Speech To Text Using React Native CLI and Expo CLI Mobile App Builder Guide

Explore the power of Speech Text Using React Native CLI and Expo CLI Mobile App Builder in this comprehensive guide. Learn how to build speech recognition apps with ease.

In the ever-evolving world of mobile app development, harnessing the capabilities of tools like React Native CLI and Expo CLI can be a game-changer. One fascinating application of these tools is converting speech into text, and in this guide, we'll dive into the intricacies of Speech To Text Using React Native CLI and Expo CLI Mobile App Builder.

We'll explore every aspect of this topic, providing expert insights, tips, and answers to common questions. So, let's embark on this journey of speech recognition and app development!

Demo App 

Speech-to-Text Example

Microphone: off

Here's a complete file structure and code setup for a React Native Expo app that uses the react-speech-recognition library for speech-to-text functionality:

File Structure:

SpeechToTextApp/ ├── App.js ├── components/ │ └── SpeechRecognition.js ├── node_modules/ ├── package.json ├── package-lock.json ├── app.json

To install the dependencies for the above code, you can follow these steps:

Navigate to the root directory of your React Native Expo project (the SpeechToTextApp directory in this case) using your command line or terminal.

Run the following command to install the required dependencies:

npm install

This command will read the package.json file and install the specified dependencies, including Expo and react-speech-recognition.

After the installation is complete, you can start your Expo app using the following command:

This command will start your development server and display a QR code that you can scan with the Expo Go app on your mobile device or use with an Android or iOS emulator.

Your React Native Expo app, as configured in the provided code, will run, and you'll see the user interface for speech-to-text functionality on your device or emulator.


App.js: This is the main entry point for your Expo app, and it sets up your navigation.

import React from 'react'; import { View, Text } from 'react-native'; import SpeechRecognitionComponent from './components/SpeechRecognition'; export default function App() { return ( <View style={{ flex: 1, alignItems: 'center', justifyContent: 'center' }}> <Text>Speech to Text Example</Text> <SpeechRecognitionComponent /> </View> ); }

 components/SpeechRecognition.js: This custom component handles speech recognition functionality.

import React from 'react'; import { View, Text, Button } from 'react-native'; import SpeechRecognition, { useSpeechRecognition } from 'react-speech-recognition'; const SpeechRecognitionComponent = () => { const { transcript, listening, resetTranscript, browserSupportsSpeechRecognition, } = useSpeechRecognition(); const handleStartListening = () => { if (browserSupportsSpeechRecognition) { SpeechRecognition.startListening(); } }; const handleStopListening = () => { SpeechRecognition.stopListening(); }; return ( <View> <Text>Microphone: {listening ? 'on' : 'off'}</Text> <Button title="Start" onPress={handleStartListening} /> <Button title="Stop" onPress={handleStopListening} /> <Button title="Reset" onPress={resetTranscript} /> <Text>Transcript: {transcript}</Text> </View> ); }; export default SpeechRecognitionComponent;

package.json: This file defines your project's metadata and dependencies. Ensure you have the necessary dependencies installed.

{ "name": "SpeechToTextApp", "version": "1.0.0", "description": "A React Native Expo app for speech-to-text conversion.", "main": "App.js", "scripts": { "start": "expo start", "android": "expo start --android", "ios": "expo start --ios", "web": "expo start --web" }, "dependencies": { "expo": "^42.0.1", "react": "16.13.1", "react-dom": "16.13.1", "react-native": "https://github.com/expo/react-native/archive/sdk-42.0.1.tar.gz", "react-native-unimodules": "~0.14.5", "react-speech-recognition": "^3.10.0" }, "devDependencies": { "@babel/core": "^7.12.9" }, "private": true }

 app.json: This file contains configuration information for your Expo app.

{ "expo": { "name": "SpeechToTextApp", "slug": "speech-to-text-app", "platforms": ["ios", "android", "web"], "version": "1.0.0", "orientation": "portrait", "icon": "./assets/icon.png", "splash": { "image": "./assets/splash.png", "resizeMode": "contain" }, "updates": { "fallbackToCacheTimeout": 0 }, "assetBundlePatterns": ["**/*"], "ios": { "supportsTablet": true }, "web": { "favicon": "./assets/favicon.png" } } }

 assets: You can place your app's assets, such as images, in this folder.

