Loading…

Online C++ Compiler and Playground

Browser-based compiler and playground for C++ — Progsity IDE.

About C++

C++ adds classes, templates, the STL, and RAII to C—making it the backbone of game engines, browsers, and high-frequency systems. This online C++ compiler is a lightweight way to try std::vector, iostreams, and algorithms without setting up a toolchain on every machine.

When you run code, you compile with a modern GCC-compatible toolchain in a sandbox. You will see compile-time errors clearly, which is essential while learning move semantics, smart pointers, and overload resolution.

Use stdin for competitive-style problems or CLI tools. Save snippets when logged in so you can iterate on contest templates or share a link with your study group.

How to use

  1. Start from the default main() that uses std::cout. Include headers you need, such as <vector> or <algorithm>.
  2. Paste competitive input into stdin if your program reads with std::cin.
  3. Read compile errors in the output panel; fix includes and typos, then Run again.

FAQ

Is this online C++ compiler free?›

Yes for running code. Saving many snippets may be subject to account limits on the free tier.

Can I use C++17 or C++20 features?›

The backend uses a recent GCC build; many modern features work. If something fails, simplify or check compiler flags in documentation.

Can I save my C++ programs?›

Yes after sign-in. Open them from your dashboard under Playground.

Why do I get compile errors?›

Missing semicolons, wrong namespaces, or template errors are common. Read the first error message carefully—it often fixes the rest.

Playground vs full IDE?›

This is a playground: single file, run, inspect output. No CMake, no multi-file projects yet.

Related languages

Code examples

Tap “Try this” to load sample code into the editor above.

  • std::vector sort

    #include <iostream>
#include <vector>
#include <algorithm>

int main() {
    std::vector<int> v = {5, 2, 8, 1};
    std::sort(v.begin(), v.end());
    for (int x : v) std::cout << x << " ";
    std::cout << "\n";
    return 0;
}

  • Read a line

    #include <iostream>
#include <string>

int main() {
    std::string line;
    std::getline(std::cin, line);
    std::cout << "Length: " << line.size() << "\n";
    return 0;
}

  • Simple struct

    #include <iostream>

struct Point {
    int x, y;
};

int main() {
    Point p{3, 4};
    std::cout << p.x + p.y << "\n";
    return 0;
}

  • Range-based for

    #include <iostream>
#include <vector>

int main() {
    std::vector<int> v = {1, 2, 3};
    int s = 0;
    for (int x : v) s += x;
    std::cout << s << "\n";
    return 0;
}