devpack API Documentation

Use devpack’s most useful tools from your own code. The API is free, needs no sign-up and returns JSON. Every endpoint accepts GET with query parameters or POST with a JSON body.

All endpoints

Quick start

The base URL is https://devpack.app/v1.

curl "https://devpack.app/v1/hash?text=hello"

JavaScript

const res = await fetch('https://devpack.app/v1/uuid?count=2');
const { ok, data, error } = await res.json();
if (!ok) throw new Error(error.message);
console.log(data.uuids);

Python

import requests

r = requests.post('https://devpack.app/v1/json-format', json={'json': '{"a":1}'})
print(r.json()['data']['formatted'])

Send secrets, such as tokens or passwords, in a POST body rather than the URL, because URLs can end up in logs. The API can be called directly from a browser (CORS is open). A machine-readable OpenAPI description is also available.

Responses

Successful calls return {"ok": true, "data": {…}}. Failed calls return an error with a stable code:

{
  "ok": false,
  "error": { "code": "invalid_request", "message": "Missing required parameter: text" }
}

Status	Code	Meaning
400	`invalid_request`	A parameter is missing or invalid
401	`invalid_key`	The API key isn’t valid
404	`not_found`	Unknown endpoint
429	`rate_limited`	A limit was reached. Wait for `Retry-After` seconds
502	`upstream_error`	The site or service being checked failed
503	`unavailable`	The API is temporarily off

Rate limits

No key is needed. Free use is counted per IP address:

Type	Limit
Text, generators and conversion	60 requests per minute
Network checks	15 requests per minute
All requests together	1,000 requests per day

Each response includes X-RateLimit-Limit, X-RateLimit-Remaining, X-RateLimit-Reset, X-RateLimit-Daily-Limit and X-RateLimit-Daily-Remaining headers.

API keys

Keys aren’t needed for free use. If you’ve been given one, send it in a header:

curl -H "X-API-Key: YOUR_KEY" "https://devpack.app/v1/uuid"

Need higher limits? Get in touch.

Fair use and privacy

The API is provided as is, under our Terms. Only check sites you’re allowed to test, and don’t use the API to overload any service. We don’t store the text you send. Network checks can only reach public addresses. Limits and endpoints may change; breaking changes will go in a new version.

Text and data

`/v1/hash`

GETPOST

Hash text with MD5 or SHA.

Parameters

Name	Type	Required	Description
`text`	string	Yes	The text to hash, up to 100 KB
`algorithm`	string	No	md5, sha1, sha256 (default), sha384 or sha512
`encoding`	string	No	hex (default) or base64

Request

curl "https://devpack.app/v1/hash?text=hello&algorithm=sha256"

Response

{
  "ok": true,
  "data": {
    "algorithm": "sha256",
    "encoding": "hex",
    "hash": "2cf24dba5fb0a30e26e83b2ac5b9e29e1b161e5c1fa7425e73043362938b9824"
  }
}

`/v1/base64`

GETPOST

Encode or decode Base64.

Parameters

Name	Type	Required	Description
`text`	string	Yes	The input, up to 100 KB
`action`	string	No	encode (default) or decode
`url_safe`	boolean	No	Use the URL-safe alphabet. Default false

Request

curl "https://devpack.app/v1/base64?text=hello+world&action=encode"

Response

{
  "ok": true,
  "data": {
    "action": "encode",
    "result": "aGVsbG8gd29ybGQ="
  }
}

`/v1/url-encode`

GETPOST

Percent-encode or decode a string.

Parameters

Name	Type	Required	Description
`text`	string	Yes	The input, up to 100 KB
`action`	string	No	encode (default) or decode

Request

curl "https://devpack.app/v1/url-encode?text=a+b%26c%3Dd&action=encode"

Response

{
  "ok": true,
  "data": {
    "action": "encode",
    "result": "a%20b%26c%3Dd"
  }
}

`/v1/slug`

GETPOST

Turn text into a URL slug.

