This book constitutes the proceedings of the 15th International Conference on Tests and Proofs, TAP 2021, which was held as part of Software Technologies: Applications and Foundations, STAF 2021, and took place online during June 12-25, 2021.The 6 full papers included in this volume were carefully reviewed and selected from 10 submissions. They were organized in topical sections on learning, test resource allocation and benchmarks and on testing.

This book constitutes the proceedings of the 15th International Conference on Tests and Proofs, TAP 2021, which was held as part of Software Technologies: Applications and Foundations, STAF 2021, and took place online during June 12-25, 2021.The 6 full papers included in this volume were carefully reviewed and selected from 10 submissions. They were organized in topical sections on learning, test resource allocation and benchmarks and on testing.