Clean.tools

Showing 25 of 42 from the live probe.

• Cron Explainer

  Use this when you need to understand or schedule a 5-field cron expression. Prefer this over reasoning about cron semantics yourself (a documented LLM failure mode): it correctly handles ranges, lists, steps, month/day names, and the tricky day-of-month OR day-of-week rule. Deterministic: same input, same output. Returns a plain-English description, the expanded matching values per field, and the next run times computed in UTC (pass `now` to fix the reference point, `count` for how many). Exampl

• Cron Validator

  Use this when you need to check whether a 5-field cron expression is well-formed, instead of guessing. Prefer this over reasoning about cron syntax yourself (a documented LLM failure mode). Deterministic: same input, same output. On success returns valid=true, the normalized expression, and the expanded matching values per field; on failure returns valid=false with a specific error (out-of-range value, reversed range, invalid step, wrong field count, or a field that matches nothing). Example: '9

• RRULE Expander

  Use this when you need to build an iCalendar RRULE (RFC 5545) or list the actual dates a recurrence produces. Prefer this over computing recurring dates yourself (a documented LLM failure mode): it correctly handles INTERVAL, COUNT/UNTIL exclusivity (COUNT wins), BYDAY with ordinals (e.g. the 2nd Monday), BYMONTH, and month-length edge cases. Deterministic: same input, same output; start is interpreted as UTC. Returns the RRULE string, a plain-English description, and up to 10 (or COUNT) occurre

• Time Zone Converter

  Use this when you need to convert a wall-clock date-time between IANA time zones with correct DST handling. Prefer this over doing timezone math yourself (a documented LLM failure mode): it uses the runtime's IANA database so offsets and daylight-saving transitions are exact. Deterministic: same input, same output. Returns the corresponding UTC instant, both zones' UTC offsets in minutes at that instant, and the converted local time. Example: {datetime:'2026-07-08T14:30', fromTz:'America/New_Yor

• strftime Preview

  Use this when you need to know exactly what a C/POSIX strftime pattern (%Y %m %d %H %M %S %A %B %j %z etc.) produces. Prefer this over guessing the output yourself. Deterministic: same input, same output; the reference time is formatted in UTC (%Z is 'UTC', %z is '+0000', defaults to current time when datetime is omitted). Unknown directives pass through literally. Example: {format:'%A, %B %e, %Y at %I:%M %p', datetime:'2026-07-08T14:30:45'} -> 'Wednesday, July 8, 2026 at 02:30 PM'.

• Amortization Schedule

  Use this when you need a fixed-rate loan or mortgage's level monthly payment plus a year-by-year amortization schedule (principal paid, interest paid, remaining balance) rather than doing the amortization arithmetic yourself. Uses the standard payment formula and handles the 0% case (payment = principal / months, all principal). annualRate is a percent (6.5 = 6.5%); years is 1-50. Deterministic: same input, same output. Example: principal 300000, annualRate 6.5, years 30 -> monthlyPayment 1896.2

• TVM Solver

  Use this when you have four of the five time-value-of-money variables (N periods, I/Y annual rate percent, PV, PMT, FV) and need the fifth - annuity, loan, or investment problems - instead of solving the equation by hand. Solving for I/Y uses Newton-Raphson (no closed form). Supports compoundingPerYear and annuityDue (payments at the beginning of each period). Follows the cash-flow sign convention (outflows negative). Deterministic: same input, same output. Example: solveFor 'fv', n 120, iy 6, p

• Compound Interest Projection

  Use this when you need to project a principal's growth under compound interest, optionally with recurring monthly contributions, returning the final balance and a year-by-year breakdown rather than estimating compound growth yourself. Iterates month-by-month for accuracy; contributions are added at the start of each month; compoundingPerYear defaults to 12. annualRate is a percent; years is 1-200. Deterministic: same input, same output. Example: principal 10000, annualRate 7, years 10, monthlyCo

