# Coordinate system transformation of value pairs on-line (cs2cs)

This on-line tool allows you to insert value pairs of geographic coordinates and transform them to different coordinate system or cartographic projection. You can insert value pairs to the text area labeled as "Input coordinate pairs" - also by using copy/paste even from MS Excell or similar programs. This tool accepts various input formats of value pairs - only what you need is to have one pair by a row. Please see examples in the input text area window.

It is necessary to set appropriate input coordinate system and to set desired output coordinate system to which you want to transform the input coordinate pairs. After you select a coordinate system, you will see so called "proj.4 text definition", which will be applied during the transformation process. If you want, you can edit it and change any parameter you want to change or you can insert your own definition you want to use.

### Input coordinate system / projection

Selected input coordinate system: **WGS 84 (EPSG:4326)**

Applied Proj.4 text:

### Input coordinate pairs

### Output coordinate system / projection

Selected output coordinate system: **Pseudo-Mercator (EPSG:3857)**

Applied Proj.4 text:

### Output coordinate pairs

**Beware!** Inserted values pairs needs to be in order X-coordinate and then Y-coordinate. If you are inserting latitude/longitude values in decimal format, then the longitude should be first value of the pair (X-coordinate) and latitude the second value (Y-coordinate). Otherwise you can use choice "Switch XY" below the input text area window.