How It Works

Architecture

0io.io runs entirely on Cloudflare Workers — a serverless edge runtime that executes code in 300+ data centers worldwide. There are no origin servers, no databases, and no cold starts.

User clicks link
       │
       ▼
┌──────────────┐
│  Cloudflare  │  Nearest edge PoP
│   Worker     │  (< 50ms globally)
└──────┬───────┘
       │
       ▼
┌──────────────┐
│  Redirect    │  HTML page with:
│  Page        │  • Auto-redirect via JS
│              │  • Manual fallback button
│              │  • OG / Twitter meta tags
│              │  • JSON-LD structured data
└──────────────┘
       │
       ▼
  Native app opens
  (mail client, phone
   dialer, VS Code, etc.)

URL Format

The format is simple — append the full URI after the domain:

https://0io.io/{scheme}:{target}

The worker extracts everything after the / as the target URI and generates a redirect page.

With Description

You can add a ?d= query parameter to customize the description shown on the redirect page:

https://0io.io/mailto:hello@example.com?d=Contact+our+support+team

Redirect Flow

1. Request arrives at the Cloudflare Worker edge
2. Scheme is parsed from the URI path
3. Security check — dangerous schemes (javascript:, data:, vbscript:) are flagged
4. HTML page is generated with:
   • Auto-redirect via window.location.replace() (safe schemes only)
   • A manual "Click here if not redirected" button
   • Open Graph and Twitter Card meta tags for rich previews
   • JSON-LD structured data for search engines
   • Optional Google Analytics / GTM tracking
5. Page is served from the nearest edge location

SEO Features

Each redirect page includes:

• Open Graph tags — rich previews when shared on social media
• Twitter Cards — optimized for Twitter/X sharing
• JSON-LD — structured data (WebPage + ViewAction) for search engines
• Canonical URLs — proper rel=canonical for each unique URI
• Descriptive titles — scheme-aware titles like "Send email to hello@example.com"

Performance

• No cold starts — Cloudflare Workers are always warm
• Global edge — served from the closest data center to the user
• Tiny payload — the redirect page is a single self-contained HTML document (no external JS/CSS bundles)
• Instant redirect — window.location.replace() fires immediately on page load