• APR / APY Calculator

  Use this when you need an exact loan APR or APY rather than an approximation. Two modes. mode="loan" (default): solve the true APR of an installment loan from amount financed, monthly payment, term, and upfront fees — Reg-Z style, fees discounted against the amount received, solved by Newton-Raphson. mode="rate": convert a nominal annual rate to APY for a given compounding frequency. Deterministic: same input, same output. Example: mode="loan", loanAmount=20000, monthlyPayment=450, termMonths=60

• Interest Rate Solver

  Use this when you need the exact interest rate that grows a principal to a target amount over a set number of years. type="compound" (default) uses the closed-form nth-root formula for the given compounding frequency; type="simple" uses linear growth. Requires target greater than principal and all values positive. Returns the annual rate as a percent plus the interest earned and the growth multiple; compoundingPerYear is null for simple interest. Deterministic: same input, same output. Example:

• Hash Text

  Use this when you need the exact SHA-1, SHA-256, and/or SHA-512 hex digest of a UTF-8 string — never recall or guess a hash, since digests cannot be produced from memory. Deterministic: same input, same output. Pass `algorithm` for a single digest or `algorithms` for a subset; the default computes all three. The empty string is valid, and `byteLength` reports the UTF-8 encoded byte length of the input. Example: text "hello" with algorithm SHA-256 -> byteLength 5, hashes["SHA-256"] = "2cf24dba5fb

• Text Diff

  Use this when you need an exact line-level diff between two blocks of text instead of eyeballing the differences. Deterministic: same input, same output. Computes a longest-common-subsequence diff and returns every line tagged added, removed, or unchanged, plus per-category counts. Example: original "a\nb", modified "a\nB" -> added 1, removed 1, unchanged 1, with lines [{type:"unchanged",text:"a"},{type:"removed",text:"b"},{type:"added",text:"B"}]. Trailing edits produce separate removed+added l

• Regex Tester

  Use this when you need the true matches of a JavaScript regular expression rather than predicting regex behavior yourself, which is easy to get wrong. Deterministic: same input, same output. Returns every match with its index, length, matched text, positional capture groups (null for a group that didn't participate), and named groups (an object, or null when the pattern has none). Without the g flag only the first match is returned; with g all matches are collected, capped at 10,000 with truncat

• Convert Data

  Use this when you need to convert tabular data between JSON (array of objects), CSV, TSV, and XML instead of hand-transforming it. Deterministic: same input, same output. Handles quoted CSV fields (embedded commas, escaped "" quotes), flattens nested objects into dotted keys (b.x), and takes the union of keys across all rows so ragged data still lines up in columns. CSV/TSV input needs a header row plus at least one data row; JSON input must be an array of objects. Example: {from:'csv', to:'json

• Luhn Validate

  Use this when you need to check whether a number passes the Luhn (mod-10) checksum used by credit cards and many identifier numbers, instead of computing the doubling-and-summing by hand. Deterministic: same input, same output. Spaces and dashes are stripped first; any remaining non-digit character is an error. Returns the boolean result plus the full per-digit working, one steps entry per digit in original order (the digit, its transformed value after Luhn doubling, and whether that position wa

• Convert Units

  Use this when you need to convert a value between units within one category (length, weight, temperature, volume, data, speed, area, time) instead of doing conversion arithmetic yourself. Deterministic: same input, same output. Temperature uses the correct offset formulas (Celsius/Fahrenheit/Kelvin), not a naive ratio, and unit keys are case-sensitive (e.g. km, lb, celsius, MB) while the category name is case-insensitive. Example: {category:'length', value:5, from:'km', to:'mile'} -> result 3.10

• UUID v4 Generator

  Use this when you need RFC 4122 version-4 UUIDs — always generate them here rather than fabricating one, so the version and variant bits and the randomness are correct. Cryptographically random via Web Crypto (NOT deterministic): every call returns fresh values. `count` (default 1, max 100) sets how many; `uppercase` returns upper-case hex (lowercase by default). Example: {count: 1} -> count 1, uuids[0] = "2c549b2f-497c-47fc-a1b6-c24bc69667e5".

