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Free public API

FreeToolz Developer API

Use our utilities directly from your app, scripts, or workflows. One endpoint, JSON in, JSON out. No billing, no quotas to upgrade — just a free API key tied to your account.

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API keys

Generate or revoke keys anytime from your account page.

One endpoint

POST to /api/public/v1/run with a tool slug and input object.

Free forever

No billing, no paywalls. Fair-use applies on shared infrastructure.

Quick start

  1. Sign in and open your account.
  2. Create an API key — copy the secret. It is shown once.
  3. Make a POST request with the Authorization: Bearer … header.
cURL
curl -X POST https://freetoolz.app/api/public/v1/run \
  -H "Authorization: Bearer ftz_yourapikeyhere" \
  -H "Content-Type: application/json" \
  -d '{"tool":"slugify","input":{"text":"Hello, World!"}}'
JavaScript / fetch
const res = await fetch("https://freetoolz.app/api/public/v1/run", {
  method: "POST",
  headers: {
    "Authorization": "Bearer ftz_yourapikeyhere",
    "Content-Type": "application/json",
  },
  body: JSON.stringify({ tool: "hash", input: { text: "hello", algorithm: "sha256" } }),
});
const { result } = await res.json();
console.log(result.hash);

Endpoint

POST
https://freetoolz.app/api/public/v1/run

Body: { "tool": "<slug>", "input": { ... } }. Response: { "tool": "<slug>", "result": { ... } } or { "error": "<message>" }.

Available tools

Slugify

Convert any string into a URL-friendly slug.

slugify
Example input
{
  "text": "Hello, World!"
}
Fields: text — Source string

Word & character count

Count words, characters, sentences, and reading time.

word-count
Example input
{
  "text": "The quick brown fox jumps over the lazy dog."
}
Fields: text — Source text

Reverse text

Reverse the order of characters in a string.

reverse-text
Example input
{
  "text": "freetoolz"
}
Fields: text — Source string

Base64 encode

Encode a UTF-8 string to standard Base64.

base64-encode
Example input
{
  "text": "hello"
}
Fields: text — Source string

Base64 decode

Decode a Base64 string back to UTF-8.

base64-decode
Example input
{
  "text": "aGVsbG8="
}
Fields: text — Base64 string

URL encode

Percent-encode a string for safe use in URLs.

url-encode
Example input
{
  "text": "hello world & friends"
}
Fields: text — Source string

URL decode

Decode a percent-encoded URL string.

url-decode
Example input
{
  "text": "hello%20world"
}
Fields: text — Encoded string

Hash generator

Hash a string with md5, sha1, sha256, or sha512.

hash
Example input
{
  "text": "hello",
  "algorithm": "sha256"
}
Fields: text — Source stringalgorithm — md5 | sha1 | sha256 | sha512

UUID generator

Generate one or more v4 UUIDs.

uuid
Example input
{
  "count": 3
}
Fields: count — How many to generate (1-100)

Lorem ipsum

Generate placeholder text by word count.

lorem-ipsum
Example input
{
  "words": 25
}
Fields: words — Number of words (1-1000)

JSON format

Validate and pretty-print a JSON string.

json-format
Example input
{
  "text": "{\"a\":1,\"b\":[1,2]}",
  "indent": 2
}
Fields: text — JSON stringindent — Indent spaces (0-8, default 2)

Fair use

The API is free and shared. Please be a good neighbour: keep request volume reasonable, cache results when you can, and don't ship API keys in client-side bundles. Abusive keys may be revoked without notice.