The robots.txt file lives at the root level of your domain, accessible at yourdomain.com/robots.txt. This location is standardized across all websites because search engine crawlers check this exact path when they first visit your site. If the file doesn't exist there, crawlers assume no restrictions apply and proceed to index everything they can access. On your server, the physical location depends on your hosting setup. For most shared hosting or cPanel environments, robots.txt goes in the public_html folder. WordPress sites typically place it in the same directory as wp-config.php and the wp-content folder. For Apache servers, that's usually /var/www/html or /var/www/yourdomain.com/public_html. If you're running Nginx, it's commonly /usr/share/nginx/html. You can check if your robots.txt exists by visiting yourdomain.com/robots.txt directly in a browser. If you see a 404 error, the file isn't present. Google Search Console also shows your current robots.txt under the Crawl section, and lets you test changes before deploying. Common mistakes we see: placing robots.txt in a subdirectory like /blog/robots.txt, which crawlers ignore completely. The file must be at the root. We also see clients accidentally blocking their entire site with "Disallow: /" when they meant to block a specific section, or forgetting to create the file on a new domain and wondering why Google isn't respecting their intended crawl rules that only exist in their head. At Ottawa SEO, we always verify robots.txt placement during technical audits because misplacement or misconfiguration causes immediate indexing problems. If you're managing multiple domains in a portfolio like we do, checking each robots.txt file is part of the monthly maintenance routine. The file is plain text, so you can edit it with any text editor, upload via FTP, or use your hosting control panel's file manager. Just remember: changes take effect immediately, so test carefully before saving.