JOSM/Validator

The JOSM Validator is a feature of JOSM which checks and fixes invalid data. For a long time it was available as a plugin, but is now a core feature of the software. There is no longer any need to install these features as a plugin.

Usage

• Click on the new tick icon in the vertical toolbar to show the validator panel on the right.
• Select the data you want to validate (or deselect to validate everything)
• Click on the Validate button at the bottom of the validator panel

This will check the data and display all errors, categorized as errors, warnings, and other, depending on the severity of the error.

While some of the errors must be manually fixed, most of them can be automatically fixed. Just select the error or errors and click the Fix button to automatically fix them. You can select multiple errors, and all of them will be fixed.

Other usage tips:

• In preference settings, you can activate only the tests you need. By default, all tests are active.
• In preference settings, in the toolbar panel, you can include a validation icon in the horizontal toolbar at the top of the window (does the same as the Validate button on the right hand panel)
• The screenshot shows the validator panel undocked, in a separate window. Do this with the little pin icon if you need more space to see the errors tree.

Validations

These are the validations performed by the validator:

	Validation	Description	Fix
	Duplicated nodes	Checks that there are no nodes in the very same location	Merge the nodes into only one, adding the properties from all nodes to the merged one
	Duplicated way nodes	Checks that ways contain no loop edges (i.e., a single step from a node to itself)	Split the way, and delete the way consisting of the loop edge.
	Reversed coastline: land not on left side	Checks for coastlines that are not counter-clockwise or that are otherwise misplaced (coastline misused as inland lake)	Reverse coastline
	Unconnected coastline: coastline ways do not form closed loops	Checks for coastlines ways that are not connected to the end of other coastline ways
	Unordered coastline: coastline ways are not connected start-to-end	Checks for coastline ways of which either the start is not connected to the end of another coastline or the end is not connected to the start of another coastline	Reverse coastline
	Incomplete ways	Checks for ways with zero or only one node	Removes the way
	Check property keys	Checks misspelled property keys. See the User:JLS/speller page for information about misspelled property keys	Replace wrong key with right one
	Check property values	Checks misspelled property values. Uses the tagging presets file for checking	NONE
	Empty properties	Checks for properties with empty values	Remove the empty properties
	Crossing ways	Checks for ways (with highway/railway/waterway tags) that crosses in same layer with no crossing node	Add appropriate layer (and possibly bridge or tunnel)
	Unordered ways	Checks that all segments in a way are properly ordered	Reorder the way
	Overlapping (high)ways	Checks for two (high)ways that share the same nodes	Remove the double (high)way
	Self-intersecting ways
	Similar named ways	Checks for ways with very similar names, possibly a typo	NONE
	Unclosed ways	Checks that way types, which should be closed really are closed	NONE
	Untagged ways	Checks for untagged ways	NONE
	Way end node near other highway
	Style for outer way mismatches	Within a multipolygon relation, one of the tags of the relation and the outer ways is shared but with different values
	Style for inner way equals multipolygon	Within a multipolygon relation, one of the tags of the relation and the outer ways is shared and has the same value	Remove tag from inner way
	FIXMES	Checks for any property with the word "FIXME" inside	NONE
	Highway without a reference	Checks if there is a ref tag for highways that are tagged tertiary. Not always required, see for instance NL:Map_Features#Wegen	Add ref property or ignore
	Key 'x' invalid. - ...
	Nodes with the same name		NONE
	Overlapping areas
	Unknown property value	Checks for proper use of tags	Remove or change incorrectly used tag
	Untagged and unconnected nodes	Checks rogue nodes	Delete unused nodes when they have no further tags
	No style in multipolygon relation	The multipolygon relation is missing a tag describing what it is/represents	For a building, add building=yes to the relation etc. See also Relation:multipolygon

Wish list

Wishes for new features or bug reports should be reported at the BugTracker of JOSM.