SolSec Labs is a web-based application that provides interactive training labs for blockchain developers, especially students eager to learn more about smart contract security to gain practical knowledge ( Fig. 1 ). It teaches solidity and smart contract security skills through hands-on experience. The easy-to-understand environment enables students and early developers to immediately apply newly learned secure coding practices to their ongoing projects. Currently, it consists of a total of 10 labs crafted using examples taken from the most severe real-world vulnerabilities. Every lab teaches developers about the related vulnerability; exploitation methods; preventive and remediation measures; and, finally, a step-by-step list of lab tasks to perform to secure the presented vulnerable code.