underscoredone.com

Look up the network operator, country, and address block behind any IP address or ASN number.

Checks whether a website's email branding setup is correct so its logo shows up in inboxes.

Send a URL and origin, get back exactly which cross-origin permissions that server grants.

Returns the latest, a specific month's, or a historical range of official US inflation (CPI) figures from BLS .

Make a real HTTP request from the cloud and get back the status code, headers, and body instantly.

Places an order to have a website submitted to twenty directories, returning a confirmation number to track it.

Check email security (DMARC) configuration for one or many domains in a single request.

Look up all 13 DNS record types plus full WHOIS registration data for up to 10 domains in one call.

Give it a list of domains and get back registration date, expiration date, age, and time remaining — instantly.

Check whether 1–10 domain names have an active registration record using the official RDAP protocol.

Checks if a single email address is real, risky, or dead before you send to it.

Resolve an ENS name to an Ethereum address, or an address back to its ENS name.

Fetch Hacker News stories by category, or scan all stories/jobs/polls from a specific date, with optional nested comments.

Compute cryptographic hashes, HMAC signatures, and checksums — and verify webhook signatures with constant-time comparison.

Fetches any web address and returns its response headers, status code, and redirect path.

Check the live status of up to 10 URLs at once and detect redirects instantly.

One endpoint to validate, repair, format, query, diff, convert, and canonicalize JSON - the most common operation in every agent workflow.

Converts regular text into leetspeak or decodes leetspeak back into normal readable text.

Get the exact monthly payment and full period-by-period breakdown for any fixed-rate loan - results an AI model cannot reliably compute on its own.

Extract text from any image using Tesseract OCR.

Send a host and port range, get back a clean list of which ports are open and what services are running on them.

Turn a list of text, URLs, or any strings into QR code images instantly — one call, many codes.

Capture a screenshot of a fully rendered webpage, including JavaScript-heavy pages.

Fetch a webpage and instantly extract all key SEO fields: title, meta tags, headings, canonical URL, and more.

Check exactly where your Shopify product ranks when AI shopping assistants like ChatGPT and Gemini search for it.

Give it a sitemap.xml link and get back every URL listed in it — including nested sub-sitemaps — with metadata like last modified date and change frequency.

Checks whether a website or web address is currently reachable and reports how fast it responded.