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Assembly to C Converter (Free AI Tool)
Convert Assembly to C for reverse engineering and binary analysis. Decompile x86, x64, and ARM assembly instructions to readable C code. Recover control flow structures (loops, conditionals), map registers to variables, and understand binary behavior without manual instruction-by-instruction analysis.
Paste code in both editors to see differences
Hint: Paste original code on left, modified code on right, then click Compare to see differences highlighted.
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Issue Description
Hint: Describe what you want to build or paste requirements, select target language, and click Generate.
How It Works
- 1
Paste Assembly Instructions from Disassembler
Input your x86/x64 or ARM assembly from IDA Pro, Ghidra, Binary Ninja, or objdump output. Include function prologues (push rbp, mov rbp rsp) and epilogues for better structure detection.
- 2
AI Performs Control Flow and Data Flow Analysis
The AI maps registers (EAX, RBX, R0, R1) to C variables, detects loop patterns from backward jumps (JNE to earlier address), identifies if/else from conditional branches (JZ, JNE), and recognizes function calls (CALL, BL instructions).
- 3
Review Decompiled C with Generic Variable Names
Receive C code with recovered control structures but generic naming (var1, var2, eax_val). Manual refactoring is needed for semantic variable names and comments. Use as starting point for understanding binary logic.
Assembly vs C: Abstraction Comparison
| Feature | Assembly (Low-level) | C (High-level) |
|---|---|---|
| Abstraction Level | Machine code, registers | High-level C constructs |
| Control Flow | JMP, JNE, CALL instructions | if/else, for, while loops |
| Variables | Registers (EAX, RBX, R0) | Named variables (int var1) |
| Memory | MOV [addr], direct access | Pointers, arrays |
| Readability | Low (1-to-1 with CPU) | High (human-readable logic) |
| Use Case | Binary analysis, debugging | Code understanding, porting |
Code Examples
Example 1: Simple Loop Recovery
mov ecx, 10 ; Loop counter
xor eax, eax ; Sum accumulator
loop_start:
add eax, ecx ; Add counter to sum
dec ecx ; Decrement counter
jnz loop_start ; Jump if not zero
ret// Decompiled C
int function() {
int ecx = 10;
int eax = 0;
while (ecx != 0) {
eax = eax + ecx;
ecx = ecx - 1;
}
return eax;
}Key Changes:
Assembly loop with backward jump (JNZ to loop_start) converts to C while loop. Register ECX maps to loop counter variable. Register EAX maps to accumulator variable. The DEC/JNZ pattern is recognized as a countdown loop. XOR EAX, EAX (zeroing idiom) becomes initialization to 0. The implicit return via EAX register becomes explicit return statement in C. Control flow is recovered from jump targets and conditional branches.
Example 2: Conditional Branch to If/Else
cmp eax, 0 ; Compare EAX with 0
jz zero_case ; Jump if zero
mov ebx, 1 ; True case
jmp end_if
zero_case:
mov ebx, -1 ; False case
end_if:
ret// Decompiled C
int function(int eax) {
int ebx;
if (eax == 0) {
ebx = -1;
} else {
ebx = 1;
}
return ebx;
}Key Changes:
CMP/JZ (compare and jump-if-zero) pattern converts to C if/else conditional. The JZ branch target (zero_case) becomes the if-true block. The fall-through code before the unconditional JMP becomes the else block. Register EBX is detected as the output variable assigned in both branches. The unconditional JMP to end_if is eliminated as C's block structure handles control flow implicitly. Labels (zero_case, end_if) are removed in favor of structured programming constructs.
Frequently Asked Questions
Architecture-specific SIMD instructions (SSE, AVX, NEON) may produce placeholder comments or inline assembly. Privileged instructions (system calls, interrupts), self-modifying code, and computed indirect jumps require manual analysis. Floating-point operations convert to C with potential precision differences. The tool focuses on standard user-mode x86/x64 and ARM instruction sets with common integer operations.
No. All assembly decompilation happens entirely client-side in your browser using JavaScript-based disassemblers and control flow analyzers. Your assembly code—whether from firmware dumps, binary analysis, or malware samples—never leaves your device. Zero network transmission occurs.
The converter achieves 85-90% accuracy for standard control flow patterns (for loops, while loops, if/else). Jump tables and switch statements are detected with 70-80% accuracy. Computed jumps, tail calls, and heavily optimized code may require manual refinement. Variable naming is generic (var1, var2) and needs semantic analysis for meaningful names. The output is a functional starting point for reverse engineering work.