GUIDES
Guides
Reference pages about screening emails, links, domains, payments and AI input. Each one lists its sources and the date it was last updated.
Email and signups
ComparisonDisposable email detection APIs compared (2026)Which disposable email API should you use? Eight options compared on price per 1,000 lookups, approach and list size. Prices checked October 2026.Updated 2026-10-10ReferenceEmail validation vs email verification: what each one does to your usersValidation checks an address without contacting the mailbox, SMTP verification probes it, and only a confirmation email proves ownership.Updated 2026-10-10Original dataHow disposable email services hide, and how shared mail servers give them awayDisposable email domains change constantly, but the mail servers behind them do not. Measured results from a 61,888-domain list.Updated 2026-10-10Original dataHow old are disposable email domains?RDAP registration dates for 335 live disposable email domains: median age 5.3 years, only 2.1% under 30 days old.Updated 2026-10-10Original dataWhich mail servers disposable email domains run onWe resolved MX for 2,000 random disposable domains: 69% have no mail server, and the rest cluster on a few dozen hosts.Updated 2026-10-10
Links and domains
FREE TOOLSRedirect checker
Payments and PII
FREE TOOLSIBAN checker
AI and prompt security
No free tool for this topic yet
ComparisonPerspective API is shutting down: alternatives for toxicity and comment moderationPerspective API ends 31 December 2026. Compare OpenAI, Azure, Google, AWS, Hive, Sightengine, Detoxify and Llama Guard on attributes and self-hosting.Updated 2026-10-10ComparisonPrompt injection detection tools compared (2026)Which prompt injection detector fits your stack? Lakera, Prompt Guard 2, LLM Guard, Bedrock, Azure, Model Armor and more, with sourced prices.Updated 2026-10-10
Comparisons
StormDoor makes one of the tools in each comparison, and every comparison says so.
ComparisonDisposable email detection APIs compared (2026)Which disposable email API should you use? Eight options compared on price per 1,000 lookups, approach and list size. Prices checked October 2026.Updated 2026-10-10ComparisonPerspective API is shutting down: alternatives for toxicity and comment moderationPerspective API ends 31 December 2026. Compare OpenAI, Azure, Google, AWS, Hive, Sightengine, Detoxify and Llama Guard on attributes and self-hosting.Updated 2026-10-10ComparisonPrompt injection detection tools compared (2026)Which prompt injection detector fits your stack? Lakera, Prompt Guard 2, LLM Guard, Bedrock, Azure, Model Armor and more, with sourced prices.Updated 2026-10-10