Home Domain Search AI Generator Premium Domains DNS Health SSL Checker Compare Blog FAQ

Domain, Website Security, and Search Visibility Guides

Evidence-led guides on naming, public website security signals, and search and AI visibility for builders and development teams.

Read how the Search and AI Visibility check works, including sources and limitations.

Articles are published and reviewed by DomainOptic. Quantified original research includes its sample and limitations, and factual third-party claims should link to their source. Send corrections to brenbuilds@protonmail.com.

Subscribe via RSS

Start Here

Original data
197 discovered, 100 indexed

A dated Search Console case study showing why sitemap discovery and indexing are different measurements.
Domain research
How to check domain availability

A practical path from point-in-time lookup to registrar confirmation.
Public code
What NEXT_PUBLIC_ really exposes

How client-visible environment variables work and which findings require action.

All Articles

Guide
We Checked 80 Popular SaaS Tools for AI Crawler Access. 70 Block Nothing.

Published August 17, 2026 · By DomainOptic · 7 min read

First-party measurement of robots.txt policy across 80 well-known developer and SaaS tools: 91 percent of readable files block no documented AI crawler at all. Full method and domain list included.
Guide
137 Pages Crawled but Not Indexed: The Cut We Finally Made

Published August 17, 2026 · By DomainOptic · 6 min read

The sequel to our July indexing case study: the numbers got worse, the glossary measured at zero impressions across 121 pages, and we removed it from the index race. Real Search Console data throughout.
Guide
197 URLs Discovered, 100 Indexed: A July 2026 Search Console Case Study

Published July 23, 2026 · By DomainOptic · 6 min read

First-party Search Console data from DomainOptic shows why sitemap discovery is not the same as indexing, plus the content and measurement changes made next.
Guide
Hacker News Website Security Snapshots: 85 Passive Scans

Published February 19, 2026 · Updated July 18, 2026 · By DomainOptic · 7 min read

What two passive scans of 50 and 35 Hacker News sites found about security headers, DNS email authentication, exposed-secret patterns, and TLS.
Guide
Prompt Injection Defense Checklist for AI Apps (2026)

Published February 8, 2026 · Updated February 19, 2026 · By DomainOptic · 9 min read

Practical prompt injection defense checklist for AI apps in 2026: system prompt hardening, tool-call guardrails, output validation, and retrieval isolation.
Guide
AI Agent Security Audit Checklist: 12 Checks Before Production (2026)

Published February 7, 2026 · Updated February 19, 2026 · By DomainOptic · 10 min read

A production-ready AI agent security audit checklist for 2026 covering identity, permission boundaries, tool controls, logging, and rollback safety.
Guide
RAG Security in 2026: Stop Prompt Injection and Data Exfiltration

Published February 6, 2026 · Updated February 19, 2026 · By DomainOptic · 11 min read

How to secure RAG pipelines against prompt injection and data exfiltration in 2026 with retrieval isolation, policy filters, and response controls.
Guide
Secure LLM API Key Management: What Must Stay Server-Side (2026)

Published February 5, 2026 · Updated February 19, 2026 · By DomainOptic · 8 min read

A 2026 guide to secure LLM API key management: what can be public, what must remain server-side, rotation strategy, and blast-radius reduction.
Guide
AI Startup Security Checklist (2026): From DNS to Prompt Injection

Published February 4, 2026 · Updated February 19, 2026 · By DomainOptic · 12 min read

Launch checklist for AI startups in 2026 covering web security baseline, secret scanning, DNS email auth, prompt injection controls, and monitoring.
Guide
Is This Website Safe? 5 Ways to Check Any Site Before You Click

Published December 21, 2025 · Updated July 18, 2026 · By DomainOptic · 8 min read

Learn how to check if a website is safe before entering personal information. Five quick methods: HTTPS check, domain verification, security scan, red flags, and reputation research.
Guide
How to Fix 'Your Connection Is Not Private' Error

Published December 21, 2025 · By DomainOptic · 9 min read

Step-by-step guide to fix 'Your connection is not private' error in Chrome, Firefox, Edge, Safari. Solutions for visitors and website owners.
Guide
What Is HSTS? HTTP Strict Transport Security Explained

Published December 21, 2025 · By DomainOptic · 7 min read

HSTS forces browsers to use HTTPS, preventing downgrade attacks. Learn how it works, how to implement it in nginx/Apache, and common mistakes to avoid.
Guide
SPF Record Explained: What It Is and How to Set It Up

Published December 21, 2025 · Updated July 18, 2026 · By DomainOptic · 10 min read

Complete guide to SPF records for email authentication. Learn the syntax, see real examples, and avoid the mistakes that cause emails to go to spam.
Guide
Why Are My Emails Going to Spam? Complete Troubleshooting Guide

