# Clean.tools

> Fast, single-purpose utilities for developers, agents, and everyday tasks.
> The web tools run entirely in the visitor's browser (no uploads, no accounts,
> no tracking). The API/MCP tools are read-only pure functions: requests are
> processed in memory and never written to storage or logs.

## API and MCP (for AI agents and scripts)

42 tool engines are exposed as an authless, free MCP server and REST API.
Most tools are deterministic: same input, same output. The generator tools
(uuid_v4, generate_id, random_number, generate_password) use cryptographic
randomness instead. Nothing is retained; only anonymous per-tool call counters are kept.
Rate limit: about 60 requests/minute per caller — on HTTP 429, honor
Retry-After and add jitter.

- [MCP server (streamable HTTP, stateless)](https://mcp.clean.tools/mcp): add this URL to any MCP client, no key
- [Slim mounts](https://mcp.clean.tools/mcp?tools=explain_cron,convert_timezone): ?tools= mounts a subset to save agent context
- [OpenAPI 3.1 spec](https://api.clean.tools/openapi.json): canonical machine description of every REST endpoint
- [REST endpoints](https://api.clean.tools/v1/tools): POST https://api.clean.tools/v1/<tool>, JSON in, JSON out
- [npm stdio bridge](https://www.npmjs.com/package/@clean-tools/mcp): npx @clean-tools/mcp for stdio-only clients
- [Developers guide](https://clean.tools/developers/): copy-paste setup for Claude Code, Claude Desktop, Cursor, and more

Claude Code one-liner:
  claude mcp add --scope user --transport http clean-tools https://mcp.clean.tools/mcp

### Date and time tools

- [explain_cron](https://api.clean.tools/v1/explain_cron): explain a 5-field cron expression and compute its exact next runs (UTC)
- [validate_cron](https://api.clean.tools/v1/validate_cron): validate cron syntax, returning the specific error and expanded per-field values
- [expand_rrule](https://api.clean.tools/v1/expand_rrule): build an RFC 5545 RRULE from options, describe it, and expand occurrences
- [convert_timezone](https://api.clean.tools/v1/convert_timezone): convert a wall-clock time between IANA zones, DST-correct
- [strftime_preview](https://api.clean.tools/v1/strftime_preview): render a strftime format string for a given time (UTC)
- [convert_timestamp](https://api.clean.tools/v1/convert_timestamp): epoch (s/ms/us) <-> ISO-8601 <-> human, rendered in any IANA zone

### Finance tools

- [amortization_schedule](https://api.clean.tools/v1/amortization_schedule): fixed-rate loan payment plus year-by-year amortization
- [tvm_solve](https://api.clean.tools/v1/tvm_solve): solve time-value-of-money for N, I/Y, PV, PMT, or FV
- [compound_interest](https://api.clean.tools/v1/compound_interest): project growth with compounding and monthly contributions
- [apr_calc](https://api.clean.tools/v1/apr_calc): nominal-to-APY conversion or true installment-loan APR
- [interest_rate](https://api.clean.tools/v1/interest_rate): solve the rate that grows a principal to a target
- [percentage](https://api.clean.tools/v1/percentage): percent-of, is-what-percent, and percent-change math
- [tip](https://api.clean.tools/v1/tip): tip amount and per-person bill split

### Text and data tools

- [diff_text](https://api.clean.tools/v1/diff_text): line-level LCS diff with added/removed/unchanged lines
- [test_regex](https://api.clean.tools/v1/test_regex): run a JavaScript regex and return every match, index, and group
- [convert_data](https://api.clean.tools/v1/convert_data): convert tabular data between JSON, CSV, TSV, and XML
- [convert_case](https://api.clean.tools/v1/convert_case): re-case text (camel, snake, kebab, title, sentence, constant)
- [count_text](https://api.clean.tools/v1/count_text): Unicode-aware word, character, sentence, and paragraph counts
- [encode_decode](https://api.clean.tools/v1/encode_decode): URL, HTML-entity, Base64, and Unicode escape encode/decode
- [render_markdown](https://api.clean.tools/v1/render_markdown): Markdown to sanitized, XSS-safe HTML
- [lorem_ipsum](https://api.clean.tools/v1/lorem_ipsum): deterministic placeholder text by paragraphs, sentences, or words
- [redact_text](https://api.clean.tools/v1/redact_text): replace sensitive terms with block characters (test/dev fixtures; for real secrets prefer the client-side web tool)
- [fancy_text](https://api.clean.tools/v1/fancy_text): map ASCII to styled Unicode glyphs (bold, script, monospace, ...)
- [format_sql](https://api.clean.tools/v1/format_sql): pretty-print SQL with dialect-aware quoting and keyword casing
- [format_json](https://api.clean.tools/v1/format_json): format, minify, or validate JSON, with duplicate-key and big-integer data-loss warnings
- [convert_yaml](https://api.clean.tools/v1/convert_yaml): YAML <-> JSON conversion (safe parsing, alias-bomb guarded)
- [query_json](https://api.clean.tools/v1/query_json): extract values from JSON with a JSONPath subset — exact answers on deep structures
- [slugify](https://api.clean.tools/v1/slugify): URL/filename-safe slugs with Unicode transliteration

