About IsThisValid.com

IsThisValid.com is a free verification hub. Whether you've received a suspicious text, want to check a sketchy link before clicking it, or need to validate an email address, we have a tool for it — no account, no sign-up, no personal data stored.

All four tools are accessible directly in your browser; submitted data is processed server-side and never permanently stored.

1. Phone Number Checker — validates any phone number against ITU-T rules using libphonenumber-js, identifies the country, line type (mobile, landline, VoIP, toll-free, etc.), and (optionally) enriches results with live carrier and line-status data via the AbstractAPI. Try it →
2. Text / SMS Scam Detector — paste any suspicious message and our AI (powered by Anthropic Claude) analyses it for scam, smishing, spam, and social-engineering patterns. It flags specific phrases and explains its reasoning. Try it →
3. Email Validator — checks whether an email address passes RFC 5322 syntax rules, belongs to a known disposable-email provider (57,000+ domains), has valid DNS MX records, and (optionally) whether the mailbox actually exists. Results are scored 0–100. Try it →
4. URL Safety Checker — checks URLs for phishing signals, suspicious keywords, brand-squatting, punycode tricks, IP addresses masquerading as domains, URL shorteners, and known malware/phishing lists via the Google Safe Browsing API. Try it →

Scams are getting harder to spot. Smishing texts impersonate banks and couriers convincingly. Phishing URLs differ from the real thing by a single character. Disposable email addresses pollute sign-up flows. None of these problems require expensive software to catch — they just need a quick, reliable check.

IsThisValid.com is deliberately simple. No logins, no dashboards, no plans to upsell you into a SaaS tier. Just paste, check, done.

Phone Number Checker — validation runs locally first using libphonenumber-js (no network calls). If an AbstractAPI key is configured, we enrich the result with live carrier name, line type, ported status, and line-active confirmation. Phone numbers are never stored — only their SHA-256 hash is cached for up to 30 days as a cache key.

Text / SMS Scam Detector — your message is sent to our server and forwarded to Anthropic's Claude API with a strict system prompt that instructs the model to classify the message and extract specific red flags. The output is validated against a schema before being returned to you. Results are cached for 24 hours (by a one-way hash of the message) to avoid redundant AI calls for the same viral scam text.

Email Validator — validation runs in two layers: local checks (syntax, TLD, disposable domain list, MX DNS) happen in milliseconds with no third-party calls. If a ZeroBounce or Emailable API key is configured, we also perform an SMTP-level handshake to verify mailbox reachability.

URL Safety Checker — nine local heuristics run first (no network calls, instant). If the URL passes, we make a HEAD request to check reachability, then query the Google Safe Browsing API against its threat database.

None of the content you submit — email addresses, URLs, text messages, or phone numbers — is permanently stored on our servers. Text messages submitted to the scam detector are forwarded to Anthropic for analysis; a one-way cryptographic hash may be cached briefly to avoid duplicate calls. For full details, see our Privacy Policy.

IsThisValid.com is completely free to use — no account, no limits, no catch. Running AI analysis and third-party API calls costs real money, so if you find the tools useful, a ☕ via Ko-fi goes a long way. We may also display contextual advertisements in the future to help cover costs. Advertising never affects our results — we have no commercial relationship with any service we check against, and no financial incentive to report a result as safe or unsafe.

IsThisValid.com was designed and built by Mike Sywensky, a full-stack developer and engineering manager with over 10 years of experience in Pharma and over six in Finance. If you're looking for a contractor for your next project, feel free to reach out.

Questions, feedback, or bug reports about the tools? Reach us at [email protected].