Parameters

Name	Type	Required	Description
`text`	string	Yes	The text to convert
`separator`	string	No	- (default) or _

Request

curl "https://devpack.app/v1/slug?text=Hello%2C+W%C3%B6rld%21+It%E2%80%99s+2026"

Response

{
  "ok": true,
  "data": {
    "slug": "hello-world-its-2026"
  }
}

`/v1/text-stats`

GETPOST

Count words, characters, lines and reading time.

Parameters

Name	Type	Required	Description
`text`	string	Yes	The text, up to 100 KB

Request

curl "https://devpack.app/v1/text-stats?text=One+two+three.+Four+five%21"

Response

{
  "ok": true,
  "data": {
    "characters": 25,
    "charactersNoSpaces": 21,
    "words": 5,
    "sentences": 2,
    "lines": 1,
    "readingTimeSeconds": 2
  }
}

`/v1/json-format`

GETPOST

Validate JSON, then pretty-print or minify it.

Parameters

Name	Type	Required	Description
`json`	string	Yes	The JSON text, up to 100 KB
`indent`	integer	No	Spaces per level, 0–8. Default 2
`minify`	boolean	No	Remove all whitespace. Default false

Request

curl "https://devpack.app/v1/json-format?json=%7B%22name%22%3A%22devpack%22%2C%22tools%22%3A500%7D&indent=2"

Response

{
  "ok": true,
  "data": {
    "valid": true,
    "formatted": "{\n  \"name\": \"devpack\",\n  \"tools\": 500\n}"
  }
}

`/v1/jwt-decode`

GETPOST

Decode a JWT without verifying its signature.

Parameters

Name	Type	Required	Description
`token`	string	Yes	The JWT

Request

curl "https://devpack.app/v1/jwt-decode?token=eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjMiLCJuYW1lIjoiQWRhIiwiZXhwIjo0MTAyNDQ0ODAwfQ.c2lnbmF0dXJl"

Response

{
  "ok": true,
  "data": {
    "header": {
      "alg": "HS256",
      "typ": "JWT"
    },
    "payload": {
      "sub": "123",
      "name": "Ada",
      "exp": 4102444800
    },
    "expired": false,
    "signatureVerified": false
  }
}

`/v1/case-convert`

GETPOST

Change text case, such as camelCase or snake_case.

Parameters

Name	Type	Required	Description
`text`	string	Yes	The text, up to 100 KB
`to`	string	Yes	lower, upper, title, sentence, camel, pascal, snake, kebab or constant

Request

curl "https://devpack.app/v1/case-convert?text=Hello+big+world&to=snake"

Response

{
  "ok": true,
  "data": {
    "to": "snake",
    "result": "hello_big_world"
  }
}

`/v1/html-entities`

GETPOST

Escape or unescape HTML entities.

Parameters

Name	Type	Required	Description
`text`	string	Yes	The text, up to 100 KB
`action`	string	No	encode (default) or decode

Request

curl "https://devpack.app/v1/html-entities?text=%3Ca+href%3D%22%2F%22%3ETom+%26+Jerry%3C%2Fa%3E&action=encode"

Response

{
  "ok": true,
  "data": {
    "action": "encode",
    "result": "&lt;a href=&quot;/&quot;&gt;Tom &amp; Jerry&lt;/a&gt;"
  }
}

`/v1/csv-to-json`

GETPOST

Convert CSV to JSON.

Parameters

Name	Type	Required	Description
`csv`	string	Yes	The CSV, up to 100 KB
`delimiter`	string	No	comma (default), semicolon, tab or pipe
`header`	boolean	No	First row holds column names. Default true

Request

curl "https://devpack.app/v1/csv-to-json?csv=name%2Cage%0AAda%2C36%0AGrace%2C45"

Response

{
  "ok": true,
  "data": {
    "rows": 2,
    "columns": [
      "name",
      "age"
    ],
    "data": [
      {
        "name": "Ada",
        "age": "36"
      },
      {
        "name": "Grace",
        "age": "45"
      }
    ]
  }
}

`/v1/json-to-csv`

GETPOST

Convert a JSON array of objects to CSV.

