Quick answers about websites, SEO and email
Short, direct answers to the questions site owners ask most: redirects and www, sitemaps and indexing, DMARC and email delivery, Core Web Vitals, structured data and images. Each answer starts with the short version, then shows how to do it and what to avoid. For the long step-by-step versions, see the guides.
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301 vs 302 redirect: what is the difference?
Learn when to use a 301 permanent redirect and when a 302 temporary redirect fits, how Google treats each one, and how to check which you have.
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404 vs 410: which should a removed page return?
Compare the 404 Not Found and 410 Gone status codes for deleted pages, see how Google treats each and choose the right one for your situation.
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Brotli vs gzip compression
Brotli usually produces smaller files than gzip. Learn when to use each, how browsers choose and how to confirm compression is working on your site.
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Canonical tag vs 301 redirect: which should I use?
Decide between a canonical tag and a 301 redirect for duplicate or moved pages, with a simple rule of thumb and examples for each situation.
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DMARC p=none vs p=quarantine vs p=reject
Compare the three DMARC policies, see what each asks receivers to do with failing mail, and learn the order to move from monitoring to enforcement.
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Do URL parameters hurt SEO?
URL parameters like ?sort= and ?utm_source= can create duplicate pages and waste crawling. Learn when they matter and how to keep them under control.
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Does lastmod in a sitemap matter?
Learn when the lastmod date in a sitemap helps Google, why priority and changefreq are ignored, and how to set accurate dates on your pages.
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How do I change my domain name without losing SEO?
Move to a new domain safely with page-to-page 301 redirects, the Search Console Change of Address tool and a checklist for before and after the switch.
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How do I check if a page is indexed by Google?
Use URL Inspection, the Page indexing report or a site: search to see whether Google has indexed a page, and learn what each result tells you.
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How do I check if my mail server is on a blocklist?
Find your sending IP, look it up on blocklist operators' own lookup pages, read bounce messages for clues, and know what to do if you are listed.
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How do I check if my website is accessible?
Check website accessibility with an automated scan plus a short manual test: keyboard, zoom, contrast, alt text and labels. Learn what each test can miss.
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How do I check my DMARC record?
Look up your DMARC record with dig or nslookup, read what each tag says, and confirm with a test email that DMARC is passing for your domain.
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How do I fix 'SPF: too many DNS lookups'?
Fix the SPF permerror caused by more than 10 DNS lookups: how to count them, which mechanisms cost a lookup, and safe ways to bring the total down.
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How do I fix \"Blocked by robots.txt\"?
Find the robots.txt rule that blocks a page in Search Console, change it safely and retest. Also covers when a block is the right choice.
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How do I fix \"Couldn't fetch\" for my sitemap?
Work through the checks that fix the Search Console sitemap status \"Couldn't fetch\": address, status code, redirects, firewalls and server logs.
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How do I fix \"too many redirects\"?
Find the cause of the ERR_TOO_MANY_REDIRECTS browser error, from HTTPS settings and www rules to cookies and plugins, and fix the loop step by step.
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How do I load web fonts without layout shift?
Stop text from jumping when a web font arrives. Preload the key font file, set font-display and match a fallback font so the swap barely moves.
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How do I make a good custom 404 page?
Build a custom 404 page that helps lost visitors, keeps your branding and returns a true 404 status, with server examples and a short checklist.
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How do I redirect non-www to www?
Copy-ready 301 redirect rules for Apache, nginx and ASP.NET Core that send example.com to www.example.com, plus the checks that prove it works.
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How do I redirect www to non-www?
Set up a permanent 301 redirect from www.example.com to example.com in Apache, nginx or ASP.NET Core, and test it so no URL ends up in a loop.
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How do I remove a page from Google search?
Remove a page from Google results using the Removals tool for a quick hide and noindex, a 404 or a password for a lasting fix, with clear steps.
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How do I remove URLs containing /post/ from Google (inurl:post)?
inurl:post finds pages but does not remove them. Learn to remove a whole folder with the prefix option in Search Console and fix it for good.
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How do I request indexing in Google Search Console?
Ask Google to crawl a new or updated page with the URL Inspection tool. Step-by-step instructions, the limits to expect and when not to bother.
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How do I speed up a slow website?
A practical order of work for a slow site: measure first, shrink images, compress text, cache files, cut scripts and check the server response.
