Render as Texture

UniWebView allows rendering web content as a non-interactive texture in Unity, suitable for 3D integration but with performance and feature limitations.

Usually, UniWebView is used as a native overlay layer on top of the whole Unity scene. That means you cannot put any other Unity element on top of the web view (see the FAQ here). Instead, UniWebView provides a way to render the current web view content into a texture, you can use the texture in the 3D world, such as Unity RawImage or any Material on any 3D object.

LIMITATION

When rendered as texture, the web view will not be interactive anymore. Although it is still possible to call any method programmatically on the web view, you cannot click on any link or button, or scroll the web view by gesture. It is just a visual snapshot of the current web view content.

All hardware acceleration content, such as the video or WebGL elements, cannot be rendered.

See the Limitations section below for more details.

Here is what it looks like when you render the web view into a texture and put it on a cube:

Implementation

UniWebView provides StartSnapshotTextureStream for continuous render-as-texture use. The stream owns one live texture and updates it in place on supported platforms. Assign the texture once when the stream becomes ready, then dispose the stream during cleanup.

The older StartSnapshotForRendering, GetRenderedData, and CreateRenderedTexture APIs are still available for compatibility, but they are legacy. They use a PNG-backed snapshot path and CreateRenderedTexture creates a new standalone texture every time it is called.

Start a Texture Stream

Before you begin to use the texture, start a stream by calling the StartSnapshotTextureStream method.

public class MyBehaviour : MonoBehaviour {

  UniWebView webView;
  UniWebViewSnapshotTextureStream stream;
  Renderer cubeRenderer; // cube.GetComponent<Renderer>();

  void OpenWebView() {
    webView = gameObject.AddComponent<UniWebView>();
    webView.Frame = new Rect(0, 0, Screen.width, Screen.height);
    webView.Load("https://uniwebview.com");

    stream = webView.StartSnapshotTextureStream(onReady: texture => {
      cubeRenderer.material.mainTexture = texture;
    });
  }
}

It is no need to call Show method to actually display the web view. The stream can be started even if the web view is not visible.

The texture passed to onReady is owned by the stream and updated in place. Do not destroy and recreate it every frame. If onReady is not called and stream.IsReady remains false, the current platform or graphics backend does not support the optimized stream path. UniWebView does not silently fall back to the legacy PNG texture path.

On Android, the optimized native texture path requires OpenGL ES 2 or OpenGL ES 3. When Unity runs on another graphics API such as Vulkan (the default choice of Auto Graphics API on most devices), the stream automatically falls back to a CPU readback path: the captured frame data is copied into the stream-owned texture instead of being uploaded through the native OpenGL ES bridge. The stream behaves identically, but each frame costs an extra CPU copy and texture upload. Switch the Android graphics API to OpenGL ES if you need the best snapshot texture streaming performance.

If you still want to show the texture in a plain 2D format, then a the Unity's Plane or RawImage might be your choice.

Clean Work

Finally, when you no longer need the web view to generate any additional textures, dispose the stream. This closes the native stream and releases the stream-owned texture.

cubeRenderer.material.mainTexture = null;
stream?.Dispose();
stream = null;

When you destroy the web view (by either calling the Destroy on the UniWebView component or destroying the whole scene containing the web view), UniWebView will dispose the active stream for you. When you keep the best practice that is mentioned in the Memory Management guide, usually you do not need to call this method manually yourself.

Performance

It is heavy work to take snapshots of the web view and pass them between the native side and Unity, especially on old devices. There are some small tips to improve the performance.

Refresh Interval

By default, StartSnapshotTextureStream captures a new snapshot every frame for the best responsiveness. However, this can be expensive — especially on Android where snapshot capture runs on the main thread. You can pass a refreshInterval parameter to reduce the capture frequency:

// Capture at ~30 fps instead of every frame.
stream = webView.StartSnapshotTextureStream(refreshInterval: 1.0f / 30, onReady: texture => {
    cubeRenderer.material.mainTexture = texture;
});

// Capture at ~10 fps for a mostly-static page.
stream = webView.StartSnapshotTextureStream(refreshInterval: 1.0f / 10, onReady: texture => {
    cubeRenderer.material.mainTexture = texture;
});

With a refresh interval set, the stream scheduler requests native snapshots at the specified rate while keeping the same Unity texture object alive.

