# Viewport Lang > Set viewport and language - Skill: `whiteknightonhorse/viewport-lang` (Agent Skill) - Install (CLI): `npx skillmds@latest add whiteknightonhorse/viewport-lang` - Raw SKILL.md: https://api.skillmd.com/api/skills/whiteknightonhorse/viewport-lang/raw - Safety review: pending - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: Coding & Dev Tools - Author: whiteknightonhorse (https://skillmd.com/u/whiteknightonhorse) - Updated: 2026-09-17 - Page: https://skillmd.com/skills/whiteknightonhorse/viewport-lang --- # Set viewport and language > AIPUSH agent skill · Category: Content Structure · Slug: `viewport-lang` A viewport meta signals mobile-friendliness; `` declares content language. Both help crawlers, agents, and accessibility tools interpret your page correctly. ## Why it matters A viewport meta signals mobile-friendliness; `` declares content language. Both help crawlers, agents, and accessibility tools interpret your page correctly. ## How to detect Check for `` and a `lang` attribute on ``. ## How to implement ```html ``` Use the correct BCP-47 language tag (`en`, `en-US`, `de`, etc.). ## How to verify Rendered HTML has both a viewport meta and an `` value. ## References - https://developer.mozilla.org/docs/Web/HTML/Viewport_meta_tag --- Part of the [AIPUSH agent skills catalog](https://aipush.app/.well-known/agent-skills/index.json). Scan your site free at https://aipush.app.