react-native-fast-tflite

A high-performance TensorFlow Lite library for React Native, built with Nitro Modules.

• ⚡ Powered by Nitro Modules
• 💨 Zero-copy ArrayBuffers
• 🔧 Uses the low-level C/C++ TensorFlow Lite core API for direct memory access
• 🔄 Supports swapping out TensorFlow Models at runtime
• 🖥️ Supports GPU-accelerated delegates (CoreML/Metal/OpenGL)
• 📸 Easy VisionCamera integration

Migrating from v2

If you are upgrading from v2, see the Migration Guide for breaking changes and upgrade steps.

Installation

1. Add the npm packages:

   yarn add react-native-fast-tflite react-native-nitro-modules
   

2. In metro.config.js, add tflite as a supported asset extension:

   module.exports = {
     // ...
     resolver: {
       assetExts: ['tflite', // ...
       // ...
   

   This allows you to drop .tflite files into your app and swap them out at runtime without rebuilding. 🔥
3. (Optional) To enable GPU delegates, see Using GPU Delegates below.
4. Run your app (yarn android / npx pod-install && yarn ios)

Usage

1. Find a TensorFlow Lite (.tflite) model. There are thousands of public models on tfhub.dev.

2. Drag your model into your app's asset folder (e.g. src/assets/my-model.tflite)

3. Load the Model:

   // Option A: Standalone Function
   const model = await loadTensorflowModel(require('assets/my-model.tflite'), [])
   
   // Option B: Hook in a Function Component
   const plugin = useTensorflowModel(require('assets/my-model.tflite'), [])
   

4. Call the Model:

   const inputData: ArrayBuffer = ...
   const outputData = await model.run([inputData])
   console.log(outputData)
   

Loading Models

Models can be loaded from the React Native bundle via require(..), or any URI/URL (http://.. or file://..):

// Asset from React Native Bundle
loadTensorflowModel(require('assets/my-model.tflite'), [])
// File on the local filesystem
loadTensorflowModel({ url: 'file:///var/mobile/.../my-model.tflite' }, [])
// Remote URL
loadTensorflowModel(
  { url: 'https://tfhub.dev/google/lite-model/object_detection_v1.tflite' },
  []
)

Loading a Model is asynchronous since buffers need to be allocated. Make sure to handle errors when loading.

Input and Output data

TensorFlow uses tensors as input and output. Since TensorFlow Lite is optimized for fixed-size byte buffers, you are responsible for interpreting the raw data yourself.

Input and output values are passed as ArrayBuffer. To inspect tensor shapes, open your model in Netron.

For example, the object_detection_mobile_object_localizer_v1_1_default_1.tflite model on tfhub.dev has 1 input tensor and 4 output tensors:

In the description on tfhub.dev we can find the description of all tensors:

From that we know we need a 192 x 192 input image with 3 bytes per pixel (RGB).

Usage (VisionCamera)

If you're using this model with a VisionCamera Frame Processor, you need to convert the Frame to the model's expected input size. Use vision-camera-resizer to do the conversion:

import { Camera, useFrameOutput } from 'react-native-vision-camera'
import { useResizer } from 'react-native-vision-camera-resizer'
import { useTensorflowModel } from 'react-native-fast-tflite'

const objectDetection = useTensorflowModel(require('object_detection.tflite'), [])

// 1. Create a resizer that converts Frames to 192x192x3 (RGB, uint8)
const { resizer } = useResizer({
  width: 192,
  height: 192,
  channelOrder: 'rgb',
  dataType: 'uint8',
})

const frameOutput = useFrameOutput({
  pixelFormat: 'yuv',
  onFrame(frame) {
    'worklet'
    if (objectDetection.state !== 'loaded' || resizer == null) {
      frame.dispose()
      return
    }

    // 2. Resize the Frame to the model's input size
    const resized = resizer.resize(frame)
    frame.dispose()
    const data = new Uint8Array(resized.getPixelBuffer())
    resized.dispose()

    // 3. Extract the exact slice of the underlying ArrayBuffer
    const inputBuffer = data.buffer.slice(
      data.byteOffset,
      data.byteOffset + data.byteLength
    )

