Scratch/Online and Offline Editors

The Scratch editor is available both online and through standalone applications. Deciding which editor to use largely depends on what you plan to do with Scratch and the requirements of your hardware setup. Links and requirements of the official editors can be found on the page Scratch/Lessons/Downloading

The Online Editor
Scratch's online editor has several advantages over the offline editor. It can run in a web browser, so installing additional software isn't required and it takes up no space on your hard drive. This also makes it excellent in situations where you can't install software, such as on public computers. If you've made an account on Scratch's website, your project will be saved to their servers. However, it also has some downsides. It cannot be used without an active internet connection, and it can only be used for the latest version of Scratch.

The Offline Editor
The offline editor allows for developing projects without an internet connection. As a standalone application, it requires between 360 and 75 megabytes depending on your operating system. It also lacks a few features from the online editor, namely the backpack, cloud variables, and some accessibility options. However, the offline editor is one of the only ways to use older versions of scratch such as Scratch 2.0 and Scratch 1.4. These older versions also offer a method to directly upload a project to your Scratch account, but the Scratch 3.0 editor currently lacks this feature, so projects have to be uploaded to the website.

Third-party Editors
While this Wikibook is focused on only the official Scratch editors, several unofficial editors also exist. These editors can expand Scratch's functionality to add highly requested features such as 3D or improve on the editing experience through additional features. They may also improve the performance of projects by compiling them to Javascript. However, these editors aren't without their disadvantages. Like the Scratch 3.0 offline editor, no third-party editor can directly upload to Scratch. Additionally, if you use features of these editors that aren't present in Scratch, you won't be able to upload your project. Lastly, editors that compile to Javascript can not have edits made while the project is running. As well, the benefits to performance from compiling are usually only noticeable in highly advanced projects, which means that most devices don't need them to comfortably run the vast majority of projects.