diff --git a/CONTRIBUTORS.md b/CONTRIBUTORS.md
index e10ca14d4c..1ab702c85b 100644
--- a/CONTRIBUTORS.md
+++ b/CONTRIBUTORS.md
@@ -423,6 +423,7 @@ All definitions files include a header with the author and editors, so at some p
 * [urlrouter](https://github.com/fengmk2/urlrouter) (by [Carlos Ballesteros Velasco](https://github.com/soywiz))
 * [UUID.js](https://github.com/LiosK/UUID.js) (by [Jason Jarrett](https://github.com/staxmanade))
 * [Valerie](https://github.com/davewatts/valerie) (by [Howard Richards](https://github.com/conficient))
+* [validator](https://github.com/chriso/validator.js) (by [tgfjt](https://github.com/tgfjt))
 * [Velocity](http://velocityjs.org/) (by [Greg Smith](https://github.com/smrq))
 * [Viewporter](https://github.com/zynga/viewporter) (by [Boris Yankov](https://github.com/borisyankov))
 * [Vimeo](http://developer.vimeo.com/player/js-api) (by [Daz Wilkin](https://github.com/DazWilkin/))
diff --git a/validator/validator-tests.ts b/validator/validator-tests.ts
new file mode 100644
index 0000000000..b7f45d4271
--- /dev/null
+++ b/validator/validator-tests.ts
@@ -0,0 +1,106 @@
+/// <reference path="./validator.d.ts" />
+
+import validator = require("validator");
+
+
+validator.extend("isTest", function(str) {
+  return !str;
+});
+
+validator.equals("abc", "Abc");
+
+validator.contains("foo", "foobar");
+
+validator.matches("foobar", "foo/i");
+
+validator.isEmail("sample");
+
+validator.isURL("sample");
+
+validator.isFQDN("sample");
+
+validator.isIP("sample");
+
+validator.isAlpha("sample");
+
+validator.isNumeric("sample");
+
+validator.isAlphanumeric("sample");
+
+validator.isBase64("sample");
+
+validator.isHexadecimal("sample");
+
+validator.isHexColor("sample");
+
+validator.isLowercase("sample");
+
+validator.isUppercase("sample");
+
+validator.isInt("sample");
+
+validator.isFloat("sample");
+
+validator.isDivisibleBy("sample", 2);
+
+validator.isNull("sample");
+
+validator.isLength("sample", 3, 5);
+
+validator.isByteLength("sample", 3);
+
+validator.isUUID("sample");
+
+validator.isDate("sample");
+
+validator.isAfter("sample");
+
+validator.isBefore("sample");
+
+validator.isIn("sample", []);
+
+validator.isCreditCard("sample");
+
+validator.isISBN("sample");
+
+validator.isJSON("sample");
+
+validator.isMultibyte("sample");
+
+validator.isAscii("sample");
+
+validator.isFullWidth("sample");
+
+validator.isHalfWidth("sample");
+
+validator.isVariableWidth("sample");
+
+validator.isSurrogatePair("sample");
+
+validator.isMongoId("sample");
+
+validator.toString(123);
+
+validator.toDate(1225);
+
+validator.toFloat('011');
+
+validator.toInt('aa');
+
+validator.toBoolean('yes!');
+
+validator.trim('  triming  ');
+
+validator.ltrim('  triming  ');
+
+validator.rtrim('  triming  ');
+
+validator.escape('<script>');
+
+validator.stripLow('\x7Ffoo\x02');
+
+validator.whitelist('ab', 'abcdef');
+
+validator.blacklist('abc', 'abcdef');
+
+validator.normalizeEmail('!');
diff --git a/validator/validator.d.ts b/validator/validator.d.ts
new file mode 100644
index 0000000000..05a391fa45
--- /dev/null
+++ b/validator/validator.d.ts
@@ -0,0 +1,190 @@
+// Type definitions for validator.js v3.22.1
+// Project: https://github.com/chriso/validator.js
+// Definitions by: tgfjt <https://github.com/tgfjt>
+// Definitions: https://github.com/borisyankov/DefinitelyTyped
+
+// options for #isURL
+interface IURLoptions {
+  protocols?: string[]
+  require_tld?: boolean
+  require_protocol?: boolean
+  allow_underscores?: boolean
+}
+
+// options for isFQDN
+interface IFQDNoptions {
+  require_tld?: boolean
+  allow_underscores?: boolean
+}
+
+// options for normalizeEmail
+interface IEmailoptions {
+  lowercase?: boolean
+}
+
+// callback type for #extend 
+interface IExtendCallback {
+  (argv: string): any
+}
+
+// return function for #extend
+interface IExtendFunc {
+  (argv: string): boolean
+}
+
+interface IValidatorStatic {
+  // add your own validators
+  extend(name: string, fn: IExtendCallback): IExtendFunc;
+
+  // check if the string matches the comparison.
+  equals(str: string, comparison: any): boolean;
+
+  // check if the string contains the seed.
