What is a JL file?
A .JL file usually contains source code written in Julia. This is a high-performance programming language. Developers use it for numerical analysis and computational science. A Julia Source Code File stores instructions in plain text.
Another very common use for the .JL extension is a JSON Lines data file. These files store structured data. They contain one valid JSON object per line. Less frequently, a .JL file might be a Pluto interactive notebook, an image file used by ImageJ, or a script for the Phoenix Jailbreak tool.
How to open JL files?
Because a .JL file has multiple possible meanings, you must identify the correct format before opening it. viewer.online/jl analyzes .JL files to identify their exact format and creator software, shows which programs can open the file, and usually previews it.
You can open a Julia Source Code File using standard code editors like Visual Studio Code or Notepad++. You can also run them in the Julia command-line environment. JSON Lines data files can be opened by text editors or parsed by data analysis scripts.
Software and tools
If your file is a source code file, we recommend Visual Studio Code with the official Julia extension. If your file is a Pluto interactive notebook, use the Pluto.jl package within Julia. For the rare 16-bit integer image files, you will need ImageJ or VXL Computer Vision Libraries.
Best practices and troubleshooting
Sometimes you need to share your data or code in a different format. We recommend file conversion to sensible target formats on convert.guru. For example, you can convert a JSON Lines .JL file to a standard .JSON file or a .CSV file.
Summary
Because .JL files use the known JSON format, viewer.online/jl can safely open and display them online, eliminating compatibility problems.