Parameters

Name	Type	Required	Description
`json`	string	Yes	A JSON array of objects, up to 100 KB

Request

curl "https://devpack.app/v1/json-to-csv?json=%5B%7B%22name%22%3A%22Ada%22%2C%22age%22%3A36%7D%2C%7B%22name%22%3A%22Grace%22%2C%22age%22%3A45%7D%5D"

Response

{
  "ok": true,
  "data": {
    "rows": 2,
    "columns": [
      "name",
      "age"
    ],
    "csv": "name,age\nAda,36\nGrace,45"
  }
}

Generators

`/v1/uuid`

GETPOST

Generate random version 4 UUIDs.

Parameters

Name	Type	Required	Description
`count`	integer	No	1–100. Default 1

Request

curl "https://devpack.app/v1/uuid?count=2"

Response

{
  "ok": true,
  "data": {
    "uuids": [
      "cd716365-f0d5-4557-9ae6-604e40723bf8",
      "308241e6-2312-436a-83b6-4f8303fcd72e"
    ]
  }
}

`/v1/password`

GETPOST

Generate strong random passwords.

Parameters

Name	Type	Required	Description
`length`	integer	No	8–128. Default 20
`count`	integer	No	1–50. Default 1
`symbols`	boolean	No	Include symbols. Default true
`numbers`	boolean	No	Include digits. Default true
`uppercase`	boolean	No	Include capitals. Default true

Request

curl "https://devpack.app/v1/password?length=16&count=1"

Response

{
  "ok": true,
  "data": {
    "passwords": [
      "@LZ2wH47UpgY!iWK"
    ]
  }
}

`/v1/lorem-ipsum`

GETPOST

Generate placeholder text.

Parameters

Name	Type	Required	Description
`paragraphs`	integer	No	1–20. Default 1
`words`	integer	No	Words per paragraph, 5–200. Default 40

Request

curl "https://devpack.app/v1/lorem-ipsum?paragraphs=1&words=12"

Response

{
  "ok": true,
  "data": {
    "paragraphs": [
      "Lorem ipsum dolor sit amet consectetur adipiscing elit sed do eiusmod tempor."
    ]
  }
}

`/v1/random`

GETPOST

Generate secure random whole numbers.

Parameters

Name	Type	Required	Description
`min`	integer	No	Lowest value. Default 1
`max`	integer	No	Highest value. Default 100
`count`	integer	No	1–100. Default 1
`unique`	boolean	No	No repeats. Default false

Request

curl "https://devpack.app/v1/random?min=1&max=6&count=2"

Response

{
  "ok": true,
  "data": {
    "numbers": [
      2,
      5
    ]
  }
}

Conversion

`/v1/color`

GETPOST

Convert a color between hex, RGB and HSL.

Parameters

Name	Type	Required	Description
`value`	string	Yes	For example #ff6600, rgb(255, 102, 0) or hsl(24, 100%, 50%)

Request

curl "https://devpack.app/v1/color?value=%23ff6600"

Response

{
  "ok": true,
  "data": {
    "hex": "#ff6600",
    "rgb": {
      "r": 255,
      "g": 102,
      "b": 0
    },
    "hsl": {
      "h": 24,
      "s": 100,
      "l": 50
    },
    "css": {
      "rgb": "rgb(255, 102, 0)",
      "hsl": "hsl(24, 100%, 50%)"
    }
  }
}

`/v1/timestamp`

GETPOST

Convert between Unix time and ISO 8601 dates.

Parameters

Name	Type	Required	Description
`value`	string	No	Unix seconds, Unix milliseconds or an ISO date. Default: now

Request

curl "https://devpack.app/v1/timestamp?value=1798761600"

Response

{
  "ok": true,
  "data": {
    "unix": 1798761600,
    "unixMs": 1798761600000,
    "iso": "2027-01-01T00:00:00.000Z",
    "utc": "Fri, 01 Jan 2027 00:00:00 GMT"
  }
}

`/v1/url-parse`

GETPOST

Split a URL into its parts.

