Struct Memory Layout Visualizer

Visualise byte-level memory layout of C, C++, Rust, or Zig structs. Shows field sizes, byte offsets, and alignment padding highlighted in red.

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Struct layout in C, C++, Rust, and Zig is governed by alignment rules that can insert unexpected padding bytes between fields — wasting memory, creating security vulnerabilities in serialised formats, or causing bugs in binary protocol implementations. The Struct Memory Layout Visualizer takes a struct definition and shows a precise byte-level diagram with each field's size, offset, and any alignment padding highlighted.

Systems programmers and embedded engineers who need to understand or optimise their struct layouts — whether for memory efficiency, binary protocol design, or debugging a subtle alignment bug.

01 Open the Struct Memory Layout Visualizer on Doathingy.com
02 Paste your struct definition
03 The byte-level layout diagram appears immediately
04 Red highlighted bytes show alignment padding

No tutorials. No learning curve. Open it and get started.

No server uploads. Alignment padding is highlighted separately — so you can immediately see where memory is being wasted and which field is causing it.

Completely free. No trial period. No premium tier for basic functionality. No account required. Use it as often as you need.

One job, done well. Struct Memory Layout Visualizer was built to solve a specific problem cleanly. No feature bloat, no ads, no distractions.

What is struct padding?

The compiler inserts unused bytes between fields to ensure each field is aligned to its natural alignment boundary, which may waste memory.

How can I reduce padding?

Order fields from largest to smallest type — this often minimises padding. Use #pragma pack or __attribute__((packed)) for packed structs.

What is alignment?

A type's alignment requirement — the address of the field must be divisible by this value. int is typically 4-byte aligned.

Does this support nested structs?

Common struct definitions including nested types may be supported.

Why does my 24-byte struct only need 20 bytes?

The extra 4 bytes are alignment padding — reordering fields may eliminate it.

Free. Instant. No sign-in. Open it and get the job done.

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