    // 4. Run model with given input buffer synchronously
    const outputs = objectDetection.model.runSync([inputBuffer])

    // 5. Interpret outputs accordingly
    const detection_boxes = new Float32Array(outputs[0]!)
    const detection_classes = new Float32Array(outputs[1]!)
    const detection_scores = new Float32Array(outputs[2]!)
    const num_detections = new Float32Array(outputs[3]!)
    console.log(`Detected ${num_detections[0]} objects!`)
  },
})

return <Camera device="back" isActive={true} outputs={[frameOutput]} {...otherProps} />

[!NOTE] Unlike v4, VisionCamera v5 no longer requires boxing the model with NitroModules.box(). Since v5 is built on Nitro Modules and uses react-native-worklets, worklets can access HybridObjects like the TFLite model directly.

Using GPU Delegates

GPU Delegates offer faster, GPU-accelerated computation. There are multiple delegates available:

CoreML (iOS)

Expo

Use the config plugin in your expo config (app.json, app.config.json or app.config.js):

{
  "name": "my app",
  "plugins": [
    [
      "react-native-fast-tflite",
      {
        "enableCoreMLDelegate": true
      }
    ]
  ]
}

Bare React Native

1. Set $EnableCoreMLDelegate to true in your Podfile:

   $EnableCoreMLDelegate=true
   
   # rest of your podfile...
   

2. Open your iOS project in Xcode and add the CoreML framework under General → Frameworks, Libraries and Embedded Content.

3. Re-install Pods and build:

   cd ios && pod install && cd ..
   yarn ios
   

4. Use the CoreML Delegate:

   const model = await loadTensorflowModel(
     require('assets/my-model.tflite'),
     ['core-ml']
   )
   

[!NOTE] Not all model operations are supported on the CoreML delegate. Make sure your model is compatible.

Android GPU/NNAPI (Android)

To enable GPU or NNAPI on Android, you may need to include native libraries, especially on Android 12+.

Expo

Use the config plugin in your expo config (app.json, app.config.json or app.config.js) with enableAndroidGpuLibraries:

{
  "name": "my app",
  "plugins": [
    [
      "react-native-fast-tflite",
      {
        "enableAndroidGpuLibraries": true
      }
    ]
  ]
}

By default, when enabled, libOpenCL.so will be included in your AndroidManifest.xml. You can also include more libraries by passing an array:

{
  "name": "my app",
  "plugins": [
    [
      "react-native-fast-tflite",
      {
        "enableAndroidGpuLibraries": ["libOpenCL-pixel.so", "libGLES_mali.so"]
      }
    ]
  ]
}

[!NOTE] For Expo, remember to run prebuild if the library is not yet included in your AndroidManifest.xml.

Bare React Native

Add any needed entries to your AndroidManifest.xml:

<uses-native-library android:name="libOpenCL.so" android:required="false" />
<uses-native-library android:name="libOpenCL-pixel.so" android:required="false" />
<uses-native-library android:name="libGLES_mali.so" android:required="false" />
<uses-native-library android:name="libPVROCL.so" android:required="false" />

Then use the delegate:

const model = await loadTensorflowModel(
  require('assets/my-model.tflite'),
  ['android-gpu']
)
// or
const model = await loadTensorflowModel(
  require('assets/my-model.tflite'),
  ['nnapi']
)

[!WARNING] NNAPI is deprecated on Android 15. GPU delegate is preferred.

[!NOTE] Android does not officially support OpenCL, but most GPU vendors do.

Community Discord

Join the Margelo Community Discord to chat about react-native-fast-tflite or other Margelo libraries.

Adopting at scale

This library is provided as is, I work on it in my free time.

If you're integrating react-native-fast-tflite in a production app, consider funding this project and contact me to receive premium enterprise support, help with issues, prioritize bugfixes, request features, and more.

Contributing

1. Clone the repo
2. Make sure you have installed Xcode CLI tools such as gcc, cmake and python/python3. See the TensorFlow documentation on what you need exactly.
3. Run yarn bootstrap and select y on all iOS and Android related questions.
4. Open the example app and start developing
   • iOS: example/ios/TfliteExample.xcworkspace
   • Android: example/android

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

License

MIT