Developer API

QRMaster API Reference

Generate QR codes programmatically from any language. One endpoint, simple JSON, returns PNG or base64.

Base URL: qrmaster.appPro plan required100 requests / day

Authentication

All requests must include your API key in the x-api-key header. Generate your key from the QRMaster dashboard (Pro plan required).

x-api-key: qrm_your_api_key

Keep your API key secret. Do not expose it in client-side code or public repositories.

Endpoint

POST/api/generate

Accepts a JSON body, validates your key, applies rate limits, and returns a QR code as base64 JSON or a raw PNG.

Request Parameters

Parameter	Type	Required	Description
url	string	Yes	The URL or text to encode in the QR code.
color	string	No	Foreground hex color. Default: "#000000"
background	string	No	Background hex color. Default: "#ffffff"
size	number	No	Output size in pixels (100–1000). Default: 300
format	string	No	"base64" (default) or "png" to get raw image bytes.

Response

Base64 Response (default)

{
  "success": true,
  "data": "iVBORw0KGgoAAAANSUhEUgAA...",
  "format": "base64",
  "size": 300
}

Decode data with base64.decode() or use it directly as data:image/png;base64,{data} in an <img> src.

PNG Response (format: "png")

HTTP/1.1 200 OK
Content-Type: image/png
X-RateLimit-Limit: 100
X-RateLimit-Remaining: 87

[binary PNG data]

Rate Limits

Each API key is limited to 100 requests per day. The limit resets at midnight UTC. Every response includes rate limit headers.

X-RateLimit-Limit: 100
X-RateLimit-Remaining: 87

When the limit is exceeded, the API returns 429 Too Many Requests with a descriptive error message.

Error Codes

Status	Meaning
400	Bad request — missing or invalid parameters
401	Unauthorized — missing or invalid API key
422	Unprocessable — QR generation failed (e.g. invalid URL)
429	Too many requests — daily rate limit exceeded
500	Internal server error

Error response shape

{ "error": "Human-readable error message." }

Code Examples

cURL — base64 response

curl -X POST https://qrmaster.app/api/generate \
  -H "x-api-key: qrm_your_api_key" \
  -H "Content-Type: application/json" \
  -d '{
    "url": "https://example.com",
    "color": "#0B0D12",
    "background": "#ffffff",
    "size": 400,
    "format": "base64"
  }'

cURL — download PNG directly

curl -X POST https://qrmaster.app/api/generate \
  -H "x-api-key: qrm_your_api_key" \
  -H "Content-Type: application/json" \
  -d '{"url":"https://example.com","format":"png"}' \
  --output qr.png

JavaScript / TypeScript

const response = await fetch("https://qrmaster.app/api/generate", {
  method: "POST",
  headers: {
    "x-api-key": "qrm_your_api_key",
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    url: "https://example.com",
    color: "#0B0D12",
    background: "#ffffff",
    size: 400,
    format: "base64",
  }),
});

const { data } = await response.json();
// data is a base64-encoded PNG string
const img = document.createElement("img");
img.src = `data:image/png;base64,${data}`;

Python

import requests, base64

response = requests.post(
    "https://qrmaster.app/api/generate",
    headers={"x-api-key": "qrm_your_api_key"},
    json={
        "url": "https://example.com",
        "color": "#0B0D12",
        "background": "#ffffff",
        "size": 400,
        "format": "base64",
    },
)

payload = response.json()
img_bytes = base64.b64decode(payload["data"])
with open("qr.png", "wb") as f:
    f.write(img_bytes)

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