1.20.0 (2026-04-01)

New features

• add new pipe validation rule for sequential validate-transform-validate workflows. #359

Bug fixes

• fix crash when enum values contain double-quotes. #293
• fix TypeScript ValidationSchema type — remove | any that made the mapped type useless. #334

Other changes

• replace Rollup with esbuild for build pipeline. #360
• replace Jest with Vitest for test framework. #360
• migrate ESLint 8 to ESLint 9 flat config. #360
• update devDependencies: TypeScript 5.7, Prettier 3, Nodemon 3, tsd 0.31, benchmarkify 4. #360
• update CI Node.js matrix to 20.x, 22.x, 24.x. #360
• add additional UUID v7 validation tests. #358

1.19.1 (2025-04-30)

Changes

• fix false negative check on UUID v7 and v8 #351

1.19.0 (2024-07-28)

Changes

• shorthand label hotfix. #345
• fix deprecated substr. #346
• improved custom function with array and global custom functions. More info #332

1.18.0 (2024-04-21)

Changes

• improve typing. #339
• allow to add metas in the schema. #341

1.17.0 (2023-04-23)

Changes

• add considerNullAsAValue to Validation constructor options. #317
• add type definition for haltOnFirstError on Validator constructor. #322

1.16.0 (2022-12-17)

Changes

• add convert to array rule. #314

1.15.0 (2022-08-30)

Changes

• fixed bug in record rule. #307
• add label support for error messages. More info #306

1.14.0 (2022-08-27)

Changes

• fix: Multi-schema nullable validators not working as expected. #303
• add new haltOnFirstError option (https://github.com/icebob/fastest-validator#halting). #304

1.13.0 (2022-08-15)

Changes

• update dev dependencies.
• update d.ts
• fixing string enum check in case of optional field. #284
• date rule add convert string to number for timestamp. #286
• fix(multi): item rule has custom checker will throw error if validate. #290
• fix backward compatibility issue. #298
• add new Record rule. #300

1.12.0 (2021-10-17)

Changes

• update dev dependencies.
• add parameters to dynamic default value function. E.g: age: (schema, field, parent, context) => { ... }
• fix typescript definitions. #269, #270, #261
• fix multi validate with object strict remove. #272
• add normalize method. #275 E.g.: validator.normalize({ a: "string[]|optional" })

1.11.1 (2021-07-14)

Changes

• fix debug mode. #237
• fix object "toString" issue. #235
• remove Node 10 from CI pipeline.
• refactoring the typescript definitions. #251
• update examples in readme. #255

---

1.11.0 (2021-05-11)

Async custom validator supports

const schema = {
    // Turn on async mode for this schema
    $$async: true,
    name: {
        type: "string",
        min: 4,
        max: 25,
        custom: async (v) => {
            await new Promise(resolve => setTimeout(resolve, 1000));
            return v.toUpperCase();
        }
    },

    username: {
        type: "custom",
        custom: async (v) => {
            // E.g. checking in the DB that whether is unique.
            await new Promise(resolve => setTimeout(resolve, 1000));
            return v.trim();
        }
    },
}

The compiled check function has an async property to detect this mode. If true it returns a Promise.

const check = v.compile(schema);
console.log("Is async?", check.async);

Meta-information for custom validators

You can pass any extra meta information for the custom validators which is available via context.meta.

const schema = {
    name: { type: "string", custom: (value, errors, schema, name, parent, context) => {
        // Access to the meta
        return context.meta.a;
    } },
};
const check = v.compile(schema);

const res = check(obj, {
    // Passes meta information
    meta: { a: "from-meta" }
});

Changes

• support default and optional in tuples and arrays #226
• fix that this points to the Validator instance in custom functions #231

---

1.10.1 (2021-03-22)

Changes

• fix issue with regex pattern in string rule #221
• fix returned value issue in email rule in case of empty: false #224

---

1.10.0 (2021-02-03)

Changes

• fix issue in multiple custom validator #203
• Add min, max property to email rule #213
• Add base64 property to string rule #214

---

1.9.0 (2020-11-16)

Changes

• uuid rule supports version 0 in #201 by @intech

---

1.8.0 (2020-10-18)

New nullable rule attribute in #185

const schema = {
    age: { type: "number", nullable: true }
}
v.validate({ age: 42 }, schema); // Valid
v.validate({ age: null }, schema); // Valid
v.validate({ age: undefined }, schema); // Fail because undefined is disallowed
v.validate({}, schema); // Fail because undefined is disallowed

Changes

• Shorthand for array foo: "string[]" // means array of string in #190
• allow converting objectID to string in in #196

---

1.7.0 (2020-08-30)

Changes

• New currency rule by @ishan-srivastava in #178
• fix issue in any rule #185
• update dev deps

---

1.6.1 (2020-08-11)

Changes

• Fix issue with ObjectID rule

---

1.6.0 (2020-08-06)

New objectID rule

You can validate BSON/MongoDB ObjectID's

Example

const  { ObjectID } = require("mongodb") // or anywhere else 
const schema = {
    id: {
        type: "objectID",
        ObjectID // passing the ObjectID class
    }  
}
const check = v.compile(schema);
check({ id: "5f082780b00cc7401fb8e8fc" }) // ok
check({ id: new ObjectID() }) // ok
check({ id: "5f082780b00cc7401fb8e8" }) // Error

Dynamic default value

You can use dynamic default value by defining a function that returns a value.

