Field guide
A practical guide to coordinate and map file exchange
Start with source documentation, then review each field, coordinate meaning and deliverable.
Turn a coordinate table into a clear map handoff
A CSV to KML converter helps when the recipient needs to view named locations or a route in a KML-compatible mapping application. It also helps in the opposite direction: a supplied map file may contain positions you need to review in a spreadsheet or another point-file workflow. This page keeps both directions together so you can inspect coordinates and exchange supported content without changing to a separate tool for each file extension.
Begin by choosing the direction. Table input accepts CSV, text or one explicitly selected Excel worksheet. Map input accepts KML or a KMZ archive containing exactly one KML document. Processing stays in your browser. The application does not load external map tiles, linked icons, remote models or network-linked documents. Keep the received file as your original record, especially when its styling or unsupported objects matter to the delivery.
Confirm WGS84 longitude and latitude before export
The first coordinate role is longitude and the second is latitude, both expressed in decimal degrees. A value such as 500000 from a projected grid is not a longitude. Range checks reject impossible angles, but they cannot discover a wrongly identified datum when the numbers still look plausible. Confirm the source reference from its documentation, not from the appearance of the preview.
If your table contains known WGS84 UTM coordinates, use the projection converter first and then continue here with the geographic result. CGCS2000 geographic coordinates are not automatically WGS84, and a local construction grid needs a documented relationship before it becomes map data. The WGS84 confirmation is deliberately separate from field mapping so a convenient column layout cannot substitute for a coordinate reference decision.
Preserve names while mapping table columns
Map name, longitude, latitude, optional height and optional description using one-based column numbers. Use zero for an absent optional field. The name can contain leading zeros, spaces or ordinary punctuation. XML-sensitive text is escaped during export, and descriptions remain plain text rather than executing embedded HTML. Extra source columns are retained in the complete JSON report, not silently represented as exported KML attributes.
For XLSX files, choose the correct worksheet before reviewing the fields. Stored numeric coordinate values are used instead of rounded display text. Explicit zero-padded integer formats are preserved for names, while formula, date and error cells require correction or conversion to verified plain values. Do not infer that the tool has recalculated an Excel formula: it has no spreadsheet calculation engine and intentionally refuses that ambiguity.
Choose separate points or one ordered line
Point output creates one Placemark per input record, using the mapped name and description. This is suitable for named features, inspection locations or a set of survey positions to be visually reviewed. Missing names stay empty; the tool does not invent field identifiers. Repeated names are preserved because a map can legitimately contain more than one feature with the same displayed label.
Line output creates one LineString using every row in its original order. At least two vertices are required. Review the ordering before export, since sorting by name or Easting could change the route substantially. KML line vertices do not receive the table's individual name and description fields in this implementation. Those values remain in the JSON source record, and the interface tells you about this omission before approval. Use point output when per-location labels are essential.
Make the height mode match the data
Height mode is a semantic choice. Clamp to ground tells the viewer to place geometry on its terrain, so a supplied height is not used as an absolute survey elevation. Relative to ground interprets a value as metres above the terrain at that position. Absolute interprets it as a height in metres above sea level according to the receiving KML application's convention. Choose a mode that matches the intended communication and the actual data meaning.
The tool does not convert ellipsoidal heights into elevations, calculate a geoid separation or certify a vertical datum. For absolute and relative output, every row must include a height; an empty cell is not silently replaced with zero. For clamped output, missing heights remain absent. If a GNSS file supplies ellipsoidal height, do not simply select absolute because the column is labelled elevation. Establish the required vertical conversion separately or choose an appropriate visual-only clamped delivery.
Understand the difference between KML and KMZ
KML is an XML document describing map features. KMZ is a ZIP archive that can package a KML document and related assets. The map geometry does not become more precise merely because it is compressed. This tool can export the generated document as KML or as a KMZ containing doc.kml, so the recipient can use whichever packaging their workflow expects.
On import, this version requires exactly one KML member. An archive containing several KML documents is rejected with a member list rather than guessing which one represents the intended delivery. Supporting asset names remain in the archive report, but linked images, sounds, textures and styles are not reproduced. File size, archive entry and expanded-size limits are checked before normal processing. These boundaries are intended to make failure clear rather than produce an unexplained partial map.
Extract point and line coordinates with context
KML to CSV and XLSX extraction supports Point and LineString geometry, including supported members within MultiGeometry. Each line vertex becomes a row with its feature number and vertex order. The output also retains the Placemark name, description, folder path, altitude mode, KML identifier and ExtendedData values represented as JSON text. A line therefore produces multiple rows; row count is not the same as feature count.
The point table is an extraction, not a lossless rewrite of the complete map document. Styles, icons, display settings and unimplemented geometry are not recreated. Polygon, model, overlay, track and network-link content is listed as unsupported. Review that list and explicitly approve the supported subset before export. Invalid coordinates in an otherwise supported feature block export, while the report retains the original document for investigation.
Use the preview as a coordinate check
The local preview plots longitude against latitude for up to one thousand vertices. It does not download a basemap and does not measure ground distances or prove line topology. A degree of longitude does not have a constant ground length across latitudes, and locations near the date line may appear far apart on this simple coordinate plot. Use the numeric table and an appropriate mapping application for the final geographic review.
The table is paginated, while exported files and the JSON report retain all supported vertices. Clicking a plotted location helps locate its table page. Review names, coordinate signs and height modes, and compare at least one independently known location before accepting a handoff. Any input edit removes the previous result and approval, so a download cannot silently reuse an outdated preview.
Export a usable spreadsheet and continue the workflow
CSV contains explicit columns for name, longitude, latitude, altitude, description, geometry, feature, vertex, folder, altitude mode, KML ID and attributes. XLSX provides the same values as text cells to preserve identifiers and decimal strings. If a spreadsheet formula needs numeric columns, convert those columns deliberately after confirming their interpretation. Formula-like names or descriptions remain text in XLSX rather than becoming executable formulas.
Imported coordinates can continue to projection conversion without another upload. Height is deliberately left unmapped during this handoff because clamped, relative and absolute KML values must not automatically become a common survey elevation field. The original altitude and mode columns remain in the transferred source for review. Choose the target projection and confirm its reference before continuing to planar point tools such as filtering or DXF export.
Keep the original and a complete conversion record
Save the original file, generated output and JSON report together. The report records the chosen geometry, mapped fields, reference note, errors and stated omissions. On import it retains the original KML text; a KMZ report also identifies the selected member and accompanying archive assets. This makes it possible to explain why a spreadsheet contains fewer geometric objects than a rich source map.
Inputs are limited to ten mebibytes and one hundred thousand supported vertices, with additional limits for workbook cells and archive expansion. A large file should be split by a documented feature or project boundary rather than truncated to a preview. Successful export means the supported content passed the stated checks; it does not certify the source survey or turn a visual map into an engineering control dataset.