+  contains(str: string, elem: any): boolean;
+
+  // check if string matches the pattern.
+  matches(str: string, pattern: any, modifiers?: string): boolean;
+
+  // check if the string is an email.
+  isEmail(str: string): boolean;
+
+  // check if the string is an URL.
+  isURL(str: string, options?: IURLoptions): boolean;
+
+  // check if the string is a fully qualified domain name (e.g. domain.com).
+  isFQDN(str: string, options?: IFQDNoptions): boolean;
+
+  // check if the string is an IP (version 4 or 6).
+  isIP(str: string, version?: number): boolean;
+
+  // check if the string contains only letters (a-zA-Z).
+  isAlpha(str: string): boolean;
+
+  // check if the string contains only numbers.
+  isNumeric(str: string): boolean;
+
+  // check if the string contains only letters and numbers.
+  isAlphanumeric(str: string): boolean;
+
+  // check if a string is base64 encoded.
+  isBase64(str: string): boolean;
+
+  // check if the string is a hexadecimal number.
+  isHexadecimal(str: string): boolean;
+
+  // check if the string is a hexadecimal color.
+  isHexColor(str: string): boolean;
+
+  // check if the string is lowercase.
+  isLowercase(str: string): boolean;
+
+  // check if the string is uppercase.
+  isUppercase(str: string): boolean;
+
+  // check if the string is an integer.
+  isInt(str: string): boolean;
+
+  // check if the string is a float.
+  isFloat(str: string): boolean;
+
+  // check if the string is a number that's divisible by another.
+  isDivisibleBy(str: string, number: number): boolean;
+
+  // check if the string is null.
+  isNull(str: string): boolean;
+
+  // check if the string's length falls in a range. Note: this function takes into account surrogate pairs.
+  isLength(str: string, min: number, max?: number): boolean;
+
+  // check if the string's length (in bytes) falls in a range.
+  isByteLength(str: string, min: number, max?: number): boolean;
+
+  // check if the string is a UUID (version 3, 4 or 5).
+  isUUID(str: string, version?: number): boolean;
+
+  // check if the string is a date.
+  isDate(str: string): boolean;
+
+  // check if the string is a date that's after the specified date (defaults to now).
+  isAfter(str: string, date?: Date): boolean;
+
+  // check if the string is a date that's before the specified date.
+  isBefore(str: string, date?: Date): boolean;
+
+  // check if the string is in a array of allowed values.
+  isIn(str: string, values: any[]): boolean;
+
+  // check if the string is a credit card.
+  isCreditCard(str: string): boolean;
+
+  // check if the string is an ISBN (version 10 or 13).
+  isISBN(str: string, version?: number): boolean;
+
+  // check if the string is valid JSON (note: uses JSON.parse).
+  isJSON(str: string): boolean;
+
+  // check if the string contains one or more multibyte chars.
+  isMultibyte(str: string): boolean;
+
+  // check if the string contains ASCII chars only.
+  isAscii(str: string): boolean;
+
+  // check if the string contains any full-width chars.
+  isFullWidth(str: string): boolean;
+
+  // check if the string contains any half-width chars.
+  isHalfWidth(str: string): boolean;
+
+  // check if the string contains a mixture of full and half-width chars.
+  isVariableWidth(str: string): boolean;
+
+  // check if the string contains any surrogate pairs chars.
+  isSurrogatePair(str: string): boolean;
+
+  // check if the string is a valid hex-encoded representation of a MongoDB ObjectId.
+  isMongoId(str: string): boolean;
+
+  // convert the input to a string.
+  toString(input: any): string;
+
+  // convert the input to a date, or null if the input is not a date.
+  toDate(input: any): any; // Date or null
+
+  // convert the input to a float, or NaN if the input is not a float.
+  toFloat(input:any): number; // number or NaN
+
+  // convert the input to an integer, or NaN if the input is not an integer.
+  toInt(input:any, radix?: number): number; // number or NaN
+
+  // convert the input to a boolean.
+  toBoolean(input:any, strict?: boolean): boolean;
+
+  // trim characters (whitespace by default) from both sides of the input.
+  trim(input: any, chars?: string): string;
+
+  // trim characters from the left-side of the input.
+  ltrim(input: any, chars?: string): string;
+
+  // trim characters from the right-side of the input.
+  rtrim(input: any, chars?: string): string;
+
+  // replace <, >, &, ' and " with HTML entities.
+  escape(input: string): string;
+
+  // remove characters with a numerical value < 32 and 127
+  stripLow(input: string, keep_new_lines?: boolean): string;
+
+  // remove characters that do not appear in the whitelist.
+  whitelist(input: string, chars: string): string;
+
+  // remove characters that appear in the blacklist. 
+  blacklist(input: string, chars: string): string;
+
+  // canonicalize an email address.
+  normalizeEmail(email: string, options?: IEmailoptions): string;
+}
+
+declare module "validator" {
+  var validator: IValidatorStatic;
+  export = validator;
+}