab-separated table with its headers. Keep IDs such as 0012 as text in the spreadsheet so leading zeros survive before they reach the tool.

Both CSV tools accept up to 5,000 data rows and 2 MB. Split larger files first. Quoted fields can contain separators, but every record must match the header structure. Use unique, nonblank headers and remove notes or totals that are not location records.

site_id,name,latitude,longitude
0012,Taipei,25.033,121.5654
0013,Kaohsiung,22.6273,120.3014

Select latitude and longitude columns explicitly. Latitude must be between −90 and 90, and longitude between −180 and 180. Those checks catch some mistakes but cannot prove that columns are correctly assigned. If both values fit both ranges, swapping them may still pass validation; compare a known location with the source documentation.

Confirm that the source is WGS84 longitude/latitude before making GeoJSON. A column named X is not proof of longitude. Taiwan TWD97 / TM2 easting and northing are projected coordinates in metres, not WGS84 decimal-degree input. These tools do not infer a CRS or transform projections. Perform the documented CRS transformation in GIS software first. An address also needs a separate geocoding step.

Decimal degrees (DD) express a position as 25.033 and 121.5654. Degrees, minutes, seconds (DMS) express the same position as 25°01′58.8″N and 121°33′55.44″E. Changing notation does not change the reference system or improve the original measurement accuracy.

Use the latitude/longitude converter for plain coordinate pairs, including multiple lines of DD or DMS. Choose the CSV coordinate converter when each position belongs to a record whose other columns must stay attached. GeoJSON coordinates must be decimal degrees, so convert a DMS table to DD before the GeoJSON step.

Load the header-based CSV or TSV, select the latitude and longitude fields, and choose DD → DMS or DMS → DD to match the source. Review the converted coordinate columns alongside the untouched attributes. A store code, comment, or category should remain a string associated with its original row.

When an error is reported, use the row and column information to correct the source. Blank coordinates, nonnumeric DD, an invalid DMS direction or minute/second value, and values outside the allowed range need attention. Export remains disabled until all errors are fixed; a partial download could silently omit the very sites you need.

Load the verified WGS84 decimal-degree table into CSV to GeoJSON and map the two coordinate columns. Each row becomes a Point feature. GeoJSON stores its coordinate array in [longitude, latitude] order, even if your spreadsheet lists latitude first. The two sample rows therefore begin [121.5654, 25.033] and [120.3014, 22.6273].

The remaining columns become string properties on the corresponding feature, preserving labels and IDs without guessing number or date types. The output is a FeatureCollection containing multiple Point features. For one manually entered location, use the separate GeoJSON Point Generator instead.

Use the local longitude/latitude scatter preview to spot outliers and unexpected clusters. Compare axis order, source CRS and sample positions with your source data.

Resolve every reported row error, export, and compare the feature count with the number of intended input records. Inspect a known feature’s coordinates and string properties in the downloaded JSON. Import it into your target GIS with a reference map for a final location check. Recheck precision and any changes made by the receiving application.

The distance calculator estimates great-circle distance between two positions. It is useful for an approximate geographic separation, not for driving distance, travel time, a walking route, or elevation-aware surveying. Two nearby coordinates can still require a long road journey.

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