Debugging Cordova Apps

Here's the good news: a Cordova app's UI is just HTML, CSS, and JavaScript rendered inside a WebView, which means you already own the single best tool for debugging it — the browser developer tools you've been using for ordinary websites all along. You don't need a specialized "Cordova debugger." What you do need is a way to point those familiar dev tools at the WebView running inside a real device or emulator, since that's the environment your users will actually experience, quirks and all. This page walks through remote debugging on Android via Chrome, remote debugging on iOS via Safari, the humble console.log(), falling back to native device logs, and a short guide to isolating plugin-specific problems.

Remote Debugging Android with Chrome DevTools

Since Cordova's Android WebView is (on modern devices) backed by Chromium, desktop Chrome can attach to it directly over a USB connection and give you the full DevTools experience — Elements, Console, Network, Sources with breakpoints, all of it — pointed at the exact WebView your app is running. The walkthrough:

Once that DevTools window is open, treat it exactly like inspecting any web page: set breakpoints in the Sources panel, watch network requests, inspect the live DOM, and read whatever your code prints to the console — all reflecting the actual app running on the actual device.

Remote Debugging iOS with Safari's Web Inspector

iOS uses the same idea through Safari instead of Chrome, though the setup requires a Mac (Xcode and Safari's developer tooling aren't available on Windows or Linux). In brief:

console.log() — Your Fastest Tool

Both remote debugging setups above surface anything your code writes with console.log() in the attached DevTools/Web Inspector console, which makes it the fastest way to sanity-check a value, confirm a callback actually fired, or trace how far execution got before something broke — often faster than setting a formal breakpoint.

document.addEventListener('deviceready', onDeviceReady, false);

function onDeviceReady() {
    console.log('deviceready fired, platform: ' + device.platform);

    navigator.camera.getPicture(onCameraSuccess, onCameraError, { quality: 75 });
}

function onCameraSuccess(imageData) {
    // If this never prints, the plugin callback isn't firing at all
    console.log('Camera success, data length: ' + imageData.length);
}

function onCameraError(message) {
    console.error('Camera error: ' + message);
}

Viewing Native Logs (adb logcat)

Sometimes a problem happens below the WebView entirely — a native crash, a plugin's native code throwing an exception, or the app failing to even reach the point where a WebView console exists. For Android, adb logcat reads the device's full native log stream and is your fallback when the Chrome DevTools inspector isn't enough (or the app crashed before you could attach it):

adb logcat

That firehose includes every process on the device, so it helps to filter it down to just your app's messages and Cordova's own tag:

adb logcat -s CordovaLog:V chromium:V AndroidRuntime:E

console.log() calls from your JavaScript are actually mirrored into logcat under the CordovaLog (or chromium) tag, so this same command doubles as a way to watch your JS console output without Chrome attached at all — handy for a quick check on a device that isn't near your development machine's USB port.

The "It Only Works in the Browser Platform" Gotcha

Cordova supports a browser platform that runs your www/ app directly in a desktop browser tab, which is genuinely convenient for rapid UI iteration — no build, no device, instant reload. The gotcha is that it's a WebView in name only: most Cordova core and community plugins either don't run there at all or fall back to browser-native stand-ins that behave differently from the real native plugin. A camera call might just open the desktop's file picker instead of the actual camera hardware, for example.

Debugging Plugin-Specific Issues

When a plugin misbehaves — a callback never fires, a method throws "undefined is not a function," or results look wrong — work through these checks roughly in order: