captcha.Captchaer comes with a variety of configuration options:
// ...m.Use(captcha.Captchaer(captcha.Options{// URL prefix of getting captcha pictures. Default is "/captcha/". URLPrefix: "/captcha/",// Hidden input element ID. Default is "captcha_id". FieldIdName: "captcha_id",// User input value element name in request form. Default is "captcha". FieldCaptchaName: "captcha",// Challenge number. Default is 6. ChallengeNums: 6,// Captcha image width. Default is 240. Width: 240,// Captcha image height. Default is 80. Height: 80,// Captcha expiration time in seconds. Default is 600. Expiration: 600,// Cache key prefix captcha characters. Default is "captcha_". CachePrefix: "captcha_",}))// ...