SimplyUtils

Encode text (as UTF-8) to Base64, or decode Base64 back to text, and return the result. Decoding accepts standard and URL-safe alphabets and ignores whitespace; invalid Base64 returns an error. Bytes that are not valid UTF-8 are shown as replacement characters. Input up to 100 KB.

Convert a Unix timestamp or a date to Unix seconds, Unix milliseconds, ISO 8601 (UTC), an HTTP-style UTC string and a readable date in the chosen time zone. Numbers with 13 or more digits are read as milliseconds, shorter ones as seconds. Dates without a time zone are read as UTC. Errors are returned for unreadable dates and unknown time zones.

Convert a number between two units of the same category and return a line such as "5 mi = 8.04672 km" (up to 10 significant digits). Units are matched by symbol or name, case-insensitive. Errors are returned for unknown units, units from another category, non-numeric values and temperatures below absolute zero. Months are 1/12 of a 365-day year. Units by category (symbols): length: m, km, mi, ft, in, cm, mm, yd, nmi; weight: kg, g, lb, oz, t, mg, st; temperature: °C, °F, K; volume: L, mL, gal, fl oz, cup, tbsp, m³; speed: km/h, mph, m/s, kn, ft/s; area: m², km², mi², ft², ac, ha; data: B, KB, MB, GB, TB, bit, KiB, MiB, GiB, TiB; time: s, min, h, d, wk, mo, yr, ms.

Count words, characters (with and without spaces), sentences and paragraphs, and estimate reading time at 238 words per minute. Words are runs of letters or digits in any language; hyphenated words and contractions count once. Paragraphs are separated by blank lines. Input up to 100 KB.

Validate JSON and return it pretty-printed or minified, optionally with object keys sorted A-Z (recursively; array order is kept). Returns the formatted JSON as text. Invalid JSON returns an error naming the problem and its position. Input up to 100 KB.

Generate random passwords with Node's cryptographically secure generator. Each enabled character set appears at least once and the result is shuffled. Returns one password per line; every call gives new results. An error is returned if all character sets are turned off. Passwords are not stored or logged.

Make a static QR code for a link or any text, up to 800 UTF-8 bytes. Returns a 512 px PNG image plus the SVG markup. The data is stored in the code itself, so it never expires and needs no account. Light-on-dark colors are allowed, but some older scanners need dark on light. Errors are returned for empty text, content over 800 bytes, or colors that are not six-digit hex.

Generate random version 4 UUIDs (RFC 9562) in lowercase 8-4-4-4-12 form, one per line. Every call gives new values.

Hash text (encoded as UTF-8) and return a line such as 'sha256: ba78...' with the lowercase hex digest. The same input always gives the same hash. MD5 and SHA-1 are only for checksums, not security; do not use plain hashes to store passwords. Input up to 100 KB.

Run a JavaScript (ECMAScript) regular expression against text. Returns the match count and, for each match, the matched text, its 0-based index, numbered capture groups and named groups. Returns 'No matches.' when nothing matches. All matches are listed (the g flag is added automatically), up to 200. Invalid patterns or flags return an error explaining why; patterns that run longer than 0.5 seconds are stopped with an error. Text up to 100 KB.