Robots.txt & Sitemap
Validator

Robots.txt is a text file stored in the root directory of a website, used to tell search engine crawlers (such as Googlebot) which pages can be crawled and which pages should not be crawled. When search engines want to index your site, they will first check /robots.txt Whether it exists, and the crawling behavior is determined based on the rules therein. It uses "User-agent" to specify the target crawler, and "Disallow" and "Allow" to control access permissions. It's important to note that robots.txt is a "gentleman's agreement" and not a security mechanism - malicious programs can still ignore these rules.

Sitemap.xml (sitemap) is an XML file that lists the URLs of all important pages on the website and can be appended lastmod(date of last modification),changefreq(update frequency) and priority(priority) and other metadata. For SEO, a sitemap helps search engines discover and index your pages faster, especially for new sites, large sites, or sites with infrequently updated content. Submitting a sitemap to Google Search Console can significantly improve the indexing efficiency of your website.

If robots.txt contains Disallow: /, meaning all paths are blocked, and search engines will not be able to crawl any pages on the website. This will result in: ① website pages disappearing from search results or not being indexed; ② included pages may be removed; ③ your website content cannot be seen in Google search results. It is strictly recommended to only use it temporarily under specific circumstances (such as during website maintenance), and be sure to match Allow: / Rules for fine control. If your site is being penalized by SEO or want to test, use noindex meta tag instead.

It is not necessary to include all pages, but it is recommended to include important pages that you want to be indexed by search engines. Google's specifications state that a single Sitemap file can contain up to 50,000 URLs and should not exceed a compressed size of 50MB. If your website exceeds this number, you need to use a Sitemap Index (index file) to compile multiple sub-Sitemaps into an index. Generally recommended: ① Prioritize the inclusion of high-quality, unique content pages; ② Exclude duplicate content such as tag pages, category pages, filter pages, etc.; ③ There is no need to include the management background or login page; ④ Update the sitemap regularly to reflect the latest content of the website.

Robots.txt and Sitemap are complementary SEO tools. Robots.txt controls "where crawlers shouldn't go", while Sitemap tells crawlers "where the important content is." The best practice is: ① Use in robots.txt Sitemap: The instruction points to the location of sitemap.xml, allowing the crawler to find the site map directly; ② Make sure that the sitemap does not contain URLs blocked by robots.txt (otherwise the crawler will first read robots.txt and find that it is banned, and then ignore the corresponding URL in the sitemap); ③ Use robots.txt to protect sensitive areas (administration backend, temporary archives, etc.), and use sitemap to submit high-quality content. Use the two together to maximize the crawling efficiency of search engines.

You can check through the following methods: ① Visit directly in the browser https://你的網域/robots.txt and https://你的網域/sitemap.xml View the original content; ② Use the "Paste Content" mode of this tool to paste the content and analyze it; ③ Use Google Search Console's "Page Index" and "Sitemaps" reports to view the official detection results; ④ Use Google's "Robots Testing Tool" to test whether a specific URL is blocked. This tool provides offline and real-time checking methods without worrying about data leakage.

These tags are helpful for SEO: ① lastmod(Last modified date) - Google will refer to this date to determine whether the page has been updated, which is especially important for news or frequently updated websites; ② changefreq(Update frequency) - indicates how often the page may change, but Google states that this label is only for reference, and the actual crawl frequency is determined by the algorithm; ③ priority(Priority 0.0-1.0) – Indicates the importance of the page relative to other pages on the site. Google officially states that priority and changefreq are no longer ranking signals, but filling in lastmod correctly will still help crawlers crawl your website more effectively.