After setting up your files and dependencies, you can run your app using the following commands:

To Run App

npx expo start

This will start your Expo development server, and you can preview your app on your device or simulator. You'll see the main screen with a "Start" button to begin speech recognition, a "Stop" button to end it, a "Reset" button to clear the transcript, and a display area where the transcribed text will appear as you speak into the microphone.

Ensure you have Expo CLI installed (npm install -g expo-cli) and have set up the necessary development environment for React Native and Expo before running the app.

Speech To Text Using React Native CLI and Expo CLI Mobile App Builder

When it comes to building mobile applications with speech recognition capabilities, React Native CLI and Expo CLI offer a seamless and efficient solution. These development tools enable developers to create cross-platform applications with the added feature of converting spoken words into text. Let's delve deeper into the intricacies of this innovative technology.

Creating a Speech Recognition App

Speech recognition apps have a broad range of applications, from transcription services to voice assistants. To get started with building your own, you'll need to follow these key steps:

Setting Up Your Development Environment

  • Before you begin, ensure you have React Native CLI and Expo CLI installed on your system.
  • Create a new project using the CLI tools.
  • Installing Necessary Libraries

Utilize libraries such as 'react-native-voice' to enable speech recognition capabilities.

Install Expo's 'expo-speech' package to access speech-to-text functionality.

Requesting Permissions

To use the device's microphone, request the necessary permissions from the user.

Building the User Interface

Design your app's user interface, integrating components for voice input and text output.

Implementing Speech Recognition

Use the 'react-native-voice' library to initiate speech recognition.

Set up event listeners to capture speech input.

Converting Speech to Text

  • Once speech is recognized, convert it to text using the 'expo-speech' package.
  • Display the converted text on the user interface.
  • Testing and Debugging
  • Thoroughly test your app, ensuring that speech recognition is accurate and responsive.
  • Debug any issues that may arise during testing.

By following these steps, you can create a functional speech recognition app using React Native CLI and Expo CLI.

Benefits of Speech Recognition in Mobile Apps

The integration of speech-to-text functionality in mobile apps offers numerous benefits, both for developers and end-users. Here are some advantages:

Enhanced User Experience: Users can interact with the app using voice commands, making the user experience more intuitive and convenient.

Accessibility: Speech recognition apps are highly accessible, benefiting individuals with disabilities.

Efficiency: Transcribing spoken words into text can save time and effort, especially in tasks like note-taking.

Multilingual Support: These apps can support multiple languages, expanding the potential user base.


Q: How accurate is speech recognition in mobile apps?

A: Speech recognition has significantly improved over the years and is now quite accurate. However, accuracy may vary based on the quality of the microphone and the ambient noise.

Q: Can I use speech recognition for languages other than English?

A: Yes, many speech recognition libraries and APIs support multiple languages, so you can build apps in various languages.

Q: Are there privacy concerns with speech recognition?

A: It's essential to inform users and obtain their consent before recording and processing their speech for privacy reasons.

Q: Can I integrate speech recognition with third-party services?

A: Yes, many services offer APIs for speech recognition, allowing you to integrate advanced features into your app.

Q: How can I improve the accuracy of speech recognition in my app?

A: Ensure a quiet environment, use noise-canceling technology, and provide clear instructions for users to enhance accuracy.

Q: Are there any legal considerations when using speech recognition in apps?

A: Depending on your location and the nature of your app, there may be legal considerations, such as data privacy and consent. It's crucial to research and comply with relevant laws and regulations.


Speech To Text Using React Native CLI and Expo CLI Mobile App Builder opens up exciting possibilities for developers. Whether you're looking to build a voice-controlled note-taking app or a multilingual voice assistant, these tools empower you to create innovative solutions. The integration of speech recognition can enhance user experiences, accessibility, and efficiency. By following the steps outlined in this guide and considering the FAQs, you'll be well on your way to developing your own speech recognition app.

If you're passionate about mobile app development and innovation, exploring Speech To Text Using React Native CLI and Expo CLI Mobile App Builder is a must. So, roll up your sleeves and get ready to make your app projects more engaging and user-friendly than ever before!

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