Which C++ compiler is used?

GCC, running server-side, so errors and warnings match a normal local build.

Yes. The standard library is available, including containers, algorithms and iterators.

Can I split code across header and source files?

No. The playground compiles a single source file at a time.

main.cpp

Input

Output

Online C++ Playground

Runs on GCC 9.2.0 · Free · No signup required

A free online C++ playground and compiler for backend engineers. Write C++, compile it with GCC, and run it in your browser — no local toolchain, no build configuration, no signup. C++ has a long compile-edit cycle at the best of times, so removing setup entirely makes it far more practical to test a single idea. Use it to check how an STL container behaves, confirm what a template instantiates to, test iterator invalidation, or grind through algorithm problems for interview prep. Compilation runs server-side against real GCC, so the error messages you get are the genuine ones, template noise included. Standard input is supported for programs reading with cin. Programs compile as single files against the standard library. If you are practising data structures and algorithms for backend interviews, the playground connects to our DSA course and challenge arena.

C++ Playground — Frequently Asked Questions

Which C++ compiler is used?: GCC, running server-side, so errors and warnings match a normal local build.
Can I use the STL?: Yes. The standard library is available, including containers, algorithms and iterators.
Can I split code across header and source files?: No. The playground compiles a single source file at a time.

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