Generally, these files are created by a computer-aided design (CAD) program and are used in 3D printing technology. STL (stereolithography) is a file format, consisting of numerous triangular facets to generate a digital model and geometric shapes. However, most of them provide free models, allowing you to choose based on your needs and budget. These websites have active 3D communities and extensive repositories, offering both free downloads and paid model designs. We've collected a useful list of websites for you to obtain free STL files for 3D printing, listed in no particular order. These files can be used for making creative 3D projects and even for earning money. If you're a 3D printing enthusiast or a CAD designer, we believe STL files are indispensable in both your life and work.