Build single + bulk campaign URLs; preserves existing query params.
Turn an idea into a paste-ready tool spec (problem → inputs/outputs → tests → monetization).
Multiply assumptions into a back-of-the-envelope estimate; share via URL hash (client-side).
Hash text/files to create receipts you can cite.
Quickly compare two texts for small edits or tampering.
Minify SVG + optionally add viewBox (client-side; strips scripts).
Generate a multi-size favicon.ico from a PNG (client-side; no uploads).
Paste log lines → normalize timestamps, sort events, and compute deltas (client-side; no uploads).
Queueing theory for SREs: utilization, mean wait, mean queue length (client-side).
Multi-server queue: P(wait), mean queue length, and mean wait (client-side).
Percentiles for wait time + time-in-system under M/M/1 assumptions (client-side).
Test JS regexes locally; see matches, groups, and highlights.
Generate passwords locally; no server calls.
Generate strong, memorable passphrases (adjective+noun style) locally.
Shannon + min-entropy stats for pasted text/passwords (client-side; no uploads).
Scrabble / Words With Friends scoring + letter frequency stats (client-side; no uploads).
Solve Sudoku puzzles locally (paste 81 chars or type digits). Client-side; no uploads.
Split a secret into N shares with threshold K (client-side; no uploads).
Canonical JSON → SHA-256 → Ed25519 sign/verify (client-side).
Verify receipt:v1 against payload (canonicalize+hash+Ed25519 verify).
Redact emails/phones/IPs/cards/JWTs/tokens from text logs locally (no uploads).
Verify Stripe/GitHub-style webhook HMAC signatures locally (no uploads).
Generate a strict Content-Security-Policy header/meta from readable directives (client-side).
Compute CSP 'sha256/384/512-…' tokens for inline scripts/styles (client-side; no uploads).
Generate a sample nonce + paste-ready CSP/HTML and minimal server-side patterns (Express/nginx/Apache).
Paste CSP violation logs/JSON reports → suggested directive updates (client-side).
Generate Report-To header JSON + matching CSP report-to directive (client-side).
Endpoint URL → Report-To header + CSP Report-Only header + clean enforce CSP (client-side).
Pretty-print + validate JSON to avoid copy/paste failures.
Infer draft 2020-12 JSON Schema from a sample JSON document (no uploads).
Convert CSV/TSV to JSON + inferred column types (no uploads).
Validate ISBN-10/13 checksums and convert between formats (client-side; no uploads).
Validate IMEI/account-like IDs with Luhn; compute check digit + fix suggestion (client-side).
A minimal unit converter for quick ops math.
Scale ingredient amounts (fractions + mixed numbers) and format a clean shopping list (client-side).
Timezones + timestamps; keep coordination precise.
Generate a calendar .ics event file locally (copy/download).
Generate ULIDs locally for receipts and queues.
Compute uptime % and allowed downtime for an SLO window.
IPv4 subnet math: network/broadcast/range/mask/host counts (client-side).
Run Brainf*** programs locally with a step limit (client-side; no uploads).
Decode JWT header/payload locally (no signature verification).
Encode/decode locally (handy for JWT parts); supports base64url without padding.
Encode/decode Base32 (RFC 4648) locally; forgiving decode for human input.
Generate QR codes (SVG/IMG/ASCII) locally for URLs, Wi‑Fi strings, receipts.
Encode/decode Base58 locally (Bitcoin alphabet) + Base58Check checksum builder/verifier.
Encode/decode + checksum verify for Bech32 and Bech32m (SegWit-style strings). Client-side.
Run-length encode/decode UTF-8 bytes to compact tokens (client-side; no uploads).
Convert text ↔ UTF-8 hex bytes + offsets + ASCII view (client-side; no uploads).
Extract dominant HEX colors from an image (client-side; no uploads).
Snowball/avalanche projection + downloadable schedule CSV (client-side).
Compare total costs + breakeven year with simple assumptions (client-side).
401k/IRA intuition tool: after-tax outcome + simple break-even model (client-side).
WCAG contrast ratio + AA/AAA pass/fail for normal/large text (client-side).
Parse a 5-field cron expression and preview the next run times (client-side).
Shift subtitle timestamps by a fixed offset (ms). Paste → shift → download. Client-side.
Convert SRT↔VTT and optionally shift timestamps. Client-side; no uploads.
Great-circle distance, initial bearing, and midpoint between two lat/lon points (client-side).
Find near-duplicate lines using SimHash + Hamming distance (client-side; no uploads).
Unit economics: contribution margin + break-even units + units for target profit (client-side).
Project customers and MRR over time with churn + new customers; presets + share links + CSV export (client-side).
Founders + option pool + one priced round: ownership %, dilution, implied price/share (client-side).
Encode text ↔ Morse; supports A–Z, 0–9, common punctuation. Client-side.
Estimate sample size for a conversion-rate A/B test (alpha/power/MDE + runtime from daily traffic). Client-side.
Rank options vs weighted criteria; shareable link + CSV export. Client-side.
Estimate meeting cost (headcount × rate × time) and copy a paste-ready summary.
Generate a work/break schedule and download a calendar .ics. Client-side; no uploads.
Dot grid / graph / lined paper as a true-size SVG you can print at 100% (client-side; no uploads).
Deterministic identicon from any string (SHA-256 via WebCrypto) with SVG/PNG + share links (client-side; no uploads).
Convert text between snake/kebab/camel/Pascal/CONSTANT/title/sentence (client-side; no uploads).
Convert note names (A4, C#3, Db5) ↔ Hz (12‑TET); scale generator + bulk mode. Client-side.
Exact distribution + tail probabilities for expressions like d20, 2d6+1 (client-side; no uploads).
Randomly generate plausible-sounding “AI + X” pitches from extensive wordlists (client-side; no tracking).
Principle: if it can be done client-side, it should be. Tools must be wget/curl-safe and not depend on third-party scripts.
/skills.html with a clear artifact and a test case.