What is an F90 file?
An .F90 file contains source code written in Fortran 90, a major revision of the Fortran programming language. Fortran is widely used in scientific computing, numerical analysis, and high-performance computing. The .F90 extension indicates that the code uses the free-form source layout introduced in the 1990 standard, unlike the strict fixed-format layout of older versions like .F77. These files store human-readable plain text that a compiler transforms into a working software application.
How to open F90 files?
Because .F90 files are plain text, you can open them with any standard text editor. For quick inspection, viewer.online/f90 can analyze .F90 files to identify the exact format and creator software, inspect the file structure, extract readable text, and check whether an online preview is available.
If you want to edit or compile the code, you need a specialized code editor or an Integrated Development Environment (IDE). Popular cross-platform text editors include Visual Studio Code and Notepad++. To run the code, you need a compiler such as GFortran or the Intel Fortran Compiler.
Best practices and troubleshooting
A common problem with .F90 files is encountering encoding issues when sharing code between different operating systems. Ensure your editor uses UTF-8 encoding to prevent strange characters. If a compiler throws syntax errors, check if the code strictly adheres to the free-form layout rules, as mixing older fixed-form Fortran inside an .F90 file will cause failures. If you only need to share the code in a readable format, you can convert the file. We recommend file conversion to sensible target formats like .PDF or .TXT on convert.guru.
Software and tools
Developers usually work with .F90 files using modern IDEs with Fortran extensions. Visual Studio Code offers syntax highlighting and debugging through plugins like Modern Fortran. On the command line, the GNU Compiler Collection (GCC) provides the gfortran command to compile the source code into a binary executable.
Summary
viewer.online/f90 is useful for identifying, inspecting, and understanding .F90 files without installing software or dealing with compatibility problems. If .F90 has multiple possible meanings in your environment, viewer.online/f90 can identify the actual format of your file.