MAD Synapse · Utils

Make a QR code for any text, URL, Solana Pay / wallet address or Wi-Fi login — as a PNG (base64 data URL) or SVG, with size, margin, colours and error correction. Rendered on our server. For Wi-Fi pass wifi_ssid + wifi_password; for Solana Pay pass a solana: URI as text. Price: free. Errors: returns isError with a message for invalid input or an upstream failure (not charged).

Hash data (SHA-256/512, SHA3, Keccak-256, BLAKE2, MD5, SHA-1, RIPEMD-160, HMAC) and convert between utf8, hex, base64, base64url and base58 — exact, in one call. Useful for signatures, content addressing, EVM selectors (keccak of a function signature), and decoding blobs agents are handed. Input can itself be hex/base64/base58. Price: free. Errors: returns isError with a message for invalid input

Validate JSON data against a JSON Schema (draft-07/2019-09/2020-12, formats like email/uri/date-time) and get every error with its exact path — check tool I/O before acting on it. Ajv, strict about types, all errors reported. Pass data and schema as JSON values (or JSON strings). Price: free. Errors: returns isError with a message for invalid input or an upstream failure (not charged).

Explain a cron expression in plain English and list its next N run times in any time zone — catch a schedule mistake before it fires at 3 am. Supports 5-field and 6-field (seconds) cron, ranges, steps, L/W/#, and nicknames (@daily, @hourly…). Price: free. Errors: returns isError with a message for invalid input or an upstream failure (not charged).

Convert Markdown to clean HTML (GitHub-flavoured: tables, task lists, fenced code) or HTML back to Markdown. marked for md→html, Turndown for html→md. Scripts/styles are dropped on html→md. Price: free. Errors: returns isError with a message for invalid input or an upstream failure (not charged).

Diff two texts: unified diff (patch format), a line/word-level change list, and similarity % — compare versions of a doc, config or code. jsdiff. mode=lines gives a unified patch; mode=words gives word-level changes for prose. Price: free. Errors: returns isError with a message for invalid input or an upstream failure (not charged).

Convert between units of length, mass, volume, temperature, speed, area, time, data size, energy, power, pressure, frequency and more — or list every unit a value converts to. Exact conversion tables (convert-units). Use abbreviations: m, km, mi, ft, kg, lb, oz, l, gal, C, F, K, km/h, mph, knot, B, KB, MB, GB (binary, 1 GB = 1024 MB), J, kWh, W, Pa, bar, psi, Hz… Price: free. Errors: returns isErr

Decode a JSON Web Token's header and claims, show issued/expiry times in plain dates and whether it has expired — optionally verify an HS256/384/512 signature with a secret. Decoding does not need the key. Never paste production secrets into third-party tools you do not trust; verification here is local and nothing is stored or logged. Price: free. Errors: returns isError with a message for invali

Cryptographically secure randomness: UUID v4/v7, passwords, API-key-style tokens, integers in a range, dice, coin flips, or a fair shuffle / pick from a list. Node's CSPRNG. Output is generated fresh per call and never stored or logged. Price: free. Errors: returns isError with a message for invalid input or an upstream failure (not charged).

Count characters, words, sentences, lines and paragraphs, estimate LLM tokens, reading time and readability (Flesch), and pull out every URL, email, @handle, #tag, number and crypto address. Token count is an estimate (~4 characters per token for English; code and non-Latin scripts differ). Extraction uses strict patterns; EVM addresses are checksum-validated. Price: free. Errors: returns isError