218 services carry this tag in their source record. Tags come from the provider, not from us — a tag is a claim about what the service does, not proof that it does it well.
Check an ISBN-10 or ISBN-13 check digit and convert valid ISBN-10s to ISBN-13. Hyphens and spaces are ignored. Use before cataloguing or ordering books.
Base58 encode or decode bytes/hex (Solana-style base58).
Base64 encode or decode a string — base64 encoder/decoder (body {mode:encode|decode,input}).
Hex encode or decode text — hex string encoder/decoder.
Decode a JWT — parse header and payload claims without a key (no signature verification).
Explain a cron expression (5 fields, names like mon-fri, or @daily) in plain English and list its next run times in any UTC offset. Use to check schedules before deploying jobs.
Your public IP address as the server sees it, IPv4/IPv6, network prefix, operator (ASN) and registration country, plus your user agent. Check where an agent exits from or whether a proxy/VPN works.
Purchase and download the Broken Key Remapper software (one-time license).
Regex tester, test. Run a JavaScript regular expression against a text and return every match with its index and capture groups (named groups included). Pattern up to 300 characters, text up to 5,000; patterns with neste...
Loan and mortgage calculator. Monthly payment of an amortised loan or mortgage from the amount, the annual interest rate and the term, plus the total paid, the total interest and the first months of the repayment schedul...
Color palette generator. Build a colour palette from one hex colour: complementary, analogous, triadic, split-complementary and tetradic harmonies (hue rotations at the same saturation and lightness), plus six shades fro...
Business days between dates. Count business (working) days between two dates, skipping weekends and public holidays for the US, UK, Sweden, Germany, France, Norway, Denmark or Finland, and list the holidays skipped; or g...
HTML table to JSON. Extract every table from an HTML fragment into JSON: header cells become keys and each body row an object (or raw arrays when there is no header row), with captions, colspans repeated and entities dec...
Math expression calculator. Evaluate an arithmetic expression safely (parsed, never executed as code): + - * / % ^ and **, parentheses, factorial !, constants pi, e and tau, and functions sqrt, cbrt, abs, round, floor, c...
Phone number validation. Validate and format a phone number with the libphonenumber rules: whether it is valid and possible, the E.164 form, international and national formatting, country, calling code and line type (mob...
Favicon finder. Find a website's icons: every <link rel=icon>, shortcut icon, apple-touch-icon and mask-icon on the page with its size and type, the web app manifest link, and whether /favicon.ico exists, all as absolute...
Random riddle - the riddle text and its answer as separate fields, drawn from a curated pool; the response includes the pool size
Robots.txt inspection API for agents at $0.01 USDC. Call when you need crawl rules and sitemap hints before indexing or scraping a domain. Use for SEO preflight and polite crawlers via x402—no API key, no subscription.
Age calculator. Exact age from a date of birth in years, months and days, total days lived, the weekday of birth, and the date of and days until the next birthday, measured today (UTC) or on any date you give. Use for ag...
Compound interest calculator. Future value of savings or an investment with compound interest: starting amount, annual rate, years, compounding (yearly, quarterly, monthly or daily) and an optional contribution at the en...
Tip calculator. Tip and total for a bill at a tip percentage, split between any number of people, optionally rounding each share up to the next whole amount. Use for receipts, expense apps and group payments.
JSON schema from example. Infer a JSON Schema (draft 2020-12) from an example JSON value: types, nested object properties, required keys, array item shapes merged across all items, and string formats (date-time, date, em...
QR code generator. Generate a QR code for a URL or any text (UTF-8, up to 1,000 characters) as a scalable SVG plus a ready-to-embed data URL, at error correction L, M (default), Q or H. Use to put a link, Wi-Fi string or...
Lorem ipsum generator. Lorem ipsum placeholder text: 1-20 paragraphs of 1-10 sentences, starting with the classic "Lorem ipsum dolor sit amet". The same seed always gives the same text. Use to fill mock-ups, templates an...