A skill that makes Claude critique a design the way a senior art director does in a crit. You share a post, poster, pack, page, slide or screen. It first writes down what the piece has to do, for whom and at what size, and lists every element word for word. Then it gives the two-second read and works through hierarchy, layout and grid, type, colour, imagery, copy and accessibility. The three fixes that matter most come first, and each is precise enough to make without a follow-up question: which element, which property, from what value to what value.
Inside are five reference files: an eight-area checklist with figures and rules for nine formats, the WCAG 2.2, Apple, Android, Instagram and Meta figures with their sources and dates, a tested Python script that measures contrast, colours and edges and draws a marked-up image, a guide to writing redlines with unit conversions and type scales, and a full worked example for a fictional bakery. Every note is labelled as a standard, a craft rule or taste, and taste never makes the top three. It works one stage at a time and ends each with one question and a sensible default.
It reads images and PDFs, but it cannot open Figma or Canva links unless you have that connector switched on, so export at the real size. It sees one state of a design, so hover, motion and reflow stay untested, and it tells you so. Switch on code execution and contrast ratios, edges and gaps are measured instead of judged by eye, and you get a marked-up image with numbered pins. Tell it how finished the work is: concepts get notes on the idea and the hierarchy, final files get pixel-level notes. Send version two and it checks every note.
Claude skill · version 1.0
Design critique
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In the download · 9 files
- SKILL.mdThe method Claude follows: goal check, the critique with the top three fixes first, redlines, then the revision check, one stage at a time.
- README.mdHow to install it in claude.ai or Claude Code, how to start, and the licence.
- references/critique-checklist.mdThe eight-area checklist with figures and labels, rules for nine formats including social posts, packs and slides, and common problems with their usual fixes.
- references/standards.mdWCAG 2.2 figures, Apple and Android minimums, Instagram and Meta crops and safe zones, and poster viewing distances, each with its source and the date checked.
- references/critique-script.mdA tested Python script that measures contrast, colours and edges, makes squint, phone-size and mirrored views, and draws the marked-up image and wireframes.
- references/redlines-and-measuring.mdHow to write a redline, name elements, convert screen and print units, snap values to type and spacing scales, and say how accurate a measurement is.
Install it and begin
01Install it in Claude CodeTerminal mkdir -p ~/.claude/skillsunzip ~/Downloads/design-critique.zip -d ~/.claude/skills/# Start it with /design-critique. If this is your first skill, type /reload-skills once.On claude.ai there is nothing to unzip: upload the zip as it is. Every step is on Install and use a Claude skill.
02Your first message to ClaudeText Use the design critique skill. Here is [WHAT IT IS, FOR EXAMPLE AN INSTAGRAM POST] for [WHO IT IS FOR]. After seeing it, people should [THE ONE THING THEY SHOULD DO]. It is [EXPLORATION, REFINEMENT OR FINAL]. Give me the top three fixes first.Attach the design as a PNG, JPEG or PDF at its real size, plus your brand guide or the brief if you have them. Switch on code execution for measured contrast and a marked-up image.
Checklist
Before you send a critique
- The job is written as one sentence: after two seconds, who should know or do what.Every note is judged against it. A critique without a stated goal is a list of opinions.
- The top three fixes come first, blockers before polish, and none of them is taste.People act on the first three notes they read. A preference in that spot pushes out a real problem.
- Every note is labelled standard, craft or taste.The designer can see which notes are open to debate before the debate starts.
- Each measurement gives the number and says whether it was measured or judged by eye.A ratio of 2.33:1 settles a contrast question. A note that says the text is a bit light starts an argument.
- Contrast is judged at the size people see, not the size in the design tool.A 40 px bold line on a 1080 px post renders at about 14 px on a phone. WCAG 2.2 counts bold as large only from about 18.5 px, so it needs 4.5:1.
- Each redline names the element, the property, the old and new values, and where to measure from.If the designer has to ask how much bigger, it is not a redline yet.
- What works is named as precisely as what does not.Designers keep the decisions you praise by name and lose the ones you never mention.
What to do it with
- ClaudeFree tier, paid above it
A language model that writes, edits, reads long documents and runs tools, including agents that work inside a codebase.
Bad at It is agreeable by default, so it will improve a bad idea instead of telling you it is bad. Ask it to argue against you and the quality of the answer changes.
- Claude CodeSubscription
An agent that reads a whole repository, edits files, runs the tests and explains what it changed.
Bad at It is fast enough to make a large mistake quickly. Work on a branch, read the diff, and never let it push. Watch the starting mode: on Pro, Max and Team plans it opens in auto mode, which Anthropic's own list says may read a .env file and send the key in it to the API that key belongs to. Switch it off.
- FigmaFree tier, paid above it
The shared file where interface design happens: components, variables, prototypes and the handoff to code.
Bad at Its generative features make plausible screens rather than considered ones, and a plausible screen is the hardest kind to argue with in a review.
- CanvaFree tier, paid above it
Templates, brand kits and generation in one place, built so a non-designer can produce something acceptable.
Bad at Acceptable is the ceiling as well as the floor. Its templates are so widely used that a trained eye dates a deck in a second.
Tells you whether two colours are legible together, against the published standard.
Bad at The ratio is a floor and not a design. Passing text can still be unpleasant to read.
Why it matters
Ask a chat what it thinks of a design and you get a balanced list of soft opinions: make the headline pop, maybe add more white space. Nobody can act on that, and the one problem that stops the piece working sits among ten that do not matter. This skill makes Claude find the three changes that matter most, measure them, keep rules apart from preference, and write each fix as a redline a designer can make in minutes.
- Type
- technique
- Period
- ongoing