Parameters

Name	Type	Required	Description
`url`	string	Yes	The URL to parse

Request

curl "https://devpack.app/v1/url-parse?url=https%3A%2F%2Fdevpack.app%3A8443%2Ftools%3Fq%3Djson%26page%3D2%23top"

Response

{
  "ok": true,
  "data": {
    "protocol": "https",
    "host": "devpack.app",
    "port": "8443",
    "path": "/tools",
    "query": {
      "q": "json",
      "page": "2"
    },
    "hash": "top",
    "origin": "https://devpack.app:8443"
  }
}

`/v1/number-base`

GETPOST

Convert a whole number between bases 2 and 36.

Parameters

Name	Type	Required	Description
`value`	string	Yes	The number
`from`	integer	No	Input base. Default 10
`to`	integer	No	Output base. Default 16

Request

curl "https://devpack.app/v1/number-base?value=255&from=10&to=16"

Response

{
  "ok": true,
  "data": {
    "result": "ff",
    "decimal": "255"
  }
}

`/v1/unit-convert`

GETPOST

Convert length, weight, temperature, data and time units.

Parameters

Name	Type	Required	Description
`value`	number	Yes	The amount
`from`	string	Yes	m, km, cm, mm, in, ft, yd, mi, kg, g, mg, lb, oz, t, c, f, k, b, kb, mb, gb, tb, kib, mib, gib, ms, s, min, h, d, wk
`to`	string	Yes	The target unit, from the same type

Request

curl "https://devpack.app/v1/unit-convert?value=10&from=km&to=mi"

Response

{
  "ok": true,
  "data": {
    "value": 10,
    "from": "km",
    "to": "mi",
    "result": 6.21371192237
  }
}

`/v1/date-diff`

GETPOST

Find the time between two dates.

Parameters

Name	Type	Required	Description
`from`	string	Yes	Start date, in ISO format
`to`	string	No	End date. Default: now

Request

curl "https://devpack.app/v1/date-diff?from=2026-01-01&to=2026-10-30"

Response

{
  "ok": true,
  "data": {
    "days": 302,
    "weeks": 43.14,
    "hours": 7248,
    "minutes": 434880,
    "seconds": 26092800
  }
}

`/v1/cron-next`

GETPOST

List the next run times of a cron expression, in UTC.

Parameters

Name	Type	Required	Description
`expression`	string	Yes	Five fields: minute hour day month weekday
`count`	integer	No	1–20. Default 5
`from`	string	No	Start date. Default: now

Request

curl "https://devpack.app/v1/cron-next?expression=0+9+*+*+1&count=2&from=2026-10-30T00%3A00%3A00Z"

Response

{
  "ok": true,
  "data": {
    "expression": "0 9 * * 1",
    "runs": [
      "2026-11-02T09:00:00.000Z",
      "2026-11-09T09:00:00.000Z"
    ]
  }
}

`/v1/http-status`

GETPOST

Look up an HTTP status code.

Parameters

Name	Type	Required	Description
`code`	integer	Yes	100–599

Request

curl "https://devpack.app/v1/http-status?code=404"

Response

{
  "ok": true,
  "data": {
    "code": 404,
    "name": "Not Found",
    "class": "Client error",
    "docs": "https://devpack.app/http-status-codes/404"
  }
}

`/v1/user-agent`

GETPOST

Parse a user agent string. Defaults to the caller’s.

Parameters

Name	Type	Required	Description
`ua`	string	No	The user agent string

Request

curl "https://devpack.app/v1/user-agent?ua=Mozilla%2F5.0+%28Windows+NT+10.0%3B+Win64%3B+x64%29+AppleWebKit%2F537.36+%28KHTML%2C+like+Gecko%29+Chrome%2F130.0.0.0+Safari%2F537.36"

Response

{
  "ok": true,
  "data": {
    "userAgent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/130.0.0.0 Safari/537.36",
    "browser": {
      "name": "Chrome",
      "version": "130.0.0.0"
    },
    "os": {
      "name": "Windows",
      "version": "10.0"
    },
    "device": "desktop",
    "bot": false
  }
}

Marketing

`/v1/ab-test`

GETPOST

Check whether an A/B test result is statistically significant.

