Online ontology and thesaurus matching, mapping validation and alignment evaluation

Yam++ Online is a web tool for ontology and thesaurus matching, with an interface for human validation of the generated mappings.
It uses the Yam++ Large Scale library to perform the matching. This library is published under the GPL3.0 license


Takes as an input ontologies in different formats (owl, skos, and various serializations of rdf, such as ttl) and produces alignments in a format of the user's choice.

K. Resources

Contains a set of Knowledge Resources shared by YAM++ users: Ontologies and Reference Mappings or Simple Mappings can be accessed and downloaded from this page.


Takes as an input an alignment in AlignmentAPI RDF format, visualises it together with the degree of confidence of each mapping and lets the user confirm, reject or mark as uncertain each of the produced mappings. The modified alignment can be stored in one of the possible alignment formats.


Computes measures about an alignment given a reference alignment : precision, recall and f-measure.

Matcher API

A HTTP API to get an alignment between 2 ontologies. You can pass the URL of the ontology with "sourceUrl" and "targetUrl" parameters.