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How do I submit a sitemap to Google?
Submit your sitemap in Google Search Console in a few steps, add it to robots.txt as a backup, and read the status that comes back.
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How do I test if my site supports HTTP/3?
Check HTTP/3 with browser DevTools, the Alt-Svc header, curl or an online checker, and learn why a first load can still show HTTP/2.
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How do I use the Rich Results Test?
Step-by-step use of Google's Rich Results Test: test a live URL or pasted code, read errors and warnings, and know what a pass does and does not mean.
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How do I verify my site in Google Search Console?
Prove you own your site in Google Search Console using a DNS record, an HTML file, a meta tag or an analytics connection, and keep the proof in place.
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How long does a DMARC change take to work?
A new or edited DMARC record takes effect as DNS caches expire, but reports and a safe rollout take weeks. See what to expect and how to check progress.
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How long does Google take to index a new page?
There is no fixed time for Google to index a new page. See what affects the wait, how to check progress and which steps help Google find your page.
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How long should a meta description be?
Google sets no meta description length limit. Learn a practical range, why snippets get rewritten and how to write a description people want to click.
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How long should a title tag be?
Google sets no fixed title tag limit, but long titles get cut off. Learn the practical length range, how pixel width works and how to write a clear title.
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How many H1 tags should a page have?
One H1 per page is the clearest choice for readers and screen readers. Learn what Google says about multiple H1s and how to fix a page that has none.
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How to create a sitemap.xml file
Create a sitemap.xml that lists your canonical pages, publish it at your site root and tell Google where it is. Includes a copy-ready example file.
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HTTP/2 vs HTTP/3: what should I enable on my CDN?
Enable both. HTTP/2 is the dependable base and HTTP/3 adds QUIC for lossy networks. Learn how browsers pick one, and what to check after switching.
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JSON-LD vs Microdata: which should I use?
Learn the difference between JSON-LD and Microdata structured data, why Google recommends JSON-LD, and when Microdata is still a reasonable choice.
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Lighthouse score vs real user data: which matters?
Lighthouse tests one simulated page load, while real user data records actual visits. Learn how to use each one and which to trust for decisions.
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noindex vs Disallow: what is the difference?
Disallow stops crawling and noindex stops listing in search. Learn which to use, why combining them fails and how to apply each correctly.
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Should URLs be lowercase?
Yes, keep URLs lowercase. Find out why uppercase letters create duplicate pages and how to redirect mixed-case URLs to a single lowercase form.
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Subdomain or subfolder for SEO?
Compare subdomains and subfolders for a blog, shop or help centre, and see which fits your setup, tracking and maintenance needs best.
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Trailing slash or no trailing slash on URLs?
Should your URLs end with a slash? Learn how Google treats both forms, how to choose one and how to redirect and canonicalize the other.
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WebP vs JPEG vs PNG: which format is best?
Compare WebP, JPEG and PNG for website images: when each fits, how they differ on quality, transparency and size, and how to switch safely.
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What are caching headers (Cache-Control)?
Cache-Control tells browsers and CDNs how long to keep a file. See the common values, a safe setup for pages and assets and how to check them.
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What are good Core Web Vitals scores?
The target numbers for LCP, INP and CLS, how the 75th percentile rule works and what Needs improvement and Poor mean, in one short reference page.
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What are Open Graph tags?
Open Graph tags are meta tags that set the title, description and image shown when your page is shared on social sites and in chat apps. See the main tags.
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What are render-blocking resources?
Render-blocking resources are CSS and JavaScript files that stop a page from showing anything until they load. Learn how to spot and unblock them.
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What causes layout shift (CLS)?
The usual culprits behind a poor CLS score: images without sizes, late embeds, injected banners, web fonts and animations. Learn how to spot each one.
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What do Google and Yahoo require from bulk email senders?
A plain summary of the Google and Yahoo bulk sender rules: SPF, DKIM, DMARC, one-click unsubscribe and spam complaint limits, with where to confirm them.
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What does 'p 0' in DMARC mean?
Find out why p=0 is not a valid DMARC value, what people usually mean by it, and how to correct the record using p=none or pct=0 correctly.
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What does a correct DMARC record look like?
See copy-ready DMARC record examples for monitoring, gradual enforcement and full reject, with the syntax rules that make a record valid.
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What does a noindex tag do?