Parameters

Name	Type	Required	Description
`visitors_a`	integer	Yes	Visitors to version A
`conversions_a`	integer	Yes	Conversions for version A
`visitors_b`	integer	Yes	Visitors to version B
`conversions_b`	integer	Yes	Conversions for version B
`confidence`	integer	No	90, 95 (default) or 99

Request

curl "https://devpack.app/v1/ab-test?visitors_a=1000&conversions_a=100&visitors_b=1000&conversions_b=130"

Response

{
  "ok": true,
  "data": {
    "rateA": 0.1,
    "rateB": 0.13,
    "uplift": 0.3,
    "zScore": 2.1027,
    "pValue": 0.035488,
    "confidence": 95,
    "significant": true,
    "winner": "B"
  }
}

Network

`/v1/ip`

GETPOST

Return the IP address of the caller.

Request

curl "https://devpack.app/v1/ip"

Response

{
  "ok": true,
  "data": {
    "ip": "203.0.113.42",
    "version": "IPv4"
  }
}

`/v1/dns`

GETPOST

Look up DNS records. Network check

Parameters

Name	Type	Required	Description
`domain`	string	Yes	The domain or IPv4 address
`types`	string	No	Comma-separated: A, AAAA, CNAME, MX, TXT, NS, SOA, CAA, SRV, PTR. Default: the common set

Request

curl "https://devpack.app/v1/dns?domain=example.com&types=A%2CMX"

Response

{
  "ok": true,
  "data": {
    "domain": "example.com",
    "results": [
      {
        "type": "A",
        "status": 0,
        "records": [
          {
            "name": "example.com",
            "ttl": 300,
            "type": "A",
            "data": "93.184.215.14"
          }
        ]
      },
      {
        "type": "MX",
        "status": 0,
        "records": [
          {
            "name": "example.com",
            "ttl": 3600,
            "type": "MX",
            "data": "0 mail.example.com."
          }
        ]
      }
    ],
    "resolver": "Cloudflare 1.1.1.1 (DNS over HTTPS)"
  }
}

`/v1/ssl`

GETPOST

Check a site’s SSL certificate. Network check

Parameters

Name	Type	Required	Description
`domain`	string	Yes	The host name

Request

curl "https://devpack.app/v1/ssl?domain=example.com"

Response

{
  "ok": true,
  "data": {
    "host": "example.com",
    "valid": true,
    "protocol": "TLSv1.3",
    "daysLeft": 74,
    "hostnameMatches": true,
    "sans": [
      "example.com",
      "www.example.com"
    ],
    "issuer": {
      "C": "US",
      "O": "Example CA",
      "CN": "Example CA R1"
    },
    "validFrom": "Oct 1 00:00:00 2026 GMT",
    "validTo": "Jan 12 23:59:59 2027 GMT"
  }
}

`/v1/status`

GETPOST

Check whether a website is up. Network check

Parameters

Name	Type	Required	Description
`url`	string	Yes	The page to check

Request

curl "https://devpack.app/v1/status?url=https%3A%2F%2Fexample.com"

Response

{
  "ok": true,
  "data": {
    "url": "https://example.com/",
    "finalUrl": "https://example.com/",
    "up": true,
    "status": 200,
    "time": 182,
    "ttfb": 96,
    "title": "Example Domain",
    "server": "cloudflare",
    "checkedAt": "2026-10-30T12:00:00.000Z"
  }
}

`/v1/headers`

GETPOST

Read HTTP headers and grade security headers. Network check

Parameters

Name	Type	Required	Description
`url`	string	Yes	The page to check

Request

curl "https://devpack.app/v1/headers?url=https%3A%2F%2Fexample.com"

Response

{
  "ok": true,
  "data": {
    "url": "https://example.com/",
    "status": 200,
    "headers": {
      "content-type": "text/html",
      "server": "cloudflare"
    },
    "security": {
      "score": 25,
      "grade": "E",
      "https": true,
      "missing": [
        "Content-Security-Policy",
        "X-Frame-Options"
      ]
    }
  }
}

