Domain & SSL Inspector
Analyze domain name architecture, multi-part TLD classifications, Shannon entropy randomness, homograph attack risks, and RDAP registration endpoints.
Domain Architecture & Security Matrix
Domain Architecture Analysis and Security Inspection
The Domain and SSL Inspector provides in-depth technical analysis of fully qualified domain names (FQDNs), evaluating structural taxonomy, top-level domain classifications, algorithmic randomness, and internationalized homograph attack risks. Designed for cybersecurity analysts, web developers, and domain researchers, the tool deconstructs complex hostnames into distinct architectural layers.
Domain names must adhere to strict internet standards defined in RFC 1035 and the Mozilla Public Suffix List (PSL). This inspector determines the exact boundary between the effective top-level domain (eTLD) and the registered second-level domain (SLD), correctly parsing multi-part extensions like co.uk or com.au. It also computes the mathematical Shannon entropy of the domain string (measured in bits per character) to identify potential Domain Generation Algorithm (DGA) malware signatures.
The security inspector evaluates Unicode Internationalized Domain Names (IDN) for homograph spoofing vulnerabilities. By identifying mixed-script characters where Cyrillic, Greek, or Latin glyphs look identical, the tool alerts users to deceptive phishing domains. Direct links to ICANN Registration Data Access Protocol (RDAP) services allow users to check official registrar records without third-party tracking.
Core Tool Capabilities
- Public Suffix List Architecture Breakdown: Accurately separates hostnames into subdomains, root domains, SLDs, and eTLD suffixes using official PSL rules.
- Shannon Entropy Algorithmic Analysis: Computes character randomness metrics to detect machine-generated domains, DGA patterns, and suspicious hostnames.
- Unicode IDN Homograph Risk Detection: Identifies lookalike characters across mixed linguistic scripts that mimic legitimate brand domains for phishing attacks.
- RFC 1035 Domain Protocol Validation: Verifies label lengths, total FQDN byte ceilings (253 octets), and valid character sets against RFC standards.
- Top-Level Domain Classification: Identifies TLD categories including generic (gTLD), country-code (ccTLD), sponsored (sTLD), and infrastructure extensions.
- One-Click RDAP Registration Lookup: Generates verified links to authoritative ICANN RDAP endpoints for official registrar and ownership verification.
Local Browser Privacy
Your files are processed locally on your device. Files are not uploaded, transmitted, or stored on remote servers.
Once the page has loaded, you can disconnect your network connection and continue using this tool offline.
Target Use Cases
- • Cybersecurity Phishing Detection
- • Malware Threat Intelligence
- • Domain Portfolio Management
- • Web Application Architecture
Technical Specifications & Platform Limits
Conforms to internet domain naming and public suffix boundary rules.
Mathematical randomness index evaluating algorithmic domain generation.
Identifies mixed Latin, Cyrillic, and Greek character substitutions.
RFC-compliant structural byte length verification.
All parsing and entropy calculations execute locally in client memory.
Step-by-Step Workflow
Enter Domain Name
Paste or type a domain name, hostname, or full URL into the domain analysis input field. The parser cleans and normalizes the input.
Review Architectural Breakdown
Examine the deconstructed hierarchy showing subdomains, registered root domain, and verified TLD classification. Confirm boundary accuracy.
Analyze Security Metrics
Inspect the calculated Shannon entropy score and the Unicode IDN homograph threat assessment card. Look for high randomness or script mixing.
Export Inspection Summary
Click the copy report button to copy the complete architectural and security summary to your clipboard for audit documentation or tickets.
Practical Real-World Use Cases
Cybersecurity Phishing Detection
Security analysts evaluating suspicious email links to detect Unicode homograph lookalike domains used in credential harvesting campaigns.
Malware Threat Intelligence
Incident response teams measuring Shannon entropy to identify algorithmic domains generated by botnets and command-and-control malware.
Domain Portfolio Management
Brand protection specialists and domain investors auditing portfolio naming conventions, TLD categories, and registrar records.
Web Application Architecture
Developers verifying cookie domain scopes and subdomain routing boundaries against the Mozilla Public Suffix List.
Frequently Asked Questions
- What is the Public Suffix List and why is it important for domain parsing?
- The Public Suffix List (PSL) is an authoritative catalog of domain suffixes under which internet users can directly register names. It includes traditional top-level domains like .com, country codes like .de, and multi-part public registries like .co.uk or .github.io. Without the PSL, software cannot reliably determine where the public suffix ends and the private registered domain begins, which is critical for setting secure browser cookies.
- What is Shannon entropy in domain analysis?
- Shannon entropy measures the amount of unpredictability or randomness in a string of characters, expressed in bits per character. Legitimate domain names chosen by humans typically have lower entropy because they use dictionary words and pronounceable syllables. In contrast, machine-generated domains used by malware (such as Domain Generation Algorithms) exhibit high entropy scores, signaling suspicious random text.
- How does a Unicode IDN homograph attack work?
- An Internationalized Domain Name (IDN) homograph attack occurs when an attacker registers a domain using characters from non-Latin scripts (such as Cyrillic or Greek) that look identical to standard Latin letters. For example, the Cyrillic letter 'а' (U+0430) looks identical to the Latin letter 'a' (U+0061). To human eyes, the web address appears legitimate, but it points to an entirely different malicious server.
- What are the maximum length limits for internet domains under RFC 1035?
- RFC 1035 specifies that each individual domain label (the text between dots) cannot exceed 63 octets (characters), and the total length of a fully qualified domain name (FQDN) cannot exceed 253 octets. The inspector automatically validates your input against these technical ceilings to ensure compliance.
- Are the domains I inspect recorded in any database?
- No. All domain deconstruction, entropy calculation, homograph scanning, and RFC validation run entirely in your local browser runtime using client-side JavaScript. No domains, hostnames, or search queries are transmitted to or stored on our servers.
Share this tool
Help others discover this utility. No login or registration required.
Master this tool with Guides & Articles
Learn the workflows, common mistakes, and advanced techniques behind Domain & SSL Inspector - Structure, Entropy, Homograph & RDAP Audit with our deep-dive educational content.
How to Check File Size Before Uploading Files Online
Learn how to check file size before uploading files to email platforms, CMS systems, cloud storage, APIs, and messaging apps. Explore browser-native payload analysis, upload compatibility checks, transfer estimates, and file optimization workflows with SHRTX.
Deep Linking Guide: Connecting Web, Mobile, and Desktop Routes
Learn how deep links, Universal Links, Android App Links, fallback URLs, QR flows, and deferred routing connect app paths.
Designing Glitch Art with Browser-Native Image Workflows
Learn databending, JPEG and PNG corruption behavior, pixel-sorting pipelines, and browser-local rendering workflows for glitch art.