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Compile and run Pascal code online instantly with HCODX. Our free cloud-based Pascal compiler supports real-time execution, standard input, syntax highlighting, and code download. No installation or configuration required. Start coding in Pascal now.
Run Pascal instantly without installing any IDEs or configuring environments. Our cloud-based Pascal handles libraries, runtimes, and dependencies automatically so you can focus on writing code.
Whether you are studying algorithms in Pascal, practicing data structures in Pascal, or exploring functional programming, our tool provides real-time stdout/stderr feedback with interactive standard input support.
HCODX is a free online compiler and code runner: write code in your browser, execute it on a cloud sandbox, and interact with your program through a live terminal. Students use it for coursework and interview practice; developers use it to test snippets in 85+ languages without setting up a local environment.
Niklaus Wirth designed Pascal in 1970 to teach structured programming, and it succeeded so thoroughly that a generation of programmers — and much of early Apple software — grew up on it. Turbo Pascal made it the definitive learning language of the 1980s-90s, and its lineage lives on commercially through Delphi and in open source through Free Pascal (the 3.2 series) with the Lazarus IDE; early Skype clients were famously built on Delphi. Pascal remains in classrooms today: several school systems and international olympiad traditions still teach it, prized for readable syntax and strict typing that catches beginner mistakes early. This page compiles Pascal and runs it in a live terminal where readln waits for your genuine keyboard input.
program InteractiveDemo;
var
name: string;
n, i: integer;
total: int64;
begin
write('What is your name? ');
readln(name);
writeln('Hello, ', name, '!');
write('Compute the factorial of: ');
readln(n);
total := 1;
for i := 2 to n do
total := total * i;
writeln(n, '! = ', total);
if total mod 2 = 0 then
writeln('The result is even.')
else
writeln('The result is odd.');
end.Pascal remains a set language in secondary-school computing curricula in several countries and a nostalgic-but-real skill for maintaining Delphi codebases, which still run point-of-sale, medical, and industrial software. Students use this page for homework — loops, procedures, records, arrays — without installing Free Pascal, and competitive programmers from olympiad traditions that permitted Pascal can warm up here. It's also a gentle first language for learners who benefit from begin/end blocks and compiler-enforced type discipline before moving to C or Java. HCODX is a free online Pascal editor, runner and interpreter — an IDE-grade compiler and playground to write and run code online, execute code with live output and live preview, no downloads or web server required.
Yes. readln suspends the running program until you enter a line in the terminal, and write output (like a prompt without a newline) is displayed first, so interactive programs behave exactly as in a local console. You can mix readln for strings and numbers across multiple prompts freely.
Programs are built with Free Pascal, the actively maintained open-source compiler, which supports classic Turbo Pascal syntax plus Object Pascal extensions and modern types like int64 and dynamic arrays. Textbook Pascal compiles unchanged, and most Delphi-style language features work in the appropriate mode.
No — this is a console environment, so Lazarus LCL forms and Delphi VCL units aren't available, and execution is a single source file. Standard units that ship with Free Pascal (SysUtils, Math, StrUtils) are usable, which covers essentially all coursework and console-program needs.
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