Every API, one clean contract.

Hash/checksum text or binary (base64/hex) input: md5…sha3·blake2·crc32·adler32, optional HMAC keying → hex + base64 digests.

{
  "input": "hello world",
  "algo": "sha256"
}

Generate ids: uuid v4/v7/v1(MAC-safe)/v3/v5, ULID, nanoid — up to 100.

{
  "version": "v4",
  "count": 3
}

Encode/decode: base64(+url-safe), hex, URL (path/component/form), HTML entities, unicode-escape, json-string.

{
  "input": "Merhaba Dünya! 👋",
  "op": "base64"
}

Decode a JWT WITHOUT needing the key (header+payload+claims analysis); optionally verify the signature with a provided key. Decode-only — this API never signs tokens.

{
  "token": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkpvaG4gRG9lIiwiaWF0IjoxNTE2MjM5MDIyfQ.SflKxwRJSMeKKF2QT4fwpMeJf36POk6yJV_adQssw5c",
  "verify_key": "your-256-bit-secret"
}

Generate cryptographically-secure passwords (charset controls, ambiguity filter) + entropy strength score; or score a provided password with `check`.

{
  "length": 24,
  "count": 2
}

Explain a cron expression in plain language (15 locales) + compute the next N run times in any IANA timezone (DST-correct).

{
  "expression": "*/15 9-17 * * 1-5",
  "runs": 3,
  "tz": "UTC",
  "from_time": "2026-06-10T12:00:00+00:00"
}

URL-safe slug from any-script text (CJK/Cyrillic/Arabic → ASCII via anyascii transliteration).

{
  "input": "Çok Güzel Bir Başlık — 2026!"
}

Test a regex against text: matches + groups + named groups, optional replace. User patterns run with a hard 1s timeout (ReDoS-guarded) + size caps.

{
  "pattern": "(\\w+)@([\\w.]+)",
  "input": "mail [email protected] now"
}

Pretty-print, minify or validate JSON / YAML / XML / SQL (string-level; file/data CONVERSION lives in the file-convert API).

{
  "input": "{\"b\":1,\"a\":[1,2]}",
  "type": "json",
  "op": "pretty",
  "sort_keys": true
}

Convert structured data between JSON / YAML / CSV / XML at the string level (paste-in, ≤512KB). CSV↔JSON is tabular (array of flat objects). For file/Excel/multi-MB conversion use the file-convert API.

{
  "input": "[{\"id\":1,\"name\":\"a\"},{\"id\":2,\"name\":\"b\"}]",
  "from": "json",
  "to": "csv"
}

Generate a QR code as SVG (text), base64-PNG (text data-URI), or terminal ASCII — all textual output, no binary asset. Up to QR version 40.

{
  "input": "https://reefapi.com",
  "kind": "svg"
}

Parse any CSS color (hex/rgb()/hsl()/name) → every format + CSS3 name + luminance; optional second color → WCAG 2.x contrast ratio + AA/AAA.

{
  "input": "#1a2b3c",
  "contrast_with": "#ffffff"
}

Generate fake/test records (Faker, 70+ locales): preset bundles (person/address/company/internet/profile/product/lorem) or a custom field→type schema; seed for reproducible output.

{
  "preset": "person",
  "count": 2,
  "seed": 42
}

Unified diff between two texts + change stats + similarity ratio.

{
  "a": "one\ntwo",
  "b": "one\n2"
}

Algorithmic text analysis (no LLM): language detect (97 langs) · readability (Flesch & co) · profanity flag/censor · keyword extraction · full stats. Pick checks or get all.

{
  "input": "The quick brown fox jumps over the lazy dog. The fox is fast."
}

Parse/convert any timestamp ('now', unix s/ms/µs, ISO-8601, RFC-2822) → every format + timezone conversion + relative time.

{
  "value": "1718000000",
  "tz": "Europe/Istanbul"
}

Convert identifier/text casing: camel·pascal·snake·kebab·constant·dot·title·sentence·upper·lower (+ detected input case).

{
  "input": "getUserProfileURL",
  "target": "snake"
}

Convert integers between bases 2-36 (arbitrary precision; 0x/0b/0o prefixes accepted).

{
  "input": "ff",
  "from_base": 16,
  "to_base": 10
}

Render CommonMark+tables markdown → sanitized HTML (raw HTML escaped, XSS-safe) + heading TOC with slugs.

{
  "input": "# Hello\n\nworld **bold**\n\n## Sub Title"
}

Parse a User-Agent string → browser/OS/device families + versions + bot flag (uap-core database).

{
  "input": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/125.0.0.0 Safari/537.36"
}

Run up to 100 mixed dev-utils calls in one request.

{
  "items": [
    {
      "action": "hash",
      "params": {
        "input": "abc",
        "algo": "md5"
      }
    },
    {
      "action": "base_convert",
      "params": {
        "input": "1010",
        "from_base": 2
      }
    },
    {
      "action": "encode",
      "params": {
        "input": "x",
        "op": "nope"
      }
    }
  ]
}