End-to-end internationalization and localization documentation for developers who ship in more than one language.

🌐 Live site: www.i18n-l10n.com

Internationalization is one of those things that looks simple until the first bug report comes in from a locale you never tested — a plural that reads wrong in Polish, a date that lands a day off in Tokyo, a translation catalog that silently drops half its keys after a one-character source edit. i18n-l10n.com is a practical, deeply technical reference for getting all of that right: 51 hand-written guides covering the full path from resolving a user's locale to keeping translations in sync through your CI/CD pipeline.

Every page is written for engineers doing the actual work — real code, real failure modes, real fixes — not marketing fluff. Diagrams are hand-authored SVGs, examples are runnable, and the hard edge cases (CLDR plural categories, ICU selectordinal, RTL mirroring, redirect loops in Next.js middleware) get the space they deserve.

The guides are organized into three areas that follow the work itself:

The foundational layer — how to make locale handling deterministic and correct.

• Locale negotiation strategies and fallback chain configuration
• ICU Message Format in depth: nested plurals, select/selectordinal, complex messages
• CLDR pluralization rules across languages (including Arabic and Slavic few/many traps)
• Date & number formatting with the native Intl API
• RTL / bidirectional layout engineering
• Translation memory & glossary management

Framework-specific integration patterns for the stacks teams actually use.

• React (i18next component patterns), Next.js (App Router i18n middleware & routing)
• Vue 3 (Composition API), Angular (@angular/localize), SvelteKit, Astro
• Type-safe hooks, middleware routing, SSR hydration, and locale cookie persistence
• Tooling decisions like FormatJS vs Lingui, compared end to end

Automation that keeps translations flowing without breaking builds.

• Crowdin and Weblate integrations for dev teams (including self-hosted)
• AST-based key extraction with i18next-parser
• GitHub Actions CI gates that fail the build on untranslated keys
• PO ↔ XLIFF format bridging without data loss
• Machine-translation pre-fill workflows with quality gates

Full-stack developers, UX engineers, product teams, and localization managers who need internationalization that is deterministic, cache-aware, edge-ready, and scales past the first few locales.

• ✍️ 51 in-depth technical guides across three coherent areas, tightly cross-linked.
• 🎨 Hand-authored inline SVG diagrams — architecture, sequence, and comparison visuals that adapt to light/dark themes; no stock imagery.
• ❓ FAQ accordions and runnable code examples on every page.
• 🔎 SEO-ready structured data (JSON-LD TechArticle + breadcrumbs), sitemap, and canonical URLs.
• 📱 Installable PWA — web app manifest, service worker, and generated icons.
• ⚡ Fast by construction — a static Eleventy build served at the edge as a Cloudflare Worker.

Zero runtime dependencies — the shipped site is plain HTML, CSS, and a little JavaScript.

npm install          # install build tooling
npm start            # generate icons + serve with live reload at http://localhost:8080
npm run build        # produce the static site in ./_site

content/        Markdown guides + Nunjucks pages (index, sitemap, robots), organized by area
_includes/      Nunjucks layouts (base, home, content)
_data/          Global site data (site.json) and asset cache-busting hashes
assets/         CSS, JS, icons, service worker, manifest
scripts/        Build helpers (icon generation)
src/            Cloudflare Worker entry
wrangler.toml   Cloudflare Workers configuration

The site builds to static files and deploys as a Cloudflare Worker serving those assets:

npm run deploy       # npm run build && wrangler deploy

Routes are served on both i18n-l10n.com/* and www.i18n-l10n.com/* (canonical is www).

Built and maintained as an open technical reference for the internationalization community. Spot something wrong or missing? Open an issue.