How to open .R files (R scripts) on Android, Windows and Linux

Your statistics tutor shares analysis.R, a research paper links its Julia code, or you’re curious about the Haskell exercises from a functional programming course. Without RStudio or the right compiler, the file won’t open on your phone, and Windows doesn’t recognise it either.

All of these are plain-text source files. Folders opens R, Julia, Elixir, Erlang, Clojure, Haskell, Elm, F# and OCaml files in its text editor on Android, Windows and Linux, so you can read the code, search it and make small changes.

What is a .r file?

A .r (or .R) file is a script in R, the language statisticians and data scientists use for analysis and charts. It grew out of the S language from Bell Labs and is free and open source. An R script is a list of commands: load a data file, fit a model, draw a plot.

R’s results are often saved separately, in .RData and .rds files. Those are binary data, not text; only the .R scripts are code you can read.

This guide also covers languages popular in research, finance and telecoms, many of them functional (built around functions and values rather than changing variables):

Extension	Language or format	What it’s for
.r	R	Statistics, data analysis and charts
.jl	Julia	Fast numerical and scientific computing
.ex	Elixir	Modules compiled into an app (Phoenix web apps, for example)
.exs	Elixir script	Scripts run directly: tests, config, mix.exs project files
.erl	Erlang	Source code for fault-tolerant systems, first built at Ericsson for telephone switches
.hrl	Erlang header	Records and macros shared between Erlang files
.clj	Clojure	A Lisp that runs on the Java Virtual Machine
.cljs	ClojureScript	Clojure that compiles to JavaScript
.edn	EDN (Extensible Data Notation)	Clojure’s data format, used for config such as deps.edn
.hs	Haskell	A pure functional language, built with the GHC compiler
.elm	Elm	A functional language for web front ends that compiles to JavaScript
.fs	F#	Microsoft’s functional language for .NET
.fsx	F# script	F# run directly as a script, with dotnet fsi
.ml	OCaml	Source code; OCaml comes from France’s INRIA research institute
.mli	OCaml interface	The public signatures of a matching .ml file

Elixir and Erlang share a runtime, the BEAM virtual machine, so Elixir code can call Erlang libraries directly.

How to open a .r file with Folders

On Android

1. Download Folders from the download section and install it. Your phone needs Android 7.0 or newer.
2. Open it and tap Allow access, then allow All files access.
3. Browse to the file, or use the search box. Course files usually land in Downloads.
4. Tap the file to open it in the text editor.

If the script came by email or chat, tap the attachment and choose Open with → Folders. Code shared as a ZIP opens in Folders like a folder.

On Windows and Linux

1. Install Folders: the setup program on Windows, or deb, rpm, AppImage, Flatpak, Snap or tar.gz on Linux.
2. Browse to the file in Folders and double-click it.
3. On Windows, Folders is also listed in File Explorer’s Open with menu for these types. Right-click the file and choose Open with → Folders.

What you can do with it in Folders

• Highlighting where Folders knows the language. R, Julia and Elixir files get colours for # comments, strings, numbers and keywords. Haskell and Elm get colouring for -- comments, strings and keywords such as where, let, data and module.
• Plain text with line numbers for the rest. Erlang, Clojure, EDN, F# and OCaml files open without colours, but with line numbers and every other tool below.
• Go to line. An R error points at a line in your script, and GHC reports Main.hs:23:5: error. Go to line takes you there.
• Find and Find and replace, with Match case, to rename a variable or find where a function is used.
• Edit and Save, with undo and redo, word wrap, and smaller or larger text for reading on a phone.
• Tabs, so an OCaml .ml file and its .mli interface, or an Erlang file and its .hrl header, can stay open side by side.
• Document info with the line and column, the encoding and the line endings.

Folders doesn’t run R or any other language here, and it doesn’t draw plots, evaluate code or type-check it.

Other ways to open .r files

• RStudio or Positron from Posit, for R; both are free desktop IDEs.
• Visual Studio Code with an extension for the language: Julia, ElixirLS, Ionide for F#, OCaml Platform, Calva for Clojure, and Haskell’s extension.
• The language’s own tools: Rscript analysis.R, julia script.jl, elixir script.exs, ghci for Haskell, dotnet fsi for F# scripts, utop for OCaml.

Problems opening a .r file?

• Your .RData or .rds file looks like gibberish. It’s saved R data in a binary format, not a script. Load it in R with load() or readRDS().
• A script works on Windows but not on Linux. Windows ignores upper and lower case in file names; Linux doesn’t. If the code says source("Helpers.R") and the file is helpers.R, it fails on Linux. Rename the file in Folders or fix the line.
• A .fs file isn’t F#. Graphics projects sometimes use .fs for OpenGL fragment shaders. If it starts with #version, it’s a shader. Either way, it opens as text.
• The script needs files you don’t have. R scripts load their data by path, with lines like read.csv("data/survey.csv"). If you were sent only the script, Find read. or load( to see which data files to ask for.

Questions people ask

How do I open an R file without RStudio? It’s a text file, so any text editor shows it. Folders opens it with highlighting on Android, Windows and Linux. To run it, you need R installed.

Can I open a .jl file on Android? Yes, to read and edit. Running Julia needs a computer with Julia installed.

.ex vs .exs: what’s the difference? Both are Elixir. .ex files are compiled into the project; .exs files are scripts run directly, which is why tests and config use them.

What is an .edn file? Clojure’s data format, a bit like JSON but with keywords, sets and comments. It isn’t JSON, so JSON tools won’t read it.

For Python and Jupyter notebooks, see how to open .py files. For Ruby, Perl and Lua, read how to open .rb files. And here are all 382 file types Folders opens.