Resolution Scale

By default, the stream captures at the full resolution of the web view. On devices with a high display scale (such as recent iPhones with a 3x Retina screen), every frame produces a large image that has to be converted and uploaded. If the texture is displayed smaller than the web view, or a softer image is acceptable, pass a resolutionScale in the (0, 1] range to cut the per-frame cost roughly by the square of the scale:

// Capture at half resolution: ~1/4 of the pixel processing per frame.
stream = webView.StartSnapshotTextureStream(resolutionScale: 0.5f, onReady: texture => {
    cubeRenderer.material.mainTexture = texture;
});

The resolutionScale parameter currently takes effect on iOS and macOS. On Android, it is ignored and the stream always captures at full resolution.

TIP

The stream API avoids the legacy PNG encode/decode path on supported platforms. The legacy APIs remain source-compatible for existing projects, but they should not be used for new continuous texture rendering.

Start After Page Load

If the web content is static and does not change after the first load, instead of taking the snapshot in Update, you can start the stream in the OnPageFinished event:

public class MyBehaviour : MonoBehaviour {

  // ...

  void OpenWebView() {
    webView = gameObject.AddComponent<UniWebView>();
    webView.Frame = new Rect(0, 0, Screen.width, Screen.height);
    webView.Load("https://uniwebview.com");

    webView.OnPageFinished += (view, code, error) => {
      stream = webView.StartSnapshotTextureStream(onReady: texture => {
        cubeRenderer.material.mainTexture = texture;
      });
    };
  }
}

Size and Partial Snapshot

The size of the texture is also a factor that affects the performance. The larger the texture is, the more time it takes to be rendered and passed between native and Unity.

To only stream a partial snapshot of the web view, pass a Rect to StartSnapshotTextureStream:

// Take the snapshot of 100x100 square in the middle of the web view.
var rect = new Rect(webView.Frame.width / 2 - 50,  webView.Frame.height / 2 - 50, 100, 100);
stream = webView.StartSnapshotTextureStream(rect, onReady: texture => {
    cubeRenderer.material.mainTexture = texture;
});

The final pixel count of the snapshot matters. If you do not need the texture to be at the high resolution, you can also create a smaller web view from the very beginning, for example:
// webView.Frame = new Rect(0, 0, Screen.width, Screen.height);
webView.Frame = new Rect(0, 0, Screen.width / 4, Screen.height / 4);

Other Limitations

The rendered texture is not a native view but only a live snapshot stream of the view. There are some other limitations other than the performance.

Interaction

The rendered texture is not interactive. You cannot click any link or button on the texture, or scroll the web view by gesture.

Although the user interaction is not available, you can still call any UniWebView methods on the web view programmatically. It is also possible to use methods like ScrollTo to "simulate" the scrolling, or use JavaScript to "click" the button or link on the web page. For example, you can use the following code to get all links on the page, and click the first one:

webView.OnPageFinished += (view, statusCode, url) => {
    webView.EvaluateJavaScript("Array.from(document.links).map(link => link.href);", result => {
        var data = UniWebViewExternal.Json.Deserialize(result.data) as List<object>;
        // Use the data: ["https://example.com", "https://example.com/link1", ...]

    });
};

// Later, simulate the click on the first link.
webView.EvaluateJavaScript("document.links[0].click();");

Simulating a user tap on the native view is not possible through public APIs on iOS. So it won't be implemented in the current UniWebView. We are keeping an eye on the latest iOS system changes. If Apple provides a way to do it in iOS, we will try to support it too.

Video

Any hardware-accelerated content, such as video or WebGL elements, cannot be rendered. You will only see a black rectangle in the place of the video.

# Render as Texture

# Implementation

# Start a Texture Stream

# Clean Work

# Performance

# Refresh Interval

# Resolution Scale

# Start After Page Load

# Size and Partial Snapshot

# Other Limitations

# Interaction

# Video