Can I run R code online for free without installing it?

Yes. This compiler runs real R 4.x compiled to WebAssembly (the WebR project) directly in your browser. There is no signup, no install and no time-limited trial. Write a snippet, press Run, and read the console output and any plots — useful on a lab or library PC where you cannot install R or RStudio.

Is my R code uploaded to a server?

No. Execution happens inside a sandboxed Web Worker on your own device. Your source and data never leave the browser tab. After the one-time runtime download, you can open DevTools → Network and confirm that running code sends zero requests carrying your code.

How do I run R in the browser here?

Type or paste R into the editor (or pick a bundled example), then click Run or press Ctrl/Cmd + Enter. The first run downloads the R runtime once; after that it is cached. Printed values appear in the Console pane and any graphics appear in the Plot pane.

Can this online R tool make plots and graphs?

Yes. Base-R graphics — plot(), hist(), barplot(), boxplot() and friends — are drawn on WebR's canvas device and shown as images in the Plot pane. Each plotting call produces an image, so several plots from one run all appear. ggplot2 is not guaranteed in this version (see the package question below).

Why does the first run take a few seconds?

The first time you press Run, the browser downloads the R runtime and base image (about 30 MB) from the r-wasm CDN and starts it. That happens once — the files are cached, so later runs start quickly. A status line shows the loading progress so you know it is working.

Can I install CRAN packages like dplyr or ggplot2?

Only packages built as WebAssembly binaries (listed at repo.r-wasm.org) can be installed at runtime; packages needing native compilation or system libraries will not load. Base and recommended packages — stats, utils, graphics, datasets — work out of the box, which covers most teaching exercises.

Does the session remember my variables between runs?

Yes. Each Run reuses the same R global environment, so an object you assign in one run is still there in the next. Press Reset session to start a clean environment, or Reset to restore the example code. Pressing Stop on a long run also clears the session.

Is there a run-time limit or protection against infinite loops?

Each Run is capped at 25 seconds and executes in a Web Worker, so a stray while(TRUE) loop is stopped automatically and your tab stays responsive. You can also press Stop at any time. Console output is capped so a runaway print loop cannot freeze the page.

Is this good for university statistics courses in Sri Lanka?

Yes. R is the default teaching language for stats and research-methods courses at UCSC, Moratuwa, Peradeniya, Colombo and SLIIT. This is a zero-setup way to test summary(), lm(), a histogram or a data frame from any device — including a phone — without installing anything.

Developer · Runs in your browser

Online R Compiler — run R code in your browser

Write R and run it instantly, free, with no signup. It uses real R 4.x · WebAssembly (WebR), so vectors, summary(), data frames and base-R plots all execute in your own browser — your code is never uploaded.

By Induwara Ashinsana— Executive Director, Ryzera TechnologiesUpdated Jun 26, 2026

R code editorR 4.x · WebAssembly (WebR)

Example

Loading editor…

Ready

Console

Press Run to execute your R code. Printed values, warnings and errors appear here.

Plots

Base-R graphics — plot(), hist(), boxplot() — render here as images.

Runs entirely in your browser — your code is never uploaded.

How it works

This compiler runs WebR — the official build of R (the same R 4.x engine you would install from r-project.org) compiled to WebAssembly by the r-wasm project. When you press Run, your code executes inside a sandboxed Web Worker in your browser, not on our server. That makes it private (nothing is uploaded), effortless to scale (your device does the work), and unable to reach our systems or other users.

Because it is the real interpreter, results are identical to desktop R to the last digit. Functions such as mean(), sd(), summary() and lm() follow the definitions in the R language reference. For example, the quartiles in summary()use R's default type-7 sample-quantile rule (Hyndman & Fan, 1996): for a sorted vector of length n and probability p, it interpolates at position h = (n − 1)·p. The worked examples below were reconciled to that rule by hand and reproduced in TypeScript to confirm the engine's output.

Execution is captured through WebR's output API: standard output and standard error stream back to the page in the order R emits them, and top-level expressions auto-print exactly as they would in the R console (so a bare mean(x) prints [1] 6). Base-R graphics are routed to WebR's offscreen canvas device; each plotting call produces an image that is transferred to the Plot pane.

A few deliberate limits keep things safe and fast. The runtime and base R image (about 30 MB) are fetched only on your first Run, so the page itself stays light; after that they are cached. Runs reuse one persistent R global environment, so variables carry over between runs until you press Reset session. Each Run is wrapped in a 25-second timeout and an output cap — if code runs too long, the worker is terminated automatically and your tab stays usable, a guarantee you only get by running in a worker rather than on the main thread. Only packages published as WebAssembly binaries can be installed; native-compiled CRAN packages, local file access and network calls from R are out of scope in this version.

Worked examples

Vector and summary statistics

R input

x <- c(2, 4, 6, 8, 10)
mean(x)
summary(x)

Console output

[1] 6
   Min. 1st Qu.  Median    Mean 3rd Qu.    Max.
      2       4       6       6       8      10

Cross-checked in TypeScript with R's type-7 quantile rule — identical to base R's summary(): Min 2, 1st Qu. 4, Median 6, Mean 6, 3rd Qu. 8, Max 10. Mean = (2+4+6+8+10)/5 = 30/5 = 6.

A base-R histogram

R input

v <- c(5, 7, 7, 8, 9, 9, 9, 10, 12, 14)
hist(v, main = "Distribution of v", col = "steelblue")

Console output

(no printed value — hist() returns invisibly; the chart appears in the Plot pane)

The Plot pane renders the histogram with the given title and fill colour. Here n = 10 and the mean is 90/10 = 9; the value 9 occurs three times, so the tallest bar sits over the bin containing 9.

Errors and unavailable packages (edge case)

R input

summary(lm(dist ~ speed, data = cars))   # works: a built-in dataset
library(tidyverse)                       # not a WebAssembly binary

Console output

Call:
lm(formula = dist ~ speed, data = cars)
...
Error in library(tidyverse) : there is no package called 'tidyverse'

The model on the built-in cars dataset runs normally, then the missing-package error is shown in red in the Console pane — not swallowed. Built-in datasets and base/recommended packages are available; packages without a WebAssembly build are not.

Frequently asked questions

Sources & references

Execution is the unmodified R interpreter via WebR WebAssembly; only the editor and worker glue are custom. The worked-example outputs were last cross-checked against R's published definitions on 2026-06-26.

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Comments & feedback

Spotted a bug or want an improvement? Tell us — our team reviews every comment, and good ideas get built. Comments are public and anonymous.

Found a bug, an edge case, or want another language added?

Email me at [email protected] — most fixes ship within 24 hours.