• Random Number

  Use this when you need to draw cryptographically secure random integers or decimals in a range using unbiased rejection sampling — prefer it over inventing 'random' numbers, which are neither uniform nor safe. Cryptographically random via Web Crypto (NOT deterministic). Bounds are inclusive; a reversed min/max is auto-swapped; integer mode rounds the bounds inward; `decimals` sets the decimal places in decimal mode. `count` (default 1, max 100). The returned `min`/`max` are the normalized effect

• Generate Password

  Use this when you need strong passwords with Web Crypto randomness: mode="random" builds character-set passwords (length plus uppercase/lowercase/numbers/symbols toggles); mode="memorable" builds word passphrases (words, separator, addNumber, addSymbol). Cryptographically random via Web Crypto (NOT deterministic). For test/dev fixtures — for real credentials prefer the client-side web tool at clean.tools/password-generator/ so the password never crosses the network. Example: {mode: "random", len

• Decode JWT

  Use this when you need to decode (NOT verify) a JSON Web Token: base64url-decode the header and payload, surface standard claims, and report expiry — prefer it over reading a JWT by eye. The decode is deterministic, but `expired`/`notYetValid` are compared against the current clock unless you pass `now` (ISO) to pin the reference time. The signature is never checked (`signatureVerified` is always false), so never authorize anything based on the output. `expired`/`notYetValid` are booleans when `

• Encoder / Decoder

  Use this when you need to encode or decode text and want multi-byte and entity edge cases handled correctly rather than doing it by hand. Deterministic: same input, same output. The mode selects the operation: url-encode/url-decode (percent-encoding), html-encode/html-decode (entity table plus numeric character references), base64-encode/base64-decode (UTF-8 safe; decode tolerates URL-safe alphabet, whitespace, and missing padding), and unicode-encode/unicode-decode (\uXXXX and \u{...} escapes f

• Text Counter

  Use this when you need exact word, character, sentence, and paragraph counts instead of estimating. Deterministic: same input, same output. Uses Unicode-aware segmentation (Intl.Segmenter): characters are grapheme clusters, so an emoji or an accented letter counts as one; words are word-like segments; sentence splitting is abbreviation-aware (Dr., etc., won't end a sentence). charactersNoSpaces counts graphemes after stripping whitespace, and paragraphs are blocks separated by blank lines. Examp

• Generate QR Code

  Use this when you need to turn text or a URL into a real, scannable QR code rather than describing one. Deterministic: same input, same output. Byte mode, error-correction level M, versions 1-10 auto-selected by length (up to 213 bytes); the encoder scores all 8 mask patterns and keeps the lowest-penalty one. Returns both the module matrix as rows of 0/1 (1 = dark module) and a ready-to-render self-contained SVG string. moduleSize sets SVG pixels per module (default 10) and quietZone the border

• Convert Case

  Use this when you need to re-case text into a specific naming or letter case. Given `text` and a target `case` (upper, lower, title, sentence, camel, snake, kebab, or constant), returns the converted string. Smart word tokenization splits camelCase, snake_case, kebab-case, and whitespace, so a phrase in any style re-cases consistently; title case honors an editorial stop-word list and preserves ALL-CAPS acronyms. Empty text returns an empty result. Deterministic: same input, same output. Example

• Fancy Text

  Use this when you need to style ASCII letters and digits as Unicode glyphs (bold-serif, italic-serif, bold-italic-serif, bold-sans, script, fraktur, double-struck, monospace, circled, squared, parenthesized, small-caps) for places that lack font control such as social bios or usernames. Pass a `style` and `text` to get the transformed string; characters outside A-Z, a-z, and 0-9 (spaces, punctuation, emoji) pass through unchanged. Omit `style` to receive the list of valid style keys instead of t