Tiny Binaries

A collection of assembly programs crafted for extremely minimal executable size.

⚠️ Unsafe - Educational Use Only

These binaries are unsafe as a consequence of extreme size optimization. They:

• Skip all error handling on syscalls—failures are silent with no indication
• Have no bounds checking or input validation—no protection against malformed input or buffer overflows
• Assume specific kernel and CPU behavior (register state, ELF loader specifics)—will crash or misbehave if assumptions don't hold

These are proof-of-concept explorations of manually written assembly. Do not use in production or any real-world context.

Why?

A regular hello world program in C compiles to ~14 kilobytes. This project explores how small we can make these binaries through assembly optimization—a fun challenge in understanding the costs of abstraction.

How?

Size reductions are achieved through:

• Minimal structure - Skip C runtime startup, dynamic linking, and metadata sections (e.g., .dynamic, .got, .eh_frame, .note.*)
• Direct syscalls - Calling the kernel directly instead of going through libc wrappers
• Minimal code - Only essential instructions, no loops or conditionals unless necessary

The ELF format requires ~84 bytes minimum (ELF header + program header). The rest is code and data.

Result: hello-world in 115 bytes total vs. 14 KB—a 122x reduction.

Requirements

Each tiny binary must meet these constraints:

• Functional correctness - Must perform the program's intended function (e.g., exit code for true, output for yes, file reading for cat). Side effects don't matter (e.g., hello-world exits with code 1, not 0)
• Platform compatibility - Must run on 32-bit x86 Linux or x86-64 Linux with IA-32 support
• Valid ELF executable - Must be a valid ELF binary (not DOS COM, PE, or other formats requiring emulation)
• No external dependencies - Must be fully self-contained (no libc, no runtime libraries)
• Single executable file - Must be a single binary file with no external scripts or support files
• Direct syscalls only - Cannot use libc wrappers; must call syscalls directly
• Minimize size - Binary size is the primary optimization goal

Prerequisites

• NASM
• GCC
• GNU make

Status

Program	Status	Bytes
hello-world	✅	115
true	✅	87
yes	✅	102
factorial	⏳	-
fibonacci	⏳	-
echo	⏳	-
date	⏳	-
simple HTTP "Hello" server	⏳	-
GNU Coreutils	⏳	-

Build & Test

# clone the repo
git clone https://github.com/AlphaLynx0/tiny-bins.git
cd tiny-bins/hello-world

# assemble, compile, and compare both versions
make savings

Each subdirectory follows the same pattern:

• make builds both the ASM and C versions
• make listing shows the assembly instruction breakdown with byte offsets and sizes
• make savings compares their sizes
• make test (if implemented) tests the output of ASM and reference binaries
• make clean deletes binaries and listing files

License

MIT © AlphaLynx alphalynx@alphalynx.dev