Accessibility and usability are both commonly used terms to refer to the satisfaction experimented by a user of a service or product. These two concepts are few used when referring to websites, though. To validate geoportal ONTORISK usability, this research proposes validated online tools as well as heuristic tests for measuring the accessibility level of expert users. According to the data analysis result, accessibility quantitatively presents a percentage of 73; and it qualitatively meets most of the established parameters. Regarding usability, the result shows percentages going from 40.23 percent to 73.64 percent. Finally, it was evidenced that applications can show an optimal operation. Nevertheless, they are not accessible or usable for all types of users since they do not meet the standards established by worldwide organizations.