JSON, CSV, YAML, Base64, Hash

All in one API. Format, validate, convert, and hash data via simple REST endpoints. Free and unlimited.

# Format JSON
curl -X POST https://fmtapi.celpippractice.workers.dev/v1/json/format \
  -H "Content-Type: application/json" \
  -d '{"data":"{\"a\":1,\"b\":2}"}'

What You Can Do

Format & Beautify

Pretty-print JSON, XML, SQL. Choose indent style and width.

Validate

Check if JSON, YAML, or CSV is valid. Get detailed error messages.

Convert

JSON to CSV, CSV to JSON, YAML to JSON, Base64 encode/decode.

Hash & Encode

MD5, SHA-256, SHA-512, HMAC. URL encode/decode. UUID generation.

Pricing

FREE

Unlimited requests. No API key needed. No rate limits.

API Reference

POST /v1/json/format

Pretty-print a JSON string.

FieldTypeDescription
datastringJSON string to format (required)
indentintSpaces for indentation (default 2)
curl -X POST https://fmtapi.celpippractice.workers.dev/v1/json/format \
  -d '{"data":"{\"name\":\"test\",\"val\":42}","indent":4}'

POST /v1/json/validate

Check if a string is valid JSON. Returns valid: true/false and error details.

curl -X POST https://fmtapi.celpippractice.workers.dev/v1/json/validate \
  -d '{"data":"{bad json}"}'

POST /v1/csv/to-json

Convert CSV data to a JSON array of objects.

curl -X POST https://fmtapi.celpippractice.workers.dev/v1/csv/to-json \
  -d '{"data":"name,age\nAlice,30\nBob,25"}'

POST /v1/json/to-csv

Convert a JSON array of objects to CSV.

curl -X POST https://fmtapi.celpippractice.workers.dev/v1/json/to-csv \
  -d '{"data":"[{\"name\":\"Alice\",\"age\":30}]"}'

POST /v1/yaml/to-json

Parse YAML and return JSON.

curl -X POST https://fmtapi.celpippractice.workers.dev/v1/yaml/to-json \
  -d '{"data":"name: test\nvalue: 42"}'

POST /v1/base64/encode

Base64-encode a string.

curl -X POST https://fmtapi.celpippractice.workers.dev/v1/base64/encode \
  -d '{"data":"Hello, World!"}'

POST /v1/base64/decode

Decode a Base64 string back to plain text.

POST /v1/hash

Generate a hash of the input data.

FieldTypeDescription
datastringInput string (required)
algostringmd5, sha256, sha512 (default sha256)
curl -X POST https://fmtapi.celpippractice.workers.dev/v1/hash \
  -d '{"data":"hello","algo":"sha256"}'

GET /v1/uuid

Generate a random UUID v4.

curl https://fmtapi.celpippractice.workers.dev/v1/uuid

POST /v1/url/encode & /v1/url/decode

URL-encode or decode a string.