Fast developer utilities. No signup. No tracking.

Developer Tools, Instantly

JSON formatter, Base64, hashing, JWT decoder, UUID generator, timestamps — all in one place, all client-side, all free.

Now at apitoolkit.pro

{ }

JSON Formatter

Pretty-print, validate, and minify JSON

Ab

Base64 Encode/Decode

Convert text to and from Base64

#

Hash Generator

SHA-256, SHA-512, MD5 hashing

🔑

JWT Decoder

Decode and inspect JWT tokens

ID

UUID Generator

Generate random v4 UUIDs

⏱

Timestamp Converter

Unix timestamps to ISO and back

.*

Regex Tester

Test patterns, highlight matches

±

Diff Viewer

Compare two blocks of text

%20

URL Encoder/Decoder

Encode and decode URL components

⏰

Cron Parser

Show next run times for a cron expression

JSON Formatter

Base64 Encode/Decode

Hash Generator

JWT Decoder

UUID Generator

Timestamp Converter

Regex Tester

Diff Viewer

URL Encoder/Decoder

Cron Expression Parser

API Toolkit Pro — Developer API

Use these tools programmatically. Unlimited requests, no rate limits. API key delivered instantly after checkout.

$5/month

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API Reference

Web tools are always free. For programmatic access, use /api/v1/* with your X-Api-Key header (requires subscription).

# Verify your API key
curl https://apitoolkit.pro/api/verify-key \
  -H "X-Api-Key: atpro_..."

# Format JSON (paid API)
curl -X POST https://apitoolkit.pro/api/v1/format-json \
  -H "X-Api-Key: atpro_..." \
  -H "Content-Type: application/json" \
  -d '{"key":"value"}'

# Base64 / Hash / JWT / UUID / Timestamp / Regex / Diff / URL-encode / Cron
curl -X POST https://apitoolkit.pro/api/v1/base64    -H "X-Api-Key: atpro_..." -d '{"action":"encode","input":"hello"}'
curl -X POST https://apitoolkit.pro/api/v1/hash      -H "X-Api-Key: atpro_..." -d '{"input":"hello","algorithm":"sha256"}'
curl -X POST https://apitoolkit.pro/api/v1/jwt-decode -H "X-Api-Key: atpro_..." -d '{"token":"eyJ..."}'
curl -X POST https://apitoolkit.pro/api/v1/uuid      -H "X-Api-Key: atpro_..."
curl -X POST https://apitoolkit.pro/api/v1/timestamp -H "X-Api-Key: atpro_..." -d '{"action":"to_iso","input":"1712345678"}'
curl -X POST https://apitoolkit.pro/api/v1/regex     -H "X-Api-Key: atpro_..." -d '{"pattern":"\\w+","flags":"g","input":"hello world"}'
curl -X POST https://apitoolkit.pro/api/v1/diff      -H "X-Api-Key: atpro_..." -d '{"a":"line1\nline2","b":"line1\nline3"}'
curl -X POST https://apitoolkit.pro/api/v1/url-encode -H "X-Api-Key: atpro_..." -d '{"action":"encode","input":"hello world"}'
curl -X POST https://apitoolkit.pro/api/v1/cron      -H "X-Api-Key: atpro_..." -d '{"expression":"*/5 * * * *","count":5}'