# Debugging

> Use UniWebView's debugging tools, including the logger, web log forwarding, and web page inspection on iOS, Android, and macOS.

## UniWebView Logger

UniWebView could provide detail logs. It helps you to understand what happens in UniWebView.

There are 5 log levels, following the order of verbosity, they are:

- **Verbose**: The most detailed logging level. It prints out almost all events.
- **Debug**: Good for the general debugging purpose. It prints most of the events.
- **Info**: Fewer logs than Debug level, but will cover quite a few important events.
- **Critical**: This is the **default value** of the built-in logger. It only prints out error messages you need to notice.
- **Off**: Turning off the logger.

`UniWebViewLogger` class takes the responsibility to print log out to console on all platforms. You can set the log level by the code below:

```csharp
// Set the log level to Verbose
UniWebViewLogger.Instance.LogLevel = UniWebViewLogger.Level.Verbose;
```

The log message from UniWebView will start with a tag for each platform: `<UniWebView>`, `<UniWebView-iOS>`,
`<UniWebView-Android>`, `<UniWebView-macOS>`. It would be helpful if you want to search in your logs.

For more information on `UniWebViewLogger`, please refer to its [documentation](../api/uniwebviewlogger.md).

## Forwarding Web Logs to Unity

When it is necessary to confirm issues on the website, it may be required to check the web logs (such as through
JavaScript's `console.log` and other similar methods). UniWebView provides a convenient method to forward logs from the
web to Unity.

For performance and security reasons, this forwarding is turned off by default. To enable web log forwarding, you can
call `SetForwardWebConsoleToNativeOutput` before creating a web view:

```csharp
UniWebView.SetForwardWebConsoleToNativeOutput(true);

webView = webViewGO.AddComponent<UniWebView>();
webView.Load("https://your-website.com");
webView.Show();
```

> It is recommended to enable this feature only when necessary, and disable it when not needed.

## Inspecting Web Page

Sometimes, you need to inspect your web page, to modify some DOMs, stylesheets, or watching result of a JavaScript.
UniWebView supports to inspect your page in a browser dev tool in Chrome or Safari.

### iOS

On iOS, you need to call the [`SetWebContentsDebuggingEnabled`](/api/#setwebcontentsdebuggingenabled) method first. Then
you could just run and show your web page in UniWebView on an iOS device or simulator.

Follow the [Safari Web Inspector Guide](https://developer.apple.com/library/content/documentation/AppleApplications/Conceptual/Safari_Developer_Guide/GettingStarted/GettingStarted.html) to set up your inspector in Safari.

Please be noted, only binaries built with the Debug configuration can be inspected. The Release build does not work.

### Android

On Android, you need to call the [`SetWebContentsDebuggingEnabled`](/api/#setwebcontentsdebuggingenabled) method first.
It will allow Chrome to discover and connect to the web view on Android. Follow the
[Remote Debugging WebViews](https://developer.chrome.com/docs/devtools/remote-debugging/webviews/) topic to know how to
use Chrome DevTools with UniWebView.

### macOS

On macOS you need to call the [`SetWebContentsDebuggingEnabled`](/api/#setwebcontentsdebuggingenabled) method first.
Then you can right-click on the web view in macOS editor to bring up the context menu. Select the "Inspect Element" in
that menu.

![](/images/editor-inspector.png)

::: warning
Due to a memory bug under WebKit and Unity, it might crash your macOS Editor when you stop playing with an inspector
showing embedded in a web view. To avoid this, close the inspector first or use it as a standalone window. This issue
only happens in the editor and never affects real devices. Please remember to not enable the
`SetWebContentsDebuggingEnabled` in your product build. This feature should be only used in development.
:::