If you are using Responsive Web Design, use meta name="viewport" tag to tell the browser how to adjust the content. If you use Dynamic Serving, use the Vary HTTP header to signal your changes depending on the user-agent. If you are using separate URLs, signal the relationship between two URLs by tag with rel="canonical" and rel="alternate" elements.
Crawlers are largely a separate product category. There is some overlap with the self-service keyword tools (Ahrefs, for instance, does both), but crawling is another important piece of the puzzle. We tested several tools with these capabilities either as their express purpose or as features within a larger platform. Ahrefs, DeepCrawl, Majestic, and LinkResearchTools are all primarily focused on crawling and backlink tracking, the inbound links coming to your site from another website. Moz Pro, SpyFu, SEMrush, and AWR Cloud all include domain crawling or backlink tracking features as part of their SEO arsenals.
That's why PA and DA metrics often vary from tool to tool. Each ad hoc keyword tool we tested came up with slightly different numbers based on what they're pulling from Google and other sources, and how they're doing the calculating. The shortcoming of PA and DA is that, even though they give you a sense of how authoritative a page might be in the eyes of Google, they don't tell you how easy or difficult it will be to position it for a particular keyword. This difficulty is why a third, newer metric is beginning to emerge among the self-service SEO players: difficulty scores.
The basics of GOOD SEO hasn’t changed for years – though effectiveness of particular elements has certainly narrowed or changed in type of usefulness – you should still be focusing on building a simple site using VERY simple SEO best practices – don’t sweat the small stuff, while all-the-time paying attention to the important stuff – add plenty of unique PAGE TITLES and plenty of new ORIGINAL CONTENT. Understand how Google SEES your website. CRAWL it, like Google does, with (for example) Screaming Frog SEO spider, and fix malformed links or things that result in server errors (500), broken links (400+) and unnecessary redirects (300+). Each page you want in Google should serve a 200 OK header message.
For example, within the HubSpot Blogging App, users will find as-you-type SEO suggestions. This helpful inclusion serves as a checklist for content creators of all skill levels. HubSpot customers also have access to the Page Performance App, Sources Report, and the Keyword App. The HubSpot Marketing Platform will provide you with the tools you need to research keywords, monitor their performance, track organic search growth, and diagnose pages that may not be fully optimized.
You can confer some of your site's reputation to another site when your site links to it. Sometimes users can take advantage of this by adding links to their own site in your comment sections or message boards. Or sometimes you might mention a site in a negative way and don't want to confer any of your reputation upon it. For example, imagine that you're writing a blog post on the topic of comment spamming and you want to call out a site that recently comment spammed your blog. You want to warn others of the site, so you include the link to it in your content; however, you certainly don't want to give the site some of your reputation from your link. This would be a good time to use nofollow.