Focused, browser-first developer utilities for technical SEO auditing, GEO answer readiness, Caddyfile transpilation, Apple Wallet PKPass inspection, visual CIDR subnet calculations, and email security verification - fast, transparent, and completely free.
Check whether a page is accessible, structured, attributable, and easy for answer engines to understand and cite.
Open tool → 02Find redirect mistakes, crawler traps, duplicate URL spaces, canonical problems, and sitemap gaps.
Open tool → 03Generate dark-mode adaptive vector favicons, multi-resolution ICOs, Apple touch icons, and Android PWA bundles with safe-zone masking.
Open tool → 04Diagnose cross-origin headers, preflight OPTIONS requests, wildcard credentials safety, and browser max-age limits.
Open tool →Prepare strict SVG Tiny 1.2 PS brand marks with safe-zone padding and live inbox simulator for Gmail, Apple Mail, and Yahoo.
Open tool → 061-click verification of DMARC policies, BIMI records, MTA-STS strict transport security, SMTP TLS-RPT, and SPF.
Open tool →Convert Nginx server blocks and Apache .htaccess into clean, idiomatic Caddyfiles with real-time smart mapping, migration advisories and 1-click presets.
Open tool → 08Analyze IPv4/IPv6 CIDR blocks, detect IP range overlap collisions, view 2D spatial tree partitions, and find available free subnets.
Open tool → 09Transpile regular expressions between PCRE, JavaScript, Python, Go, and Rust dialects with automated feature and edge-case warnings.
Open tool → 10Trace authoritative DNS delegation from root (.) to TLD and name servers, detect lame delegations and visualize resolution DAGs.
Open tool →Pixel-perfect Apple Wallet & Google Wallet emulator, SHA-1 manifest validator, PKCS#7 certificate inspector, and 1-click package repair.
Open tool → 12Validate Apple AASA and Android AssetLinks manifests, test URL routing patterns, and diagnose deeplink failures.
Open tool →Calculations stay in your browser. Crawled reports are cached to avoid repeatedly hitting a site.
Formulas, evidence, dates, and limitations appear next to the result instead of hiding behind a score.
Each tool is designed around one concrete task, with no paywalls, signups, or artificial delays.
StackHal provides instant developer utilities including technical SEO crawling audits, GEO (Generative Engine Optimization) readiness checks, Nginx/Apache to Caddyfile transpilation, Apple Wallet PKPass inspection, visual CIDR subnet analysis, BIMI and domain security verification, and CORS debugging.
Yes, all tools run without registration or signups. Client-side utilities process files and configurations directly inside your browser for total privacy.
The GEO Analyzer inspects real technical and content signals-such as JSON-LD structured data, concise opening answers, semantic landmarks, author attribution, citation trails, and AI crawler permissions in robots.txt. Standard specifications: Schema.org ↗ and MDN Web Docs ↗.
Use our online Caddy Transpiler to paste your existing configuration and immediately receive an idiomatic Caddyfile with automated routing advice and security optimizations. Documentation references: Caddy Server Docs ↗ and Apple PassKit Specs ↗.