The Slop Detector That Couldn't Design Its Own Landing Page

All three before/after case studies on impeccable.style made the design worse. That was the near-unanimous verdict of the Hacker News thread on 12 January, 103 points and 64 comments, most of them unkind. Which is a difficult result for a tool whose entire pitch is fixing design.

The specifics were worse than the summary. On the landing page, fxtentacle wrote: “You start with a page that has usage numbers, uptime, support 24/7 and a customer rating above the fold. You end up with a page that lacks all of these advantage and instead looks bland and has horrible typography and even less text contrast.” On the signup form, lelandfe: “It took a streamlined form used to convert and added enormous marketing copy that’s more attention grabbing than the form itself. And this is what the creator chose to demo.” b450, who has run A/B tests on signup forms, said they’d bet money the redesign converted worse.

Meanwhile the site itself was broken. The before/after container stopped scrolling with the page, leaving a blank void. ninalanyon offered a definition: “impeccable (adj.) Of user interface style: low contrast and hence poor readability, with excessive white space.”

What happened next is the interesting part

Paul Bakaus, who built jQuery UI and ran product for Chrome DevTools, showed up and replied to essentially every critic. He didn’t submit the link himself, so he walked into this cold.

His answers were unusually direct for an OSS launch. On the examples, replying to fxtentacle: “I wasn’t happy with the outcome of those before/after examples, it was rushed before the launch, and I shouldn’t have shipped it. Removed. I mostly use these commands on smaller targeted sections on projects that I unfortunately can’t screenshot.” He removed all three. On the marketing copy, answering the vocabulary critique: “I toned down some of the language on the landing page, as it had sometimes too much snake-oil-salesman-energy, should not oversell.” The broken scroll container was a one-line CSS mistake he fixed the same day. The dark theme got deleted outright: “Agreed. Removed.”

Six months on, the removed case studies have been replaced by Neo Mirai, a conference site built from a generated hi-fi mock through to shipped, responsive HTML, with the live build linked so you can judge it yourself. The repo now carries 23 commands and a detector covering 64 patterns. Fifty-nine of those are deterministic rules, no LLM and no API key involved: the plain npx impeccable detect handles the ones readable from source, while rules that need real browser layout run via Puppeteer or the extension. Five broader judgments are left to the LLM critique. Downloads say people are using it: 266,021 npm installs in the month to 23 July, 72,156 in the last week alone.

Does the vocabulary actually do anything

The strongest evidence comes from outside the project. Tessl ran quality benchmarks across three scenarios (revenue dashboard, landing page, task manager) and, as reported by paddo.dev in March, scored an 0.82/1.00 aggregate with the skill active, a +0.35 improvement over baseline. OKLCH colour usage went from 0 to 12 out of 12. A 1.59x lift from injecting vocabulary, with no model upgrade involved. Paddo raises the obvious caveat: the benchmark measures what Impeccable optimises for, which makes it somewhat circular.

The more convincing result is the boring one. Running /impeccable audit on paddo’s own site caught 18 issues they’d missed: missing alt text on hero images, no skip-to-content link, zero prefers-reduced-motion handling, broken focus states. None of that is taste. It’s a linter finding defects, and a linter that finds 18 real accessibility bugs has already paid for itself.

Impeccable versus Taste Skill

Taste Skill is the bigger repo by stars: 67,340 since 19 February, against Impeccable’s 49,760. It takes a different shape, offering installable SKILL.md variants (minimalist, brutalist, soft, redesign-existing-projects) plus three dials at the top of the file, DESIGN_VARIANCE, MOTION_INTENSITY and VISUAL_DENSITY, each on a 1 to 10 scale. The default skill is currently v2 and labelled experimental. Among its rules is a hard ban on em dashes, which this blog can only endorse.

Star counts are a poor proxy for adoption here. Taste Skill’s Hacker News submission in May drew 3 points and zero comments, and the README carries a disclaimer that no crypto token is associated with the project, which tells you what kind of attention 67k stars attracts.

Impeccable wins on the parts that are checkable: a deterministic detector, browser-based iteration, and a design contract that adapts rules to your project instead of imposing generic defaults. /impeccable init writes a PRODUCT.md and offers a DESIGN.md recording audience, voice, anti-references, colours, type and components, and every later command reads them, which is what keeps multiple pages coherent. Taste Skill wins if you want a preset visual direction with one command and a dial to turn.

The moving target objection, answered

The obvious criticism is that “AI slop” means the 2025 look, models improve, and these rule sets are fighting a battle that ends on its own. Bakaus built the answer into the product. The detector page has an era toggle: flip to 2022 and you get purple gradients, glassmorphism and neon glow; flip to 2026 and the tells have changed while the underlying failure has not. “Every wave of AI-generated UIs converges on a recognizable aesthetic,” the page says. “The patterns just change.”

The surrounding category has gone slightly silly. 21st.dev, which the current crop of tutorial videos recommends alongside these skills, started as a Show HN in December 2024 pitching “NPM for Design Engineers Based on Shadcn CLI” and today leads with animated heroes, shaders, liquid metal and gradients. The anti-slop stack and the slop supply chain are selling to the same person. Yesterday’s entry, “Turn Claude Into A Design GENIUS In 3 Simple Steps” from Chase AI, did 73,000 views in a day and closes with a pitch for the presenter’s Claude Code masterclass.

Vocabulary is the cheap part

The top comment on the January thread was Antibabelic’s, and it still holds: “Vocabulary is just the surface. Beneath it is an understanding of how to achieve your goals with design.” Knowing the phrase “vertical rhythm” gets you a better prompt. It doesn’t tell you when the answer is to delete the section. There’s a sharper worry in the No Skill. No Taste thread from February, 203 points and 208 comments on this exact question, where roywiggins argued that heavy generative AI use degrades your own judgment: you spin the wheel a thousand times, and by the time one output looks good you’ve recalibrated downward to notice.

So install Impeccable, run /impeccable audit, and take the accessibility findings seriously, because deterministic rules catching real defects is a solved and useful thing. Treat /critique as a second opinion from a stranger with strong feelings about bounce easing. The part of the workflow that actually improves your output is the part every one of these videos races past in ninety seconds: look at what you built, decide whether it’s good, and be able to say why.

Sources: Impeccable on Hacker News · pbakaus/impeccable · The slop catalogue · Neo Mirai case study · Leonxlnx/taste-skill · paddo.dev on the vocabulary layer · Developers Digest on taste skills as infrastructure · No Skill. No Taste

Related: Ralph Is Five Lines of Bash · The Managed Agents Landscape · Option-Shift-Hyphen: The Em Dash as LLM Tell