A noindex tag asks search engines to leave a page out of results. See how to add it, how to confirm it works and the mistakes that break it.
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What does pct= mean in a DMARC record (and what is pct=0)?
Learn how the DMARC pct= tag works, why it defaults to 100, what pct=0 asks receivers to do, and how to use it to roll out enforcement gradually.
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What does rua= mean in a DMARC record?
Find out what the rua= tag does in a DMARC record, what an aggregate report contains, how to write the mailto: address and send reports elsewhere.
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What does ruf= mean in a DMARC record?
Understand the ruf= tag in a DMARC record, how failure reports differ from rua summaries, the fo option, and why many receivers never send them.
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What does \"Crawled, currently not indexed\" mean?
Googlebot has visited the page but not added it to search. See what the status means, the likely reasons and what to improve before you wait.
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What does \"Discovered, currently not indexed\" mean?
Google knows the page exists but has not crawled it yet. Learn why that happens and which site changes make a crawl more likely.
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What does \"Sitemap could not be read\" mean?
Understand the Search Console status \"Sitemap could not be read\", the usual causes behind it and the checks that show which one applies to your file.
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What file size should website images be?
There is no official image file size limit. Get practical size ranges for hero, article and thumbnail images, plus the steps that shrink a heavy picture.
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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.
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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.
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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.
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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.
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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.
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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.
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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.
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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.
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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.
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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.
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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.
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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.
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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.
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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.
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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.
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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.
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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.
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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.
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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.
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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.
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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.
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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.
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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.
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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.
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What is mixed content and how do I fix it?
Mixed content happens when an HTTPS page loads images, scripts or styles over HTTP. See why browsers block it and how to find and fix every case.
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What is MTA-STS?
Learn what MTA-STS is, how a DNS record and a policy file make other mail servers use encrypted TLS when sending to you, and how to roll it out safely.
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What is Organization schema?
Organization schema tells search engines your business name, website, logo and official profiles. See the key properties, an example and where to put it.
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What is reverse DNS (PTR) and why does email need it?
Learn what a reverse DNS PTR record is, why mail servers check it on the sending IP, and how to test and request one for your own mail server.
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What is robots.txt?
robots.txt is a small text file that tells crawlers which parts of a site they may visit. See what goes in it, a working example and common pitfalls.
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What is the best JSON-LD testing tool?
Compare Google's Rich Results Test with the Schema Markup Validator, see which to run first, and learn how to read errors and warnings in your JSON-LD.
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What is the sitemap size limit?
A sitemap file may hold 50,000 URLs and 50 MB uncompressed. See how to count yours and what to do when a site grows past either limit.
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What is the sp= tag in DMARC?
Learn how the DMARC sp= tag sets a separate policy for subdomains, when it is inherited from p=, and how to protect domains that never send mail.
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What is the viewport meta tag?
The viewport meta tag tells phones how wide to make your page. See the standard tag, what each part means and why you should not block pinch zoom.
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What is TLS-RPT?
Understand TLS-RPT, the DNS record that asks other mail servers to report TLS delivery failures to you, and how it works alongside MTA-STS.
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What is TTFB and what is a good value?
Time to First Byte is how long a browser waits for the first piece of a response. See the 0.8 second target, what slows it down and how to measure it.
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What replaced FID in Core Web Vitals?
Interaction to Next Paint took over from First Input Delay in March 2024. See what changed, why Google switched and what to measure on your site now.
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Where is my sitemap.xml?
Find the address of your sitemap.xml with five quick checks: the default path, robots.txt, Search Console, common plugin names and your CMS settings.
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Why are my images not loading (broken images)?
Find out why website images show as broken: wrong paths, deleted files, blocked requests and mixed content. Follow a quick check to find and fix the cause.
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Why do my website emails go to spam?
The usual reasons contact form and order emails land in spam, from missing SPF, DKIM and DMARC to blocklisted IPs, and how to test and fix each one.
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Why is my LCP slow?
Slow Largest Contentful Paint usually comes from one of four delays. Find which part of your load is the longest and fix that part first.
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WWW or no WWW for my website?
Not sure whether your website address should start with www? Use this short checklist to choose, set the redirect and keep one consistent address.
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WWW vs non-WWW: which is better?
Compare www and non-www addresses for search, DNS, cookies and CDNs, then learn how to pick one version and redirect the other without splitting your site.
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