So you've got an STL file and you want to make some changes to it? Whether you're a 3D printing enthusiast or a designer, being able to edit STL files online can be a game-changer for your projects. Luckily, there are several easy-to-use online tools that allow you to make modifications to STL files without the need for complex software or technical skills.

1. Tinkercad: Tinkercad is a popular online 3D design tool that supports STL file editing. It offers a user-friendly interface and a wide range of features that make it easy to modify and customize your STL designs. With Tinkercad, you can easily add, remove, or reshape parts of your STL files to fit your needs.

2. 3D Slash: 3D Slash is another great online tool for editing STL files. It provides a simplified and intuitive approach to 3D design and editing, making it perfect for beginners and experienced users alike. With 3D Slash, you can easily sculpt, paint, and modify your STL files with just a few clicks.

3. FreeCAD: FreeCAD is a powerful open-source parametric 3D modeler that supports STL file editing. While it may have a steeper learning curve compared to the previous tools, FreeCAD offers a wide range of advanced features for precise and detailed editing of STL files. It's a great option for those looking for more control and flexibility in their editing process.

4. Online STL Viewer and Converter: If you're looking for a quick and simple way to make basic modifications to your STL files, an online STL viewer and converter might be the solution. These tools often provide basic editing capabilities such as scaling, rotating, and mirroring without the need to download or install any software.

In conclusion, editing STL files online is easier than ever thanks to the variety of user-friendly tools available. Whether you're a beginner or an experienced designer, you can find the right online tool to help you make the changes you need for your 3D printing and design projects. Try out different options and see which one works best for you!