Assembly Online Compiler
Write, compile, and run Assembly language code online directly from your browser using our free Online Assembly Compiler. Test NASM-style/x86 Assembly programs, view execution results instantly, and practice low-level programming without installing a local assembler, DOSBox, or emulator on your device.
How to Use This Assembly Compiler
- Write or edit your Assembly code
Enter your program in the Code Editor or modify the preloaded example. Make sure your sections, labels, instructions, registers, and directives follow the syntax supported by the compiler environment. - Click the Run button
Select Run to process and execute your Assembly program. If the code contains invalid syntax or unsupported instructions, review the reported error and update your program. - Review the Output screen
Your program result appears in the Output panel. You can copy or download the displayed output when needed, or use the delete option to clear it before another test.
Key Features
- Free Online Assembly Compiler: Write and run Assembly code from a web browser without setting up a local development environment.
- NASM-Style Assembly Support: Practice common Assembly concepts such as
.dataand.textsections, labels, registers, instructions, and system calls in the supported execution environment. - No DOSBox Installation Required: There is no need to configure DOSBox or a separate emulator locally just to test supported Assembly programs on this page.
- Instant Code Execution: Click Run and view the program result or compiler feedback directly in the Output screen.
- Dark and Light Mode: Switch the Code Editor theme for comfortable coding in different environments.
- Output Controls: Copy, download, or clear output directly from the Output panel.
- Code Download: Save your Assembly source code locally so you can reuse or continue working on it later.
- Beginner-Friendly Practice Environment: Useful for learning instructions, registers, memory concepts, labels, data declarations, and basic Assembly program structure.
1. Which Assembly architecture and syntax does this online compiler support?
This compiler is designed for NASM-style x86 Assembly syntax, including common constructs such as section .data, section .text, labels, registers, and Assembly instructions. The sample program shown in the editor uses instructions such as mov and the int 0x80 system-call convention.
Assembly code is highly architecture- and environment-specific, so instructions written for ARM, MIPS, MASM, or another platform may not work without modification.
2. Do I need to install DOSBox, NASM, or an emulator?
No local installation is required to use this Online Assembly Compiler. You can enter supported Assembly code in the browser, click Run, and check the result in the Output panel without configuring DOSBox or a separate assembler on your computer.
You may still need a local assembler or emulator if you are developing programs specifically for another operating system, processor architecture, or legacy DOS environment.
3. Why does my Assembly program show an error?
Assembly errors can occur because of an invalid instruction, incorrect register usage, missing label, malformed directive, unsupported system call, or syntax that belongs to a different assembler or CPU architecture.
Check the compiler feedback in the Output panel, correct the relevant instruction or syntax, and click Run again.
4. How do I clear or download my Assembly code and output?
Use the available Clear control when you want to reset the editor and start again. The Output panel also provides controls to copy, download, or delete the generated output. If you want to keep your source code for future use, use the available code download option to save a local copy.