Free REST APIs for developers. No signup, no API keys, no rate limits.
All endpoints accept POST requests with JSON body. Base URL: https://emptychair.dev
Transform text: uppercase, lowercase, titlecase, slug, reverse, count
curl -X POST https://emptychair.dev/api/text-transform \
-H "Content-Type: application/json" \
-d '{"text": "Hello World", "operation": "slug"}'
# Response: {"result": "hello-world"}
Operations: uppercase, lowercase, titlecase, slug, reverse, count
Validate, format, or minify JSON
curl -X POST https://emptychair.dev/api/json-utils \
-H "Content-Type: application/json" \
-d '{"json": "{\"test\": 123}", "operation": "format"}'
# Response: {"result": "{\n \"test\": 123\n}"}
Operations: validate, format, minify
Base64, URL encoding, MD5, SHA256 hashing
curl -X POST https://emptychair.dev/api/hash-encode \
-H "Content-Type: application/json" \
-d '{"data": "Hello World", "operation": "base64-encode"}'
# Response: {"result": "SGVsbG8gV29ybGQ="}
Operations: base64-encode, base64-decode, url-encode, url-decode, md5, sha256
Generate UUIDs, random strings, numbers
curl -X POST https://emptychair.dev/api/random \
-H "Content-Type: application/json" \
-d '{"type": "uuid"}'
# Response: {"result": "550e8400-e29b-41d4-a716-446655440000"}
Types: uuid, string, number, password
Timestamp conversion and formatting
curl -X POST https://emptychair.dev/api/time \
-H "Content-Type: application/json" \
-d '{"operation": "now"}'
# Response: {"iso": "2024-...", "unix": 1704..., "human": "..."}
Operations: now, parse, format, diff
Convert Markdown to HTML
curl -X POST https://emptychair.dev/api/markdown \
-H "Content-Type: application/json" \
-d '{"markdown": "# Hello\n\nThis is **bold**"}'
# Response: {"result": "<h1>Hello</h1>..."}
Generate placeholder text
curl -X POST https://emptychair.dev/api/lorem \
-H "Content-Type: application/json" \
-d '{"count": 2, "type": "paragraphs"}'
# Response: {"result": "Lorem ipsum dolor..."}
Types: words, sentences, paragraphs
Convert between HEX, RGB, HSL
curl -X POST https://emptychair.dev/api/color \
-H "Content-Type: application/json" \
-d '{"color": "ff5500", "from": "hex", "to": "rgb"}'
# Response: {"result": "rgb(255, 85, 0)"}
Formats: hex, rgb, hsl
Test regular expressions
curl -X POST https://emptychair.dev/api/regex \
-H "Content-Type: application/json" \
-d '{"pattern": "[a-z]+", "text": "hello123world", "flags": "g"}'
# Response: {"result": {"matches": ["hello", "world"], "matchCount": 2}}
Generate QR codes as SVG, PNG, or ASCII
curl -X POST https://emptychair.dev/api/qrcode \
-H "Content-Type: application/json" \
-d '{"data": "https://emptychair.dev", "format": "svg"}'
# Response: {"result": "<svg...>"} (or ASCII art for text format)
Formats: svg, base64, text