`/v1/redirects`

GETPOST

Follow a URL’s redirect chain. Network check

Parameters

Name	Type	Required	Description
`url`	string	Yes	The URL to follow

Request

curl "https://devpack.app/v1/redirects?url=http%3A%2F%2Fexample.com"

Response

{
  "ok": true,
  "data": {
    "requested": "http://example.com/",
    "final": "https://example.com/",
    "status": 200,
    "chain": [
      {
        "url": "http://example.com/",
        "status": 301,
        "time": 88
      },
      {
        "url": "https://example.com/",
        "status": 200,
        "time": 126
      }
    ],
    "totalTime": 214
  }
}

`/v1/whois`

GETPOST

Look up domain or IP registration data (RDAP). Network check

Parameters

Name	Type	Required	Description
`query`	string	Yes	The domain or IP address

Request

curl "https://devpack.app/v1/whois?query=example.com"

Response

{
  "ok": true,
  "data": {
    "kind": "domain",
    "query": "example.com",
    "domain": "EXAMPLE.COM",
    "source": "https://rdap.verisign.com/com/v1/domain/example.com",
    "status": [
      "client delete prohibited"
    ],
    "registrar": "Example Registrar",
    "ianaId": "376",
    "created": "1995-08-14T04:00:00Z",
    "updated": "2026-08-14T08:01:43Z",
    "expires": "2027-08-13T04:00:00Z",
    "dnssec": true,
    "nameservers": [
      "ns1.example.net",
      "ns2.example.net"
    ],
    "entities": []
  }
}

`/v1/meta`

GETPOST

Read a page’s title, description and social tags. Network check

Parameters

Name	Type	Required	Description
`url`	string	Yes	The page to read

Request

curl "https://devpack.app/v1/meta?url=https%3A%2F%2Fexample.com"

Response

{
  "ok": true,
  "data": {
    "url": "https://example.com/",
    "status": 200,
    "title": "Example Domain",
    "description": "An example page.",
    "canonical": "https://example.com/",
    "robots": null,
    "openGraph": {
      "title": "Example Domain",
      "description": "An example page.",
      "image": "https://example.com/og.png"
    },
    "twitter": {
      "card": "summary_large_image",
      "image": "https://example.com/og.png"
    }
  }
}

`/v1/robots`

GETPOST

Read a site’s robots.txt and test whether a path is allowed. Network check

Parameters

Name	Type	Required	Description
`url`	string	Yes	The page or site
`user_agent`	string	No	Crawler to test. Default Googlebot

Request

curl "https://devpack.app/v1/robots?url=https%3A%2F%2Fexample.com%2F&user_agent=Googlebot"

Response

{
  "ok": true,
  "data": {
    "exists": true,
    "test": {
      "path": "/",
      "ua": "Googlebot",
      "allowed": true,
      "rule": null,
      "group": "*"
    },
    "bots": [
      {
        "bot": "Googlebot",
        "allowed": true,
        "rule": null,
        "group": "*"
      },
      {
        "bot": "GPTBot",
        "allowed": false,
        "rule": "/",
        "group": "gptbot"
      }
    ]
  }
}

`/v1/email-dns`

GETPOST

Check a domain’s MX, SPF and DMARC email setup. Network check

Parameters

Name	Type	Required	Description
`domain`	string	Yes	The domain

Request

curl "https://devpack.app/v1/email-dns?domain=example.com"

Response

{
  "ok": true,
  "data": {
    "domain": "example.com",
    "checks": [
      {
        "id": "spf",
        "status": "ok",
        "title": "SPF valid · 0/10 lookups · -all",
        "detail": "v=spf1 -all"
      },
      {
        "id": "dmarc",
        "status": "ok",
        "title": "DMARC enforced · p=reject",
        "detail": "v=DMARC1;p=reject"
      }
    ]
  }
}

`/v1/tech`

GETPOST

Detect the technologies a website uses. Network check

Parameters

Name	Type	Required	Description
`url`	string	Yes	The site to check

Request

curl "https://devpack.app/v1/tech?url=https%3A%2F%2Fexample.com"

Response

{
  "ok": true,
  "data": {}
}