QR Code API

The ChartQuery QR Code API generates styled QR codes — dot styles, colors, gradients, custom corners and all QR versions — as SVG (default) or PNG.

• QR Code API — Generate a styled QR code via GET.

Use it for tickets, packaging, marketing campaigns, payments, Wi-Fi access and vCards.

Endpoint	Request	Credits
QR Code API	GET /v1/qrcode	3

Table of contents

• How it works
• QR Code API
• Code examples in other languages
• Use cases
• Why ChartQuery?
• FAQ
• Related repositories
• Support

How it works

1. Create a ChartQuery account and copy your API key from the dashboard.
2. Call https://api.chartquery.com with the header x-api-key: YOUR_API_KEY.
3. Use the result in your app — no infrastructure to run.

export CHARTQUERY_API_KEY="your-api-key"
pip install requests        # Python
# TypeScript: Node.js 18+ (native fetch), run with `npx tsx file.ts`

QR Code API

Generate a styled QR code via GET. Output: SVG (default) or PNG. Supports dot styles, gradients, custom corners and all QR versions.

GET https://api.chartquery.com/v1/qrcode · 3 credits per request · API reference

Request parameters

Parameter	In	Type	Required	Description
data	query	string	✅	Data to encode in the QR code. Examples:
size	query	number	—	Output size in pixels (width = height). Default: 200. Examples: ?size=200 (thumbnail), ?size=300 (standard), ?size=400 (large), ?size=600 (poster). For print, use the unit param with mm/cm instead.
ec_level	query	string (L, M, Q, H)	—	Error correction level. Default: M. Higher levels allow more damage/obscuring before the code becomes unreadable.
dot_type	query	string (square, rounded, dots, diamond, classy, classy-rounded)	—	Module (dot) shape. Default: square. Controls the visual style of each QR code module.
color	query	string	—	Module color as CSS hex. Default: #000. Examples: ?color=%236366f1 (indigo), ?color=%23dc2626 (red), ?color=%23059669 (green), ?color=%230891b2 (teal). Use %23 to URL-encode #. For gradient objects, use POST instead.
shape	query	string (square, circle)	—	Overall QR code shape. Default: square. Use circle to clip the entire QR into a circle: great for profile/avatar-style codes. Example: ?shape=circle&dot_type=dots
dot_size	query	number	—	Module size ratio between 0.1 and 1. Default: 1 (full). Values below 1 add spacing between modules for a lighter look. Example: ?dot_size=0.85
background	query	string	—	Background color. Default: #fff. Set to transparent for no background. Example: ?background=%230f172a for dark background. Use %23 to encode #.
margin	query	number	—	Quiet zone width in modules around the QR code. Default: 4. Minimum recommended by the QR standard: 4. Example: ?margin=2 (compact) or ?margin=6 (extra padding).
version	query	number	—	QR version from 1 to 40 (determines grid size and data capacity). Leave unset for auto-selection based on data length and ec_level. Example: ?version=5
mode	query	string (auto, numeric, alphanumeric, byte)	—	Encoding mode. Default: auto (best mode selected for the data). Use numeric for digits-only, alphanumeric for uppercase + digits, byte for arbitrary text/UTF-8. Example: ?mode=numeric
mask	query	number	—	Mask pattern from 0 to 7. Default: auto (best mask selected to minimize visual patterns). Only set manually if you need a deterministic output. Example: ?mask=3
unit	query	string (px, mm, in, cm)	—	Measurement unit for the size param. Default: px. Use mm, in or cm with the size param for print-ready output. Example: ?size=50&unit=mm
xml_declaration	query	boolean	—	Prepend an XML declaration () to the SVG output. Useful when the SVG will be used as a standalone XML file. Default: false. Example: ?xml_declaration=true
aria_label	query	string	—	Accessible label added as aria-label on the SVG element. Example: ?aria_label=QR+code+linking+to+chartquery.com
title	query	string	—	SVG <title> element shown as a browser tooltip and used by screen readers. Example: ?title=ChartQuery+Website
desc	query	string	—	SVG element for extended accessibility description. Example: ?desc=Scan+to+visit+https://chartquery.com
format	query	string (svg, png)	—	Output format. Default: svg. Use png to get a raster image. SVG is lossless and scalable; PNG is pixel-based and suitable for email, PDF or messaging. Example: ?format=png
share	query	boolean (false, true)	—	Set share=true to persist the config and receive JSON instead of an image: { id, render_url, view_url, embed_url, expires_in }. Free plan: 3-day expiry with watermark. Paid plan: 6-month expiry, no branding.

