February 23, 2026
When CSS cosplays as a CPU
Show HN: X86CSS – An x86 CPU emulator written in CSS
CSS runs a vintage PC brain — the internet yells “Abomination!” then claps
TLDR: A developer made an old-school PC processor run using only CSS, no JavaScript, and it actually works. Commenters are split between calling it a pointless “abomination” and cheering the creativity, with jokes about AI, hopes for broader browser support, and a side of security paranoia fueling the spectacle.
Someone just crammed a vintage PC brain (the old 8086 chip) into pure CSS — no JavaScript — and the internet lost its mind. The demo actually runs compiled C code inside stylesheets, and the comment section instantly split into two camps: the why would you do this crowd and the this rules art kids. One critic summed up the collective whiplash: “There is absolutely no reason for CSS to be turing complete… well done.” That’s the vibe — disgust and admiration doing a tango.
Browser drama arrived fast. Right now it works best in Chrome-like browsers, and one commenter is already eyeing wider support once a new CSS feature lands, hoping Firefox joins the circus soon (link). Security panic? A bystander lobbed in a spicy thread about a fresh CSS zero‑day, sprinkling paranoia over the party (link).
Meanwhile, the jokes flowed. One dev joked they’re safe from AI replacing their job because, let’s face it, making a CPU in CSS is a hobby from another planet. Another commenter performed a mock exorcism — “Abomination!” — before confessing they were impressed.
The creator admits it’s not practical, just joyful chaos: a proof that CSS can compute with zero clicks and zero scripts. Is CSS a programming language? After this, the crowd’s answer is: it shouldn’t be… and yet, apparently, yes. Welcome to the weird, wonderful web.
Key Points
- •x86CSS runs 16-bit x86 (8086) machine code compiled from C entirely within CSS, without requiring JavaScript.
- •A script tag can provide a clock for speed and stability, but a JS-less clock using CSS animations and container queries is available and functional.
- •The emulator’s CSS-based CPU does not need HTML markup, though a style tag is needed; the demo currently works only in Chromium-based browsers.
- •Most required x86 instructions are implemented based on GCC-compiled program needs, but some behaviors (e.g., CF/OF flag setting) are missing or incorrect.
- •Users can write and run their own programs by compiling them themselves; direct CSS programming is faster than emulating a CPU.