Example In the following code, if createdAt field not defined in object`, the validator sets the current time into the property:

const schema = {
    createdAt: {
        type: "date",
        default: () => new Date()
    }
};
const obj = {}
v.validate(obj, schema); // Valid
console.log(obj);
/*
{
    createdAt: Date(2020-07-25T13:17:41.052Z)
}
*/

Changes

• Add support for uuid v6. #181
• Add addMessage method for using in plugins #166
• Fix uppercase uuid issue. #176
• Add singleLine property to string rule. #180

Credits

Many thanks to @intech and @erfanium for contributing.

---

1.5.1 (2020-06-19)

Changes

• Fixing issue with pattern & empty handling in string rule #165

---

1.5.0 (2020-06-18)

New tuple validation rule

Thanks for @Gamote, in this version there is a new tuple. This rule checks if a value is an Array with the elements order as described by the schema.

Example

const schema = {
    grade: { type: "tuple", items: ["string", "number", "string"] }
};

const schema = {
    location: { type: "tuple", empty: false, items: [
        { type: "number", min: 35, max: 45 },
        { type: "number", min: -75, max: -65 }
    ] }
}

Define aliases & custom rules in constructor options #162

You can define aliases & custom rules in constructor options instead of using v.alias and v.add.

Example

const v = new Validator({
    aliases: {
        username: {
            type: 'string',
            min: 4,
            max: 30
        }
    },
    customRules: {
        even: function({ schema, messages }, path, context) {
            return {
                source: `
                    if (value % 2 != 0)
                        ${this.makeError({ type: "evenNumber",  actual: "value", messages })}

                    return value;
                `
            };
        })
    }
});

Support plugins

Thanks for @erfanium, you can create plugin for fastest-validator.

Example

// Plugin Side
function myPlugin(validator){
    // you can modify validator here
    // e.g.: validator.add(...)
    // or  : validator.alias(...)
}
// Validator Side
const v = new Validator();
v.plugin(myPlugin)

Changes

• Allow empty property in string rule with pattern #149
• Add empty property to url and email rule #150
• Fix custom rule issue when multiple rules #155
• Update type definition #156

---

1.4.2 (2020-06-03)

Changes

• added Deno example to readme.
• added minProps and maxProps by @alexjab #142
• shorthand for nested objectsby @erfanium #143
• typescript generics for compile method by @Gamote #146

---

1.4.1 (2020-05-13)

Changes

• Fix custom function issue in array rule and in root-level #136, #137

---

1.4.0 (2020-05-08)

New custom function signature

Thanks for @erfanium, in this version there is a new signature of custom check functions. In this new function you should always return the value. It means you can change the value, thus you can also sanitize the input value.

Old custom function:

const v = new Validator({});

const schema = {
    weight: {
        type: "custom",
        minWeight: 10,
        check(value, schema) {
            return (value < schema.minWeight)
                ? [{ type: "weightMin", expected: schema.minWeight, actual: value }]
                : true;
        }
    }
};

New custom function:

const v = new Validator({
    useNewCustomCheckerFunction: true, // using new version
});

const schema = {
    name: { type: "string", min: 3, max: 255 },
    weight: {
        type: "custom",
        minWeight: 10,
        check(value, errors, schema) {
            if (value < minWeight) errors.push({ type: "weightMin", expected: schema.minWeight, actual: value });
            if (value > 100) value = 100
            return value
        }
    }
};

Please note: the old version will be removed in the version 2.0.0!

The signature is used in custom function of built-in rules.

const v = new Validator({
    useNewCustomCheckerFunction: true // using new version
});

const schema = {
    phone: { type: "string", length: 15, custom(v, errors) => {
        if (!v.startWith("+")) errors.push({ type: "phoneNumber" })
        return v.replace(/[^\d+]/g, ""); // Sanitize: remove all special chars except numbers
    } }	
};

---

1.3.0 (2020-04-29)

Changes

• Add new class rule to check the instance of value #126
• Updated typescript definitions #127 #129
• Fix deep-extend function to detect objects better. #128
• Add hex check to string rule #132

---

1.2.0 (2020-04-05)

Changes

• Add default settings for built-in rules #120 by @erfanium
• Updated typescript definitions #122 by @FFKL

---

1.1.0 (2020-03-22)

Changes

• New user-defined 'alias' feature #118 by @erfanium
• Add custom validation function for built-in rules #119 by @erfanium

---

1.0.2 (2020-02-09)

Changes

• Fix string with pattern where regular expression contains a double quote #111 by @FranzZemen

---

1.0.1 (2020-02-01)

Changes

• fix missing field property in custom rules #109

---

1.0.0 (2019-12-18)

Changes

• add unique validation in array rule #104

---

1.0.0-beta4 (2019-11-17)

Changes

• fix optional multi rule.
• fix array rule return value issue (again).

