svg-captcha

svg captcha

generate svg captcha in node.js

Translations

中文

useful if you

• cannot or do not want to use google recaptcha
• have issue with install c++ addon

install

npm install --save svg-captcha

usage

var svgCaptcha = require('svg-captcha');

var captcha = svgCaptcha.create();
console.log(c);
// {data: '<svg.../svg>', text: 'abcd'}

with express

var svgCaptcha = require('svg-captcha');

app.get('/captcha', function (req, res) {
	var captcha = svgCaptcha.create();
	req.session.captcha = captcha.text;
	
	res.set('Content-Type', 'image/svg+xml');
	res.status(200).send(captcha.data);
});

API

svgCaptcha.create(options)
If no option is passed, you will get a random string of four characters and corresponding svg.

options: object
{
  size: 4 // size of random string
  ignoreChars: '0o1i' // filter out some characters like 0o1i
  noise: 1 // number of noise lines
  color: true // characters will have distinct colors instead of grey, true if background option is set
  background: '#cc9966' // background color of the svg image
}

The previous options will be passed to the following functions svgCaptcha.randomText([size|options])
svgCaptcha(text, options) In pre 1.1.0 version you have to call these two functions,
now you can call create() to save some key strokes ;).

sample image

why use svg?

It does not require any c++ addon.
The result image is smaller than jpeg image.

This has to be a joke. /<text.+>;.+</text>/g.test...

svg captcha uses opentype.js underneath, which means that there is no '<text>1234</text>'.
You get '<path fill="#444" d="M104.83 19.74L107.85 19.74L112 33.56L116.13 19.74L119.15 19.74L113.48 36.85...'
instead.

Even though you can write a program that convert svg to png, svg captcha has done its job
—— make captcha recognition harder

License

MIT