is-base64

What is is-base64?

The is-base64 npm package is a utility for checking if a given string is a valid Base64 encoded string. It provides simple and straightforward methods to validate Base64 strings, making it useful for applications that need to handle or verify Base64 encoded data.

What are is-base64's main functionalities?

Validation of Base64 Strings

This feature allows you to check if a given string is a valid Base64 encoded string. The function returns true if the string is valid Base64 and false otherwise.

const isBase64 = require('is-base64');

const validBase64 = 'SGVsbG8gd29ybGQ=';
const invalidBase64 = 'Hello world';

console.log(isBase64(validBase64)); // true
console.log(isBase64(invalidBase64)); // false

Validation with Options

This feature allows you to validate Base64 strings with additional options. For example, you can specify whether to allow empty strings as valid Base64.

const isBase64 = require('is-base64');

const validBase64 = 'SGVsbG8gd29ybGQ=';
const invalidBase64 = 'Hello world';

console.log(isBase64(validBase64, { allowEmpty: false })); // true
console.log(isBase64('', { allowEmpty: false })); // false

Other packages similar to is-base64

base64-js

The base64-js package provides utilities for encoding and decoding Base64 strings. Unlike is-base64, which focuses solely on validation, base64-js offers functionality for both encoding and decoding Base64 data.

js-base64

The js-base64 package is a comprehensive library for Base64 encoding and decoding. It provides methods for encoding strings to Base64 and decoding Base64 strings back to their original form. This package offers more functionality compared to is-base64, which is limited to validation.

base-64

The base-64 package is a lightweight library for encoding and decoding Base64 strings. It is similar to js-base64 but with a smaller footprint. While is-base64 focuses on validation, base-64 provides encoding and decoding capabilities.

README

is-base64

Predicate that returns true if base64 string.

Install

npm install is-base64

Usage

var isBase64 = require('is-base64');

var string = 'iVBORw0KGgoAAAAN ... kSuQmCC';
var stringWithMime = 'data:image/png;base64,iVBORw0KGgoAAAA ... AAElFTkSuQmCC';

console.log(isBase64(string)); // true
console.log(isBase64(stringWithMime)); // false
console.log(isBase64(stringWithMime, {allowMime: true})); // true
console.log(isBase64(string, {mimeRequired: true})); // false
console.log(isBase64(stringWithMime, {mimeRequired: true})); // true
console.log(isBase64('1342234')); // false
console.log(isBase64('afQ$%rfew')); // false
console.log(isBase64('dfasdfr342')); // false
console.log(isBase64('uuLMhh==')); // true
console.log(isBase64('uuLMhh')); // false
console.log(isBase64('uuLMhh', {paddingRequired: false})); // true
console.log(isBase64('')); // true
console.log(isBase64('', {allowEmpty: false})); // false

API

isBase64(string, options)

• {string} string - string to check if is valid base64 string

• {object} [options]

  • [options.allowEmpty=true] {boolean} - returns true for empty string
  • [options.allowMime=false] {boolean} - returns true for valid strings with optional mime
  • [options.mimeRequired=false] {boolean} - returns true for valid strings with mime
  • [options.paddingRequired=true] {boolean} - returns true for valid strings with valid padding

CLI

Install CLI:

npm install -g is-base64

CLI example:

$ is-base64 aGVsbG8gd29ybGQ=
true

Piping example:

$ echo aGVsbG8gd29ybGQ= | is-base64
true

FAQ

• Q: Why is empty string "" a valid base64 string by default?

  • A: According to RFC 4648 Section 10, the following is valid test vector:

    BASE64("") = ""
    

License

MIT