Published December 21, 2025 · Updated July 19, 2026 · By DomainOptic · 11 min read

Your emails landing in spam? Check your SPF, DKIM, and DMARC records, verify sender reputation, and review email content. This guide covers all the causes and fixes.
Guide
Website Security Checklist: 10 Things to Check Before Launch

Published December 20, 2025 · Updated July 18, 2026 · By DomainOptic · 8 min read

Launch your website with confidence. This 10-point security checklist covers SSL, headers, DNS, secrets, and common vulnerabilities every site should address before going live.
Guide
Website Security Scanner Tools Compared

Published December 16, 2025 · Updated July 19, 2026 · By DomainOptic · 10 min read

Compare the public checks offered by DomainOptic, SecurityHeaders.com, Mozilla Observatory, and Qualys SSL Labs across SSL, DNS, headers, and exposed-secret patterns.
Guide
Vibe Coder Security Checklist: Reviewing AI-Generated Code

Published December 16, 2025 · Updated July 18, 2026 · By DomainOptic · 9 min read

Security checklist for vibe coders using AI to write code. Prevent API key leaks, SQL injection, and XSS in Claude, Cursor, and Copilot-generated code. Ship fast, stay secure.
Guide
Website Security Audit: A Beginner's Guide

Published December 16, 2025 · Updated July 18, 2026 · By DomainOptic · 12 min read

Learn how to run a website security audit step by step. Check SSL certificates, DNS health, security headers, and exposed secrets. No security experience required.
Guide
Exposed API Keys in JavaScript: How Hackers Find Your Secrets

Published December 9, 2025 · By DomainOptic · 8 min read

Learn how attackers scan public JavaScript bundles for exposed API keys, AWS credentials, and secrets. Audit your site with DomainOptic's Secret Scanner.
Guide
Website Security Audit Checklist: SSL, DNS, Headers, and Secrets

Published December 8, 2025 · Updated July 18, 2026 · By DomainOptic · 7 min read

Run a directional passive website audit: review SSL, selected DNS records, security headers, reputation responses, and potential secret patterns in public JavaScript.
Guide
SSL Certificate Audit Guide: Expiry, SAN, Protocols, and Redirects

Published December 8, 2025 · Updated July 18, 2026 · By DomainOptic · 6 min read

Audit TLS expiry, hostname coverage, protocol strength, revocation guidance, certificate chains, and HTTPS redirects in a few steps.
Guide
DNS Security Audit Checklist: SPF, DKIM, DMARC, DNSSEC, and CAA

Published December 8, 2025 · Updated July 18, 2026 · By DomainOptic · 7 min read

Audit DNS for security and deliverability: SPF, DKIM, DMARC, DNSSEC, MX, and CAA so spoofing and inbox issues stay away.
Guide
Domain Monitoring: Current Setup and Alert Scope

Published December 5, 2025 · Updated July 18, 2026 · By DomainOptic · 6 min read

Monitor up to two domains for selected high-confidence security changes. DomainOptic monitoring requires sign-in and no card to start.
Guide
Website Security Headers Explained: A Practical Guide

Published December 1, 2025 · Updated July 18, 2026 · By DomainOptic · 9 min read

Learn about HTTP security headers, why they matter, and how to implement them to protect your website from common attacks.
Guide
SSL/TLS Certificate Security: Everything You Need to Know

Published November 30, 2025 · Updated July 21, 2026 · By DomainOptic · 10 min read

SSL/TLS certificates explained: types, validation levels, the shrinking validity schedule through 2029, and how to check certificate health.
Guide
DNS Security Best Practices: Protecting Your Domain

Published November 29, 2025 · Updated July 18, 2026 · By DomainOptic · 8 min read

Learn how to secure your DNS configuration to prevent hijacking, spoofing, and other DNS-based attacks on your domain.
Guide
How to Check Domain Availability: 2026 Guide

Published November 28, 2025 · Updated July 23, 2026 · By DomainOptic · 8 min read

Check domain availability with current RDAP data, understand fallback signals, and know why the registrar remains the final authority.
Guide
Domain Name Generators Compared: What to Check

Published November 27, 2025 · Updated July 18, 2026 · By DomainOptic · 10 min read

Compare the top domain name generators including AI-powered tools. Find the best free domain generator for your business or startup.
Guide
WHOIS and RDAP: Domain Registration Lookup Guide

Published November 26, 2025 · Updated July 18, 2026 · By DomainOptic · 7 min read

Learn how RDAP replaced contractual WHOIS services for generic domains in 2025, what registration data contains, and where legacy WHOIS remains.
Guide
Premium Domain Names: Are They Worth the Investment?

Published November 25, 2025 · Updated July 18, 2026 · By DomainOptic · 9 min read

Should you buy a premium domain? Learn what makes a name premium, how to set a budget, and how to verify a purchase safely.
Guide
Domain Name vs URL vs Website: What's the Difference?

