Online Assembly Compiler

NASM (Netwide Assembler) is a popular x86/x86_64 assembler for Linux and Windows, with syntax that balances readability and direct access to CPU instructions. "Assembly" on this page means NASM-flavoured x86_64 — the same dialect taught in OS-development courses and used in CTF reverse-engineering challenges.

Assembling and linking a NASM snippet by hand requires nasm, ld, and a Linux sandbox — a heavyweight setup for a five-instruction experiment. A browser sandbox backed by our execution platform lets you assemble a snippet, dump machine code to stdout, and observe the program's exit code without touching a toolchain.

Operating-system development (bootloaders, kernel entry points, context switches), reverse-engineering Capture-The-Flag challenges, performance-critical inner loops, embedded firmware for resource-constrained microcontrollers, and security research (ROP chains, shellcode, format-string exploits). The sandbox runs NASM, links to ELF64, and invokes the program via direct Linux syscalls.

The default snippet exits with code 0 using the sys_exit syscall. Try replacing the mov rax, 60 with mov rax, 1 to switch to sys_write, or modify the mov rdi, rdi line to change the exit code. The highlighter recognises section .text, section .data, labels, the mov/syscall/int opcodes, and x86_64 register names.

An online Assembly compiler is a cloud-hosted editor and runtime that executes Assembly code directly in your browser — no SDK download, no interpreter install, no PATH configuration. See registers, stacks and arithmetic at machine level — ideal for coursework that maps source to execution. Everything runs inside an isolated sandbox: stdout and stderr stream back to the output panel in seconds, autosave keeps your work between visits, and a shareable URL hands the exact snippet to a teammate or interviewer. It doubles as a free Assembly interpreter for one-off checks.

If your stack mixes Assembly with C, the Online C Compiler keeps that context switch to one click. Run Assembly in the browser whenever an answer matters more than an environment — this page is a Assembly playground, a Assembly interpreter and a code runner in one tab. Working through Assembly exercises often spills into C++; the Online C++ Compiler answers in the same zero-setup style.

The workflow is deliberately short: paste or write Assembly code in the editor, hit Run (or press Ctrl+Enter), and read the output below. Trace a routine's register state and arithmetic step by step, the way architecture labs expect you to. Because compilation and execution happen in the cloud, you get the same result whether you are on a laptop, a lab machine or a borrowed Chromebook.

Working through Assembly exercises often spills into Zig; the Online Zig Compiler answers in the same zero-setup style. When you need more than one language, the full catalogue lives on the Online Compiler hub — every language runs on the same editor with the same instant output.

Assemblers and calling conventions differ per platform; the sandbox standardises one environment for practice. A local setup buys you package managers, GUIs and long-running processes — useful for shipping products, overkill for verifying a snippet. This free online Assembly compiler handles the everyday case: paste code, run, read output, share the link.

Working through Assembly exercises often spills into Zig; the Online Zig Compiler answers in the same zero-setup style. For practice across the whole catalogue, the free online compiler hub lists every language on one page.