Health

Solve for pace, finish time or distance given the other two. Enter a known distance and either a finish time or a pace, and get the missing value plus speed and optional Riegel race predictions.

Text Processing

Convert text to Sentence case: capitalize the first letter of each sentence and lowercase everything else. Auto-restores the standalone pronoun "I".

Security

Generate cryptographically secure random key material driven by entropy budget — request N bits of entropy, get hex/base64/base64url output. Also supports custom-alphabet strings via crypto.randomInt (rejection-sampled, no modulo bias). Use this instead of Math.random()-based tools for any secret/key/token.

Security

Audit HTTP response headers for security compliance — parses the raw headers you paste (no network) and grades them against the OWASP secure-header set with value-level checks: HSTS max-age, CSP unsafe-inline/eval, X-Content-Type-Options, Referrer-Policy, Permissions-Policy, COOP/COEP/CORP and more. Outputs a letter grade (A+ to F) plus per-header findings with copy-ready fix recommendations.

Security

Split a secret into n shares where any k (the threshold) are required to reconstruct it — Shamir's k-of-n scheme over GF(256). Pure in-process cryptography (crypto.randomBytes for polynomial coefficients), no network. Split a password/key/passphrase into shares held by separate people, then combine any k of them to recover it. Confidentiality only — no authenticity.

Validation

Validate 7-character UK/Irish SEDOL securities identifiers with weighted mod-10 check-digit verification and SEDOL-7 structure breakdown.

Text Processing

Fetch an RSS or Atom feed by URL (or paste raw XML), parse it, sort items by publish date, deduplicate, apply a time window, and output a clean Markdown summary

Development

Preview Google SERP (pixel-accurate desktop & mobile truncation), X (Twitter) Card, and OpenGraph card side by side, with pre-launch SEO diagnostics

Media

Convert Panasonic RW2 RAW files to JPEG format. Automatically extracts image dimensions and metadata from the RAW file.

Media

Convert Panasonic RW2 RAW files to PNG format. Automatically extracts image dimensions and metadata from the RAW file.

Sports

Predict race times, calculate heart-rate zones, and build pace conversion tables from a recent race result

Math & Numbers

Calculate sample standard deviation from sample variance using the n - 1 denominator