Web Diagnostics Developer Tools
Debug crawl signals, URLs, headers, DNS, email authentication, and public web behavior from one focused collection.
JWT Decoder
Decode JSON Web Tokens — inspect header, payload, and signature without a secret.
Open toolURL Parser, Encoder & UTM Query Builder
Parse URLs into clean components, decode query strings, edit parameters live, and build UTM-tagged campaign links safely in your browser.
Open toolCron Parser, Builder & Timezone Translator
Parse cron expressions, build schedules visually, preview the next run times, and compare server UTC with your local timezone.
Open toolAWS EventBridge Cron & Rate Expression Builder
Build valid AWS EventBridge Scheduler expressions, avoid day-field conflicts, preview the next runs, and compare UTC with your local timezone.
Open toolSecure HAR Viewer, Analyzer & Secret Sanitizer
Inspect HAR files locally, rank slow requests, compare traces, and redact cookies, tokens, API keys, and other secrets before sharing.
Open toolHTTP Headers Checker
Fetch and inspect the HTTP response headers of any public URL in a clean, readable view.
Open toolDNS Record Lookup & Propagation Checker
Inspect A, AAAA, CNAME, MX, TXT, NS, and CAA answers with conflict guidance and resolver comparison.
Open toolMeta Tag & SERP Previewer
Draft SEO titles, meta descriptions, Open Graph tags, and social cards locally, with practical SERP and sharing previews before you publish.
Open toolSchema.org JSON-LD Generator & Validator
Build, validate, and export structured data for Article, Product, Local Business, Event, Job Posting, and more — locally in your browser.
Open toolSlug Generator & URL Sanitizer
Convert messy titles into clean, SEO-friendly URL slugs, normalize accents, remove symbols, and generate bulk slugs locally in your browser.
Open toolCanonical URL Builder & Checker
Normalize messy URLs, strip tracking parameters, and generate clean rel="canonical" tags locally in your browser.
Open toolURL Indexability Inspector
Inspect live status codes, redirect chains, robots directives, canonical tags, and hreflang signals to understand whether a URL is likely indexable.
Open toolHreflang Cluster Validator
Validate reciprocal hreflang clusters, check ISO language-region codes, verify x-default fallback, and detect canonical-hreflang conflicts across multilingual and multi-regional pages.
Open toolStructured Data Validator & Rich Result Gap Checker
Validate JSON-LD, extract structured data from live pages, and find missing fields that may block Google rich result eligibility.
Open toolOpen Graph & Social Preview Inspector
Fetch any live URL, inspect Open Graph and Twitter/X tags, simulate social previews for Facebook, LinkedIn, Slack, and iMessage, and validate og:image dimensions before you share.
Open toolRobots.txt Checker
Validate robots.txt syntax, test crawl rules by bot, and catch blocking mistakes that can hurt indexing.
Open toolAI Crawler Rules Builder & robots.txt Generator
Generate SEO-safe robots.txt rules for AI crawlers, search bots, and archive bots. Block training bots without accidentally blocking search visibility.
Open toolSitemap Checker
Validate XML sitemaps, inspect listed URLs, and uncover technical issues that reduce crawl and index efficiency.
Open toolllms.txt Generator & Checker
Create and audit an experimental llms.txt file that gives AI tools a cleaner Markdown map of your site, docs, and core context.
Open toolVisual Subnet Calculator & CIDR Range Validator
Plan IPv4 and IPv6 networks visually, split subnets, check overlaps, and compare usable IPs across AWS, Azure, and Google Cloud.
Open toolDocker Compose Validator & Service Graph
Validate Compose files for port collisions, risky dependency patterns, missing env vars, and outdated syntax. Instantly generate a visual service graph.
Open tool