What is a .FS file?
FS is a GLSL fragment shader - a small GPU program that computes the colour of every pixel a 3D surface covers.
- Did you know
- Fragment shaders run once per pixel, so a single full-screen effect can mean millions of invocations of the same .fs program every frame.
- GLSL, the OpenGL Shading Language these files are written in, has C-like syntax and arrived with OpenGL 2.0 in 2004.
- The .fs / .vs pairing is just one naming convention - the same code is also seen as .frag / .vert or bundled inside a single .glsl file.
- What Analyser reads
- Open and read programming-language source, build and configuration files as text: C, C++ and their headers, C#, Java, Kotlin, Go, Rust, Python, Ruby, PHP, Swift, Scala, Lua, Perl, R, Dart, Groovy and Visual Basic, GPU shaders (GLSL, HLSL), shell scripts (sh, Bash, Zsh, Fish), and the build and tooling files that fill a source repository - CMake, Makefiles, Ninja, Autotools (.in / .ac / .am / .m4), qmake projects, Doxygen configs and the dotfiles that configure Git, Docker, npm, ESLint, Prettier, Cursor and clang-format. Also opens Objective-C++ (.mm / .hmm), more GPU shaders (.fs / .vs / .gs), Boost.Jam and Meson build scripts, Unix manual pages, web stylesheets (Less, Sass/SCSS) and Svelte components, gettext translations (.po / .pot), Apple entitlements and licence/readme text, plus Cython (.pyx), OpenGL shaders (.fsh / .vsh / .geom), Git hook samples, ESLint and Yarn configs and ASP.NET (.aspx) pages. Each opens with a source preview, line count and metadata, entirely in your browser.
- Depth of analysis
- .FS is an identification-grade format: Analyser recognises it from its bytes and decodes the header metadata it carries, rather than opening it in a full viewer. Formats that do get a full viewer are marked "Full" on the formats page.
- Open a .FS file
- Drag a .FS file onto the Analyser home page (or tap to pick one). It is identified entirely in your browser - nothing is uploaded, there is no account, and it works offline once installed.