Run Erlang online

Run Erlang OTP 26 online — the fault-tolerant BEAM VM, browser-hosted.

Available versions

Firecracker microVM live per-test verdicts multi-file compile

Erlang was built for telecom: nine-nines uptime, hot code reload, lightweight processes with per-process GC. Every property that makes it good at phone switches also makes it good at chat servers and payment systems.

ls-judge runs Erlang/OTP 26 through escript inside a Firecracker microVM.

Starter code

What you get in Erlang

Clicking "Run now" opens the playground with this exact code and a matching test case pre-loaded — passes on first Run.

erlang

Erlang 28

-module(solution).
-export([main/0]).
main() ->
    {ok, [N]} = io:fread("", "~d"),
    io:format("~b~n", [N * 2]).

stdin →

expected →

FAQ

Common questions about Erlang on ls-judge

Which OTP?: OTP 26.
escript or eshell?: escript — you write a module, we compile and run it.
Rebar3?: No — single-file compile only. External deps not fetchable.
Is it free?: Yes.