What are common causes of WKT syntax errors?

The most common WKT errors are unclosed polygon linear rings (first and last coordinate must match), commas between longitude and latitude pairs, insufficient points for LineStrings (minimum 2), and mismatched parentheses.

How does Spatial-Sandbox validate PostGIS WKT?

Spatial-Sandbox uses standard OGC Simple Feature Specification (SFS) parsers to check geometric validity, coordinate syntax, nesting level, and closed polygon boundaries in real-time.

CRS / Projection

Enter an EPSG code to set the input CRS of your geometry data (e.g. EPSG:3857 for Web Mercator, EPSG:27700 for British National Grid). Geometries are automatically reprojected to WGS84 (EPSG:4326) for display on the map.

Free Online WKT Validator & Syntax Checker

Validate Well-Known Text geometry syntax, detect coordinate anomalies, verify polygon outer and inner ring closure, troubleshoot PostGIS spatial queries, and render compliant geometries on interactive maps.

Common WKT Syntax & Formatting Errors

The validator checks for common spatial data parsing pitfalls:

POLYGON((0 0, 10 0, 10 10, 0 10)) ← Missing closure First & last coordinate must match

LINESTRING(0 0) ← Insufficient points Must contain ≥ 2 coordinate pairs

POINT(72.57, 23.02) ← Comma between coordinates Space separates X & Y, comma separates vertices

Correct Syntax Templates

Test these compliant WKT strings directly:

POINT(2.2945 48.8584)

LINESTRING(-122.4786 37.8100, -122.4783 37.8199, -122.4780 37.8300)

POLYGON((-73.9731 40.7644, -73.9579 40.7972, -73.9818 40.8005, -73.9819 40.7681, -73.9731 40.7644))

Online WKT Viewer & Plotter →

Full WKT geometry visualizer with style manager, layer toggle, and CRS reprojection.

Online GeoJSON Viewer & Visualizer →

Inspect GeoJSON FeatureCollections, property tables, and map styling.

In-Depth WKT Specification & Troubleshooting Guide

Having trouble resolving invalid geometries, self-intersecting linear rings, or coordinate dimension errors? Read our comprehensive technical guide:

👉 The Definitive Guide to Well-Known Text (WKT) Geometry →