A powerful and customizable captcha generator for Node.js, powered by skia-canvas.
- Highly Customizable: Control every aspect of the captcha, including text, fonts, colors, backgrounds, and more.
- Secure: Generates complex captchas that are difficult for OCR bots to solve.
- Flexible: Use the simple
createCaptchafor quick generation or theCaptchaGeneratorclass for more advanced use cases. - Background Support: Add custom background images to your captchas.
- Lightweight: No bundled dependencies, keeping your project lean.
Before installing captcha-canvas, you need to install its peer dependency, skia-canvas.
npm install skia-canvas
npm install captcha-canvasThe easiest way to generate a captcha is with the createCaptcha function.
const fs = require("fs");
const { createCaptchaSync } = require("captcha-canvas");
const { image, text } = createCaptchaSync(100, 300);
fs.writeFileSync("captcha.png", image);
console.log("Captcha text:", text);This will generate a file named captcha.png with a random captcha image.
For more control over the captcha generation process, use the CaptchaGenerator class.
const fs = require("fs");
const { CaptchaGenerator } = require("captcha-canvas");
const captcha = new CaptchaGenerator()
.setDimension(150, 450)
.setCaptcha({ font: "Comic Sans", size: 60, color: "deeppink" })
.setTrace({ color: "deeppink" })
.setDecoy({ color: "deeppink" });
const buffer = captcha.generateSync();
fs.writeFileSync("captcha.png", buffer);
console.log("Captcha text:", captcha.text);You can customize the captcha text, trace lines, and decoy characters.
captcha.setDimension(200, 600); // height, widthcaptcha.setBackground("./path/to/background.png");captcha.setCaptcha({
text: "MyCustomText",
color: "#2D3748",
font: "Arial",
size: 70,
skew: true,
rotate: 10, // rotation angle in degrees
opacity: 0.8
});The trace line is drawn over the captcha text.
captcha.setTrace({
color: "#2D3748",
size: 5,
opacity: 0.7
});Decoy characters are random characters added to the background to make the captcha harder to read for bots.
captcha.setDecoy({
color: "#A0AEC0",
font: "Arial",
size: 40,
opacity: 0.5,
total: 25 // number of decoy characters
});If you are using a background image, you should use the asynchronous generate() method.
const buffer = await captcha.generate();
fs.writeFileSync("captcha.png", buffer);For a full list of options and methods, please see the API documentation.
Contributions are welcome! Please open an issue to report bugs or suggest features.
This project is licensed under the Apache-2.0 License. See the LICENSE file for details.
Thanks goes to these wonderful people (emoji key):
Shashank 📆 |
TheDeadCraftPT 🐛 |
IchiiDev 🐛 |
Ikramullah 📖 💻 |
ryanhex53 💻 |
This project follows the all-contributors specification. Contributions of any kind welcome!