Javascript console.log() on HTC Android devices and adb logcat

In the default browser on Android 2.3.3 (and presumably from then on) you can simply use the built in javascript console:

• open the browser
• go to your webpage
• type about:debug in the address bar and hit enter
• you'll see a section for debug options appear if you go into the browser app's settings
• tick "Show JavaScript Console" if not already enabled
• refresh your webpage

At the top, you'll see a bar labeled "JavaScript Console".

I have been using three different HTC phones, almost exclusively, and have never had this issue. Here are a few things to check:

1. Make sure USB debugging is enabled.
2. Make sure your Webview has a WebChromeClient set. The browser used in Webview does not implement console.log().
3. It should be easy to see the output of adb logcat, but to make it easier, filter the output.

Turn on USB debugging:

1. Disconnect your device from your computer.
2. Go to Settings -> Applications -> Development -> Select "Enable USB Debugging"
3. Plugin to computer. (Make sure you have the correct drivers installed to use ADB - more info here: http://developer.android.com/guide/developing/device.html)

Set a WebChromeClient that overrides onConsoleMessage():

//Set the output prefix so you can filter adb logcat results laterpublic static final String TAG = "Your-Application-Name";myWebView = (WebView) findViewById(R.id.webview);//Not going to have much luck running JS without this:myWebView.getSettings().setJavaScriptEnabled(true);//Override onConsoleMessage() to output to the Log.myWebView.setWebChromeClient(new WebChromeClient() {    @Override    public boolean onConsoleMessage(ConsoleMessage cm) {        Log.d(TAG, cm.message() + " -- From line "        + cm.lineNumber() + " of "        + cm.sourceId() );        return true;    }});

More info on onConsoleMessage() here: http://developer.android.com/reference/android/webkit/WebChromeClient.html#onConsoleMessage(java.lang.String, int, java.lang.String)

More info on debugging in general here: http://developer.android.com/guide/webapps/debugging.html

Filter the output of adb logcat:

adb logcat tag-name:log-level *:S

tag-name matches the string specified in Log.xlog-level matches the log level you indicated when calling Log.x <---

Example relating to code above:

adb logcat Your-Application-Name:D *:S

This will show all d level logs for the matching tag, Your-Application-Name, and silence everything else.

More info on adb filtering here:http://developer.android.com/guide/developing/tools/adb.html#logcat

Hope it helps! I know it was a bit of summarizing of the other answers, but, the fact is, it takes all of the steps to make it work. :)

I had the same problem, I solve it by doing the following:

1/ when you initialize your webview, add a javascript bridge class:

appView.addJavascriptInterface(new JSBridge(), "JSBridge");

2/ create the class JSBridge with a log function

class JSBridge {  public void log(String msg){   Log.d(msg);  }}

3/ in your javascript you can now call

JSBridge.log("my log message");

Might be a bit overkill for your problem, but you can also do a LOT more with that solution