react-native-quick-base64

A blazing fast, native Base64 implementation for React Native using C++ and JSI.

This library is ~16x faster than base64-js on an iPhone 15 Pro Max simulator.
Try the benchmarks in the example app.

| iPhone | Android |
| ------------------------------------------------- | --------------------------------------------------- |
| !iPhone | !Android |

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Features

- ⚡ Native C++/JSI implementation for maximum performance
- 🧠 Automatically installs its JSI bindings at runtime
- 🧩 Drop-in replacement for base64-js with matching API
- 🔒 No additional native setup or linking required

> ℹ️ Heads-up:
> Starting with recent versions of Hermes, btoa and atob are natively available in the JS runtime.
> You likely don't need to use the versions provided by this library anymore unless you're running on an older engine or want consistent behavior across platforms.
> These methods will remain in the package for compatibility but are considered deprecated.

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Installation

``bash
npm install react-native-quick-base64
`

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This module installs its native bindings automatically.
Simply importing the library is enough to activate the native backend.
Add it to your root entry point file or your first \_layout.tsx.

`js
import 'react-native-quick-base64' // triggers native JSI install to global namespace
`

You can also import individual helpers:

`tsx
import { fromByteArray, toByteArray } from 'react-native-quick-base64'
`

$3

`tsx
import { btoa, atob } from 'react-native-quick-base64'

const base64 = btoa('foo')
const decoded = atob(base64)
`

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API

Compatible with base64-js.

$3

Returns the length of the byte array that corresponds to the base64 string.

$3

Converts a base64 string into a Uint8Array.
If removeLinebreaks is true, all \n characters are removed first.

$3

Converts a byte array into a base64 string.
If urlSafe is true, the output uses a URL-safe base64 charset.

$3

Encodes a string into base64 format.

> Avoid using this unless you're on an older JS engine.
> Use fromByteArray(new TextEncoder().encode(...)) instead for better encoding control.

$3

Decodes a base64 string into a UTF-8 string.

> Avoid using this unless you're on an older JS engine.
> Use TextDecoder + toByteArray() for more robust decoding.

$3

Adds global btoa and atob functions

`ts
import { shim } from 'react-native-quick-base64'

shim()

btoa('foo') // available globally
`

$3

Removes trailing = or .` padding from base64 or base64url-encoded strings.

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Contributing

See the contributing guide to learn how to contribute to the repository and the development workflow.

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License

MIT © Takuya Matsuyama