---

1.0.0-beta2 (2019-11-15)

Changes

• fix array rule return value issue.

---

1.0.0-beta1 (2019-11-15)

The full library has been rewritten. It uses code generators in order to be much faster.

Breaking changes

This new version contains several breaking changes.

Rule logic changed

The rule codes have been rewritten to code generator functions. Therefore if you use custom validators, you should rewrite them after upgrading.

Convert values

The number, boolean and date rules have a convert: true property. In the previous version it doesn't modify the value in the checked object, just converted the value to the rules. In the version 1.0 this property converts the values in the checked object, as well.

New

Sanitizations

The sanitization function is implemented. There are several rules which contains sanitizers. Please note, the sanitizers change the original checked object values.

Rule	Property	Description
boolean	convert	Convert the value to a boolean.
number	convert	Convert the value to a number.
date	convert	Convert the value to a date.
string	trim	Trim the value.
string	trimLeft	Left trim the value.
string	trimRight	Right trim the value.
string	lowercase	Lowercase the value.
string	uppercase	Uppercase the value.
string	localeLowercase	Lowercase the value with String.toLocaleLowerCase.
string	localeUppercase	Uppercase the value with String.toLocaleUpperCase.
string	padStart	Left padding the value.
string	padEnd	Right padding the value.
string	convert	Convert the value to a string.
email	normalize	Trim & lowercase the value.
forbidden	remove	Remove the forbidden field.
object	strict: "remove"	Remove additional properties in the object.
*	default	Use this default value if the value is null or undefined.

Root element validation

Basically the validator expects that you want to validate a Javascript object. If you want others, you can define the root level schema, as well. In this case set the $$root: true property.

Example to validate a string variable instead of object

const schema = {
    $$root: true,
    type: "string", 
    min: 3, 
    max: 6
};

v.validate("John", schema); // Valid
v.validate("Al", schema); // Fail, too short.

Enhanced shorthand types

You can use string-based shorthand validation definitions in the schema with properties.

{
    password: "string|min:6",
    age: "number|optional|integer|positive|min:0|max:99",

    retry: ["number|integer|min:0", "boolean"] // multiple types
}

Other changes

New equal rule

It checks the value equal (==) to a static value or another property. The strict property uses === to check values.

Example with static value:

const schema = {
    agreeTerms: { type: "equal", value: true, strict: true } // strict means `===`
}

v.validate({ agreeTerms: true }, schema); // Valid
v.validate({ agreeTerms: false }, schema); // Fail

Example with other field:

const schema = {
    password: { type: "string", min: 6 },
    confirmPassword: { type: "equal", field: "password" }
}

v.validate({ password: "123456", confirmPassword: "123456" }, schema); // Valid
v.validate({ password: "123456", confirmPassword: "pass1234" }, schema); // Fail

properties in object rule

You can use the properties property besides the props property in the object rule.

---

0.6.19 (2019-10-25)

Changes

• update typescript definitions.
• add "actual" variable into string messages.

---

0.6.18 (2019-09-30)

Changes

• add mac and luhn rules by @intech;
• update dev dependencies.
• fix custom rule custom messages issue. #83

---

0.6.17 (2019-03-20)

Changes

• fix typescript definitions.
• fix strict property compilation.

---

0.6.16 (2019-03-01)

Changes

• fix typescript definitions.

---

0.6.15 (2019-02-13)

Changes

• fix uuid rule. #60
• fix typescript definitions. #59

---

0.6.14 (2019-02-07)

Changes

• add uuid rule by @intech. #43
• fix typescript exposing by @darky. #58
• add personalised error messages per field by @ispyinternet. #57
• add strict object validation by @fabioanderegg & @mbaertschi. #47
• linting sources.

---

0.6.13 (2019-01-22)

Changes

• add error message for url rule.
• add numeric attribute to string rule.
• add alpha, alphanum & alphadash attributes to string rule.
• add index.d.ts file.
• fix multiple validator with different messages issue.

---

0.6.12 (2018-12-04)

Changes

• support recursive schemas by @andersnm
• fix irregular object property names

---

0.6.11 (2018-10-25)

Changes

• performance improvements by @andersnm
• rewritten schema compiling by @andersnm

---

0.6.10 (2018-06-25)

Changes

• fix #27 - multiple optional validators

---

0.6.9 (2018-06-07)

Changes

• fix #25 - multiple optional validators
• Add new enum rule

      { type: "enum", values: ["male", "female"] }
  

---

0.6.7 (2018-05-29)

Changes

• supports multiple object validators #22 by @mauricedoepke

  const schema = {
      list: [
          { 
              type: "object",
              props: {
                  name: {type: "string"},
                  age: {type: "number"},
              } 
          },
          { 
              type: "object",
              props: {
                  country: {type: "string"},
                  code: {type: "string"},
              } 
          }
      ]
  };
  

---

0.6.6 (2018-04-04)

Access to the original object in custom validator #5

const schema = {
    email: { 
        type: "custom", 
        check(value, schema, stack, obj) {
            return obj.username || obj.email ? null : this.makeError(...);
        }
    }
};