Classic ciphers - Caesar with any shift, ROT13, Atbash and Vigenere with a key, encode or decode, with all 25 Caesar candidates for brute force

Convert text or identifiers between camelCase, PascalCase, snake_case, kebab-case, CONSTANT_CASE, dot.case, path/case, Title Case and sentence case

Linear regression on two lists - slope, intercept, r, r-squared, standard errors, p-value, 95% slope interval, equation and a prediction for a new x

Text sentiment analysis - positive, negative, neutral or mixed with a -1 to 1 score and per-sentence scores

Extract emails, URLs, IPs, phone numbers, money, percentages, dates, hashtags, mentions, EVM, Bitcoin and Solana-style addresses and UUIDs from text

Extractive summary of a text - the most representative sentences by word frequency in original order, with scores, compression ratio and top terms

Inspect a string by code point - UTF-8 bytes, category, script, normalization changes, and warnings for zero-width, bidi and mixed-script lookalike text

Readability scores for English text - Flesch reading ease, Flesch-Kincaid, Gunning Fog, SMOG, ARI and Coleman-Liau, grade level, reading time and advice

Stellar account lookup - XLM balance, trustlines with issuer and limit, signers with weights, thresholds, flags, sponsorships and a locked-account check

Tezos account lookup via TzKT - XTZ balance, staked amount, baker delegation, reveal status, tokens held, transaction count and first and last activity

Top holders of an ERC-20 token with labels, balances and share of supply plus top 1, 5, 10 and 20 concentration and a concentration level from Blockscout

EVM address profile from Blockscout - name, ENS, contract and verified status, proxy type, tags such as exchanges, balance, token details and activity counts

Credit card payoff time from balance, APR and a fixed payment - months, total interest, total paid and what share of payments goes to interest

Kelly criterion bet sizing from win probability and odds - full, half and quarter Kelly, expected log growth, break-even win rate and a verdict

Minecraft Java server status - online flag, player count and sample, version, software, MOTD, plugin and mod counts and resolved IP and port

Convert an ISO 8601 duration like P1DT2H30M or PT90M to seconds, minutes, hours, days and plain words, or turn seconds into a duration string

Word frequency analysis - top words and repeated bigrams without stopwords, unique and total words, lexical diversity and average word length

Solve implied volatility from an observed option price using Black-Scholes, with delta, vega, a volatility regime label and the pricing error

Recent New Zealand earthquakes from GeoNet - magnitude, depth, felt intensity (MMI), nearest locality, time and coordinates, filterable by intensity

Philadelphia SEPTA Regional Rail real-time arrivals for a station - line, destination, status and track