Python example

import os

import requests

API_KEY = os.environ["CHARTQUERY_API_KEY"]
HEADERS = {"x-api-key": API_KEY}

response = requests.get(
    "https://api.chartquery.com/v1/qrcode",
    headers=HEADERS,
    params={
        "data": "https://chartquery.com",
        "format": "png",
    },
    timeout=120,
)
response.raise_for_status()

with open("qrcode.png", "wb") as f:
    f.write(response.content)
print("Saved qrcode.png", len(response.content), "bytes")

TypeScript example

import { writeFile } from "node:fs/promises";

const headers = { "x-api-key": process.env.CHARTQUERY_API_KEY!, "Content-Type": "application/json" };

const params = new URLSearchParams({
  "data": "https://chartquery.com",
  "format": "png",
});

const response = await fetch(`https://api.chartquery.com/v1/qrcode?${params}`, { headers });
if (!response.ok) throw new Error(`HTTP ${response.status}: ${await response.text()}`);

await writeFile("qrcode.png", Buffer.from(await response.arrayBuffer()));
console.log("Saved qrcode.png");

Output

The response body is the generated file (saved as qrcode.png in every example). Error responses are JSON with an explanatory message.

Code examples in other languages

Ready-to-run examples live in examples/; each reads your key from CHARTQUERY_API_KEY.

Language	qrcode
cURL (Bash)	qrcode.sh
PHP	qrcode.php
C#	Qrcode.cs
Go	qrcode.go
Java	QrcodeExample.java
Ruby	qrcode.rb
Node.js	qrcode.mjs

Use cases

• Marketing — Branded QR codes for print and packaging.
• Tickets & events — Generate unique QR codes per attendee.
• Wi-Fi & contacts — Encode Wi-Fi credentials, vCards, emails or SMS.

Why ChartQuery?

• Images in one request — the response body is the PNG/SVG/PDF, ready for emails, PDFs, dashboards, Slack or <img> tags.
• Charts, diagrams, QR codes, barcodes, labels — Chart.js configs, 28 diagram languages (Mermaid, Graphviz, PlantUML, D2…), 25+ barcode formats.
• AI generation — describe a chart or diagram in plain English and get the rendered image.
• No rendering infrastructure — no headless browser, fonts or libraries to maintain.
• Copy-paste examples — Python and TypeScript in each README, 7 more languages in examples/.

FAQ

How do I authenticate?

Create an account on ChartQuery, copy your API key and send it in the x-api-key header of every request to https://api.chartquery.com.

How much does a request cost?

Credits per call: /v1/qrcode 3. See ChartQuery pricing.

What does the API return?

The response body is the file itself (image or document). Save it directly to disk or stream it to your storage — every example in this repository writes the file locally.

Which languages are supported?

Any language that can make an HTTP request. This README shows Python and TypeScript; the examples/ folder contains cURL, PHP, C#, Go, Java, Ruby and Node.js.

Related repositories

• Chart API
• Diagram API
• Barcode API
• Thermal Label API
• All ChartQuery repositories

Support

• 💬 Join the Discord to ask questions and share what you build.
• 📚 Read the API reference.
• 🔑 Get your API key.

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_{Built by ChartQuery. Examples are released under the MIT license.}