Published November 24, 2025 · By DomainOptic · 6 min read

Confused about domain names, URLs, and websites? Learn the clear differences between these commonly confused terms.
Guide
How to Choose a Domain Name for Your Business: 15 Practical Tips

Published November 23, 2025 · Updated July 18, 2026 · By DomainOptic · 11 min read

Practical tests for choosing a business domain: spelling, extension, trademark risk, renewal terms, portability, and audience recognition.
Guide
.com vs .io vs .ai: Which Domain Extension Should You Choose?

Published November 22, 2025 · Updated July 18, 2026 · By DomainOptic · 8 min read

Detailed comparison of .com, .io, and .ai domain extensions. Learn which TLD is best for your startup or tech business.
Guide
What Happens When a Domain Name Expires? Complete Guide

Published November 21, 2025 · Updated July 18, 2026 · By DomainOptic · 7 min read

Learn what happens when a domain expires, the grace period process, and how to get an expired domain before others do.
Guide
Free vs Paid Domain Names: What You Need to Know

Published November 20, 2025 · Updated July 18, 2026 · By DomainOptic · 6 min read

Compare a hosted subdomain with a domain you register, including control, portability, email, renewal costs, and the cases where either choice makes sense.
Guide
How to Transfer a Domain Name to a New Registrar

Published November 19, 2025 · Updated July 18, 2026 · By DomainOptic · 8 min read

A current guide to registrar transfers, including transfer locks, authorization codes, DNS continuity, timing, and ICANN policy limits.
Guide
AI Domain Name Generation in 2026: Benefits and Limits

Published January 5, 2026 · Updated July 19, 2026 · By DomainOptic · 6 min read

How AI helps with domain brainstorming, what availability checks can establish, and which brand, trademark, and pricing decisions still require human review.
Guide
How to Find Available .com Domains for Your Startup

Published May 22, 2025 · Updated July 18, 2026 · By DomainOptic · 7 min read

Practical tactics to secure a great .com domain for your startup.
Guide
Why Every Domain Needs HTTPS

Published April 6, 2025 · Updated July 18, 2026 · By DomainOptic · 8 min read

HTTPS is essential for security, trust, and SEO. Learn why your website needs it.
Guide
Understanding Domain Authority

Published January 4, 2026 · Updated July 19, 2026 · By DomainOptic · 9 min read

What is Domain Authority and why does it matter for SEO?
Guide
Choosing the Right Domain Extension (TLD)

Published January 3, 2026 · Updated July 19, 2026 · By DomainOptic · 10 min read

.COM, .ORG, .AI? Choosing Your Top-Level Domain (TLD)
Guide
Tips for Picking a Memorable Domain Name

Published January 2, 2026 · Updated July 19, 2026 · By DomainOptic · 10 min read

Your domain name is your digital address. Learn how to make it memorable.
Guide
Understanding Domain Privacy Protection

Published April 3, 2025 · Updated July 18, 2026 · By DomainOptic · 5 min read

What is domain privacy and why do you need it?
Guide
Why Your NEXT_PUBLIC_ Variables Might Be Exposing Secrets

Published December 28, 2025 · Updated July 18, 2026 · By DomainOptic · 7 min read

Environment variables prefixed with NEXT_PUBLIC_ are bundled into your client-side JavaScript. If you're storing API keys there, they're visible to everyone. Here's how to check and fix it.
Guide
Source Maps in Production: Your Code's Hidden Tell-All

Published December 28, 2025 · Updated July 18, 2026 · By DomainOptic · 6 min read

Source maps make debugging easier, but in production they expose your original source code, comments, and API endpoints. Here's how to check if yours are exposed and how to fix it.
Guide
Security Headers in vercel.json and netlify.toml

Published December 28, 2025 · Updated July 18, 2026 · By DomainOptic · 8 min read

A safe starting point for response headers on Vercel and Netlify, with current CSP, HSTS, and obsolete-header guidance.

Browse by Topic

AI Security (Primary) - Prompt Injection Defense, AI Agent Security Audit, RAG Exfiltration Defense, LLM API Key Management, AI Startup Security Checklist
Website Security (Primary) - Website Security Audit Guide, Scan Exposed API Keys, NEXT_PUBLIC_ Secret Risks, Source Map Risks, Security Headers Configs, DNS Security, SSL/TLS Security
Domain Strategy (Secondary) - Checking Availability, Domain Naming, TLD Comparison, Premium Domains, WHOIS Guide

About This Blog

DomainOptic Blog helps builders understand domain strategy and public website security. Learn prompt injection defense, AI agent security audits, RAG exfiltration prevention, website security audits, exposed API key detection, SSL hardening, DNS authentication, and security headers.

← Back to Domain Search