# Visual Proof > Capture before/after screenshot evidence of a web page at real breakpoints (375, 768, 1440) in both light and dark themes, using Playwright against a local dev server or a deployed URL. Use before starting any visual change to capture the current state, and again after to prove the delta. Also use when asked to "show me what it looks like", check responsive behavior, verify dark mode, or confirm a layout does not break on mobile. Reports honestly when a browser or server is unavailable rather than describing a page it never rendered. - Skill: `frankxai/visual-proof` (Agent Skill, multi-file: 2 files) - Install (CLI): `npx skillmds@latest add frankxai/visual-proof` - Raw SKILL.md: https://api.skillmd.com/api/skills/frankxai/visual-proof/raw - Safety review: pending - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: Coding & Dev Tools - Author: frankxai (https://skillmd.com/u/frankxai) - Updated: 2026-09-17 - Page: https://skillmd.com/skills/frankxai/visual-proof --- # Visual Proof Screenshots are the only claim about a page's appearance that cannot be hallucinated. Capture before you change anything, and after. If you cannot capture — no server, no Chromium, no network to the deployed URL — **say so and stop making visual claims.** Describing a page you never rendered is the single most common way UI work goes wrong undetected. ## The matrix Six shots per state. Not one, not a single desktop hero crop. | Width | Stands for | |---|---| | 375 | phone — where layouts actually break | | 768 | tablet / the awkward middle breakpoint | | 1440 | desktop | × light and dark, if the site ships both themes. ## Run it The pack ships a runner. From the repo root: ```bash # against a local dev server node .claude/skills/visual-proof/capture.mjs --url http://localhost:3000/ --label before # ...make the change... node .claude/skills/visual-proof/capture.mjs --url http://localhost:3000/ --label after # or against a deployed preview node .claude/skills/visual-proof/capture.mjs --url https://.vercel.app/pricing --label after ``` Output lands in `.visual-proof/