Assembler Playground

Assemble Intel x86 and x86-64 instructions online. Inspect exact bytes and instruction boundaries, download raw output, or hand it to disassembly and emulation tools.

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Turn readable assembly into exact bytes

Write Intel-style x86 or x86-64 source with labels and assemble a documented portable subset covering register moves, arithmetic, stack operations, calls, jumps, interrupts, syscall instructions, and raw-byte directives.

Each source instruction is paired with its address, encoded bytes, and boundary. Unsupported syntax fails with a line-specific error instead of being ignored or guessed.

Continue in Binary Lab

Download raw machine code or save it as a local artifact, then inspect it in the machine-code disassembler, hex editor, diff tool, or constrained shellcode emulator.

Frequently Asked Questions

Is this a complete production assembler?+

No. It is a deterministic, documented Intel x86/x64 subset intended for learning and small analysis snippets. Unsupported instructions stop with an error.

Can I use labels?+

Yes. Relative calls, jumps, and conditional jumps can target labels or numeric addresses. The output table shows each final instruction boundary.

Can I inspect the generated bytes?+

Yes. Copy or download the raw bytes, or save them to Binary Lab and hand them to the disassembler, hex editor, binary diff tool, or shellcode emulator.

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This tool is provided for informational and educational purposes only. All processing happens in your browser — no data is sent to or stored on our servers. While we strive for accuracy, we make no warranties about the completeness or reliability of results.