Browser console log capture in Selenium Python

Introduction

Capturing browser console logs helps find errors or warnings that happen on a webpage during testing.

When you want to check if any JavaScript errors appear on the page.

When you need to verify warnings or messages logged by the website.

When debugging why a page behaves unexpectedly during automated tests.

When tracking performance or security messages shown in the console.

When ensuring no unexpected errors occur after a user action.

Syntax

Selenium Python

logs = driver.get_log('browser')

This command fetches all browser console logs collected so far.

It returns a list of log entries, each with a message and level (e.g., SEVERE, WARNING).

Examples

Fetch and print all console log entries.

Selenium Python

logs = driver.get_log('browser')
for entry in logs:
    print(entry)

Filter and print only severe error messages from the console logs.

Selenium Python

error_logs = [log for log in driver.get_log('browser') if log['level'] == 'SEVERE']
print(error_logs)

Sample Program

This script opens a Chrome browser, navigates to example.com, captures all browser console logs, prints each log's level and message, then closes the browser.

Selenium Python

from selenium import webdriver
from selenium.webdriver.chrome.service import Service
from selenium.webdriver.chrome.options import Options

options = Options()
options.set_capability('goog:loggingPrefs', {'browser': 'ALL'})

service = Service()
driver = webdriver.Chrome(service=service, options=options)

try:
    driver.get('https://example.com')
    logs = driver.get_log('browser')
    for entry in logs:
        print(f"{entry['level']}: {entry['message']}")
finally:
    driver.quit()

Important Notes

Make sure to enable logging preferences in browser options before starting the driver.

Not all browsers support console log capture equally; Chrome is commonly used for this.

Logs may include info, warnings, and errors; filter as needed for your test goals.

Summary

Browser console log capture helps find hidden errors during tests.

Use driver.get_log('browser') to get logs.

Filter logs by level to focus on important messages.