### Developer tools

- [hash_text](https://api.clean.tools/v1/hash_text): SHA-1/SHA-256/SHA-512 hex digests of UTF-8 text
- [decode_jwt](https://api.clean.tools/v1/decode_jwt): decode (NOT verify) a JWT's header, payload, and expiry
- [luhn_validate](https://api.clean.tools/v1/luhn_validate): Luhn mod-10 checksum with per-digit working
- [convert_units](https://api.clean.tools/v1/convert_units): exact unit conversion across length, weight, temperature, volume, data, speed, area, time
- [generate_qr](https://api.clean.tools/v1/generate_qr): QR code module matrix plus ready-to-render SVG
- [uuid_v4](https://api.clean.tools/v1/uuid_v4): RFC 4122 v4 UUIDs, cryptographically random (not deterministic)
- [random_number](https://api.clean.tools/v1/random_number): secure unbiased random integers/decimals (not deterministic)
- [generate_password](https://api.clean.tools/v1/generate_password): strong random or memorable passwords, cryptographically random (test/dev fixtures; for real credentials prefer the client-side web tool)
- [generate_id](https://api.clean.tools/v1/generate_id): UUID v5/v7, ULID, Nano ID, plus timestamp decoding (v5/decode deterministic; the rest cryptographically random)
- [convert_number_base](https://api.clean.tools/v1/convert_number_base): exact base 2-36 conversion via BigInt (no precision loss)

### Color and design tools

- [color_palette](https://api.clean.tools/v1/color_palette): harmony palettes (complementary, triadic, ...) from one hex color
- [color_contrast](https://api.clean.tools/v1/color_contrast): WCAG 2.x contrast ratio with AA/AAA pass/fail
- [css_gradient](https://api.clean.tools/v1/css_gradient): ready-to-paste CSS linear/radial gradient from 2-5 stops
- [convert_color](https://api.clean.tools/v1/convert_color): one color in, hex + RGB + HSL + HSV + CMYK + OKLCH out

## Web tools (browser-only, nothing uploaded)

All processing happens client-side on the visitor's device: files, text,
images, and audio are never uploaded. Fonts and libraries are self-hosted
(no CDN or font-service fetches), and a service worker keeps the tools
working offline. Each tool lives at https://clean.tools/<slug>/.

Images and color: /image-resizer/ /image-cropper/ /image-compressor/
  /image-metadata/ /metadata-remover/ /color-picker/ /image-redact/
  /color-palette/ /gradient-generator/ /favicon-generator/ /color-contrast/
  /heic-to-jpg/ /png-to-svg/
PDF: /pdf-merge/ /pdf-split/ /image-to-pdf/ /pdf-metadata/
Text: /word-counter/ /case-converter/ /text-redact/ /diff-checker/
  /lorem-ipsum/ /fancy-text/ /markdown-preview/ /ocr/
Developer: /json-formatter/ /regex-tester/ /uuid-generator/ /hash-generator/
  /jwt-decoder/ /base64/ /encoder-decoder/ /cron/ /rrule/ /strftime/
  /password-generator/ /sql-formatter/ /mock-data/ /jwt-generator/
  /key-generator/
Data and files: /file-converter/ /file-compressor/ /unit-converter/ /yaml-json/
Finance: /tvm-calculator/ /interest-rate/ /apr-calculator/ /compound-interest/
  /mortgage-calculator/ /tip-calculator/ /percentage-calculator/
Time: /timezone/ /pomodoro/ /stopwatch/
Media and codes: /voice-recorder/ /audio-converter/ /qr-generator/ /qr-reader/
  /barcode-reader/
Fun and random: /random-number/ /coin-flip/ /prize-wheel/ /decision-wheel/ /team-generator/
  /dice-roll/ /magic-8ball/ /luhn/ /test-print/ /dad-joke/ /rubber-duck/
  /typing-speed-test/

## Other pages

- [Homepage](https://clean.tools/): every tool by category
- [Developers](https://clean.tools/developers/): API and MCP quickstart with copy-ready snippets
- [About](https://clean.tools/about/): what the site is and who makes it
- [Privacy](https://clean.tools/privacy/): the full privacy model
- [Sitemap](https://clean.tools/sitemap.xml): machine-readable list of all pages

## Contact

- Email: support@clean.tools