Browser console logs live in Developer Tools. Press F12 in Chrome, Firefox, Edge, or Safari, then click the Console tab. Alternatively, right-click anywhere on a page, select Inspect or Inspect Element, and navigate to Console. This shows JavaScript errors, warnings, console.log() outputs, and network request issues that affect how your page renders or tracks user behavior. For server-side console logs, the location depends on your hosting setup. cPanel and Plesk usually have error log viewers under Metrics or Logs sections. If you're running a VPS or dedicated server, SSH in and check /var/log/apache2/ or /var/log/nginx/ for web server logs, or your application's specific log directory (like /var/www/yoursite/logs/). Node.js apps often output to terminal or PM2 logs. WordPress installs can enable WP_DEBUG_LOG in wp-config.php to write PHP errors to /wp-content/debug.log. At Ottawa SEO, we check browser console logs first when diagnosing Google Analytics tracking failures, GTM container issues, or broken JavaScript that blocks conversion pixels. A single console error can silently kill your entire tracking stack. Server logs matter when investigating 404 errors that hurt crawl budget, identifying bot traffic patterns, or debugging redirect chains that dilute link equity. Common mistakes: forgetting to clear cache before checking logs, ignoring warning-level messages that compound into real problems, and not filtering console noise on heavy JavaScript sites. Use the filter box in DevTools to search for specific scripts like gtag or fbevents. For production sites, never leave console.log() statements in your code because they slow execution and expose logic to competitors. Strip them during your build process or use environment flags to disable logging in production while keeping it active in staging.