What is a 301 redirect?
A plain-English explanation of the 301 permanent redirect: what it does, when to use it, how to set one up and how to confirm it works.
Guides
Practical, step-by-step website launch and SEO health guides.
Categories: All (247)
Showing 169 to 192 of 247 guides (page 8 of 11)
What is a canonical tag?
A canonical tag tells search engines which URL is the main version of a page. See what it looks like, where it goes and how to avoid common errors.
What is a CDN and do I need one?
A CDN serves copies of your files from servers near visitors. Find out what it does, who benefits most and how to tell whether your site needs one.
What is a Content-Security-Policy header?
A Content-Security-Policy header tells browsers which sources a page may load code and files from. See the main directives and how to roll one out safely.
What is a redirect chain and why is it bad?
A redirect chain sends visitors through several redirects before the final page. See why it slows pages and wastes crawling, and how to flatten it.
What is a sitemap index file?
A sitemap index file points to several sitemaps so a large site stays within size limits. See the format, an example and how to submit it.
What is a soft 404?
A soft 404 is a page that looks missing or empty but returns a success code. Learn how to spot soft 404s and fix them with the right status code.
What is alt text and how do I write it?
Alt text is a short written description of an image for people who cannot see it. Learn what to write, when to leave it empty and how to check your images.
What is an SPF record?
Understand what an SPF record is, how receiving servers use it to check who may send mail for your domain, and how to read each part of one.
What is Article schema?
Article schema is structured data that names a page's headline, author, images and dates. Learn the types, the useful properties and how to add it.
What is breadcrumb structured data?
Breadcrumb structured data describes where a page sits in your site, from the home page down. See the BreadcrumbList format, an example and how to test it.
What is crawl budget?
Crawl budget is how many pages Googlebot will fetch from your site. Find out who needs to care, how to see your crawl activity and what wastes it.
What is DKIM?
Learn how DKIM signs outgoing email with a private key, how receivers check it against a DNS record, and how to confirm that your own signing works.
What is DMARC alignment (adkim and aspf)?
Understand DMARC alignment: how the SPF and DKIM domains must match your From domain, what relaxed and strict mean, and how adkim and aspf set it.
What is DMARC?
Learn what DMARC is, how it builds on SPF and DKIM to stop others spoofing your domain, and how to publish a first monitoring record safely.
What is duplicate content and does Google penalize it?
Learn what counts as duplicate content, why Google usually does not penalize it, and how to reduce duplicates with redirects, canonicals and unique text.
What is FAQ schema and does it still show in Google?
FAQ schema marks up questions and answers with FAQPage structured data. See what changed in Google Search, what it still does, and whether to keep it.
What is field data in Core Web Vitals (CrUX)?
Field data is performance measured on real visitors' devices and collected in the Chrome User Experience Report. See where to find it and its limits.
What is hreflang?
Hreflang tells Google which language or regional version of a page to show to which searchers. Learn the format, the rules and the common mistakes to avoid.
What is HSTS?
HSTS is a response header that tells browsers to use only HTTPS for your site. See an example, safe starting values and the preload risks to avoid.
What is INP in Core Web Vitals?
Interaction to Next Paint measures how quickly a page reacts to taps, clicks and key presses. Learn the 200 ms target and how to find slow interactions.
What is JSON-LD?
JSON-LD is the format Google recommends for structured data. See what it is, how a small block looks, where it goes on a page and how to test it.
What is lazy loading and when should I use it?
Lazy loading delays images and frames until they are close to view. See when it helps, when it hurts your main image and how to add it correctly.
What is LCP in Core Web Vitals?
Largest Contentful Paint times how long the main content takes to appear. See the 2.5 second target, what element counts and where to measure it.