SEO Bookmarklets: Checker v2.0

Essentially, these are just bookmarks that allow you to quickly check the parameters of a domain or the current page that is open in the browser at the time you click on the bookmark. No unnecessary clicks, URL copying, or pasting. Saves a lot of time if you have to do this often.

• SSL (check)

  Test

  Code

  A page with certificate verification data will immediately open. It shows whether the certificate exists and whether it is installed correctly. By the way, if the expiration date is red because it will expire soon, then most likely it’s just auto-renewal and there is no reason to panic.

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• TLS (check version)

  Here you can’t open the results right away, but the domain will already be automatically copied to the clipboard - all you have to do is paste it into the field and run the check.

  Test

  Code

  Checked only if you have an SSL certificate. Make sure the server supports TLS version 1.3

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• HSTS (check)

  Test

  Code

  If you have an SSL certificate and the latest version of TLS, you also need to configure the correct HSTS header and add the site to the preload list. This reduces page load time by eliminating server redirects from HTTP to HTTPS.

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• 304 Not Modified (images)

  Here you need to check not the page itself, but any static file (image, script, style). The link to the image will already be copied to the clipboard - all that remains is to paste it and run the check.

  Test (copies the image URL only on the page where it runs)

  It works like a bookmarklet, but if you have specified a link at the top for a one-time check of another site, then it will go to the check site, but for the test you will have to independently look for a link to the static file of that site.

  Code

  I have detailed but not long video about Last-Modified and Not-Modified, with a description of the error and instructions for fixing it.

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• Mobile-Friendly (Google Tools)

  Test

  Code

  Checking page optimization for mobile devices.

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• Server response code (bertal.ru)

  Test

  Code

  Full list of server response codes. I mainly use the tool to make sure that the desired page returns 200, and a non-existent page returns 404.

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• 301 redirect to the main mirror (check in Yandex.Webmaster)

  To check, you need to be registered with Yandex Webmaster.

  Test

  Code

  The page is checked, but with a substitution of the protocol and subdomain. The result of the check must be 301 HTTP status code, and the “Location” field must contain the main address with the correct protocol and reverse substitution of the www prefix.

  In other words, if you click on the link in the “Location” item, another check will occur, which should show the code 200, and not again 301.

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• Redirects (checking the entire chain)

  Works like the previous bookmarklet, but shows the entire chain of redirects at once.

  Test

  Code

  There should be only one 301 code in the chain, and then 200 at once.

  Sometimes there are sites with double or even triple redirection - first only to https, then redirected using the www prefix, but for some reason to the http protocol, and then again to https (this should not happen).

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• robots.txt (view)

  Test

  Code

  Often it is necessary to simply visually look at the robots.txt file, and this bookmarklet saves me time.

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• robots.txt (check in Yandex.Webmaster)

  To check, you need to be registered with Yandex Webmaster.

  Test

  Code

  After the transition, all fields will be filled in, but you need to manually start checking the file first, and then checking the page URL for blocking in the robots.txt file

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• sitemap.xml (view)

  Test

  Code

  To quickly navigate to an XML sitemap using a standard address. If you couldn’t open it, that doesn’t mean it doesn’t exist—sometimes the Sitemap is located at a different link. You can see the correct link in the robots.txt file.

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• sitemap.xml (check in Yandex.Webmaster)

  To check, you need to be registered with Yandex Webmaster.

  Test

  Code

  Well, here the standard map URL is checked. If it is different, then you will have to kill it manually.

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• 404 (view)

  Test

  Code

  The page should not create the impression that the entire site does not work at all - easy design to match the site design.

  The page should not be intimidating - you need a thematic picture and explanatory text.

  It should be possible to return to viewing the site - to the main page or directly to the desired section of the catalog.

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• 404 (check code in Yandex.Webmaster)

  To check, you need to be registered with Yandex Webmaster.

  Test

  Code

  The main task here is to make sure that the HTTP status code = 404 Not Found

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• HTML validator (check for errors)

  Test

  Code

  Serious errors include unclosed quotes and tags. There is also a “Fatal Error” after which the validator cannot even understand the rest of the code (so look for “Fatal Error” at the very end of the list).

  There are two super light warnings in the screenshot that the role for the header and footer does not need to be specified - I do not agree with this.

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• CSS validator (check for errors)

  Test

  Code

  There are parsing errors that can negatively affect promotion. And in general, I am for clean code without errors.

  By the way, I have YouTube has a video on this matter... and on many other items on this list.

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• Schema.org validator (check markup)

  Test

  Code

  In addition to checking for errors in markup, make sure that everything that can be marked up is marked up. Don’t forget that in the validator you can click on the markup items and see the details. Within one markup, others can be nested.

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• Schema.org (snippets)

  Test

  Code

  Check the markup of items that can be shown as rich search results.

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• Open Graph (check)

  Sometimes the test is buggy and you need to refresh the page.

  Test

  Code

  There are many other resources, but this is something that has happened lately and the test does not pass right away and the design jumps with large images in the Open Graph markup. Nevertheless, this is my favorite resource, as it shows not only data, but also errors. And there you can make a clear screenshot for the client and for the portfolio BEFORE/AFTER.

  P.S.: Markup is used not only for social networks, but also in messengers, forums and other places where you share links to your site.

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• Favicon (check)

  Test

  Code

  The bookmarklet takes you to a resource with a clear check of all Favicon options. It only does not check for the presence of an SVG version of the icon.

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• Viruses (Google check)

  Test

  Code

  The site can become infected with viruses as a result of hacking weak passwords, from the computer of an unreliable programmer, etc. I am for a safe Internet and do not start optimizing a site while there are viruses on it.

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• Viruses (Dr.WEB scan)

  Here you can’t open the results right away, but the link will already be automatically copied to the clipboard - all you have to do is paste it and run the check.

  Test

  Code

  I trust this antivirus, since I have been using it for 15 years. There were no problems during this time - this is a very reliable indicator.

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• Viruses (check comprehensively)

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  Code

  Not long ago I found this resource. Now I use it regularly. I haven’t encountered any sites with problems yet, so I don’t know all the functionality and reliability of the information. That is why I still use the two previous bookmarklets with verification in Google and Dr.WEB

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• PageSpeed ​​Insights (check speed)

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  Code

  I think everyone knows this resource. But I’ll explain anyway. All its value is not in the beautiful information that is in the screenshot, but in the points from the “Optimization” and “Diagnostics” sections, which are located below. You can click on items to reveal detailed information.

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• WebPageTest (check speed)

  After going to the resource, the required URL will already be indicated in the field. You just need to click the “Start Test” button

  Test

  Code

  If you figure it out and get used to it, this resource is much cooler than PageSpeed ​​Insights.

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• PING the site (check server response speed)

  The URL, as usual, is automatically copied to the buffer, and on the site you will need to paste it, select the desired city (or several) and run the check.

  Test

  Code

  A convenient tool from a cool specialist Anton Belogorodtseva.

  You can check several sites from several cities at once. To get a normal result you need to wait. Let the site run in the background for a couple of minutes.

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• HTTP/2 protocol (check)

  The link to the page being checked will already be copied. All that remains is to insert and run the check.

  Test

  Code

  The server connection protocol has been HTTP/3 for a long time, but some still use HTTP/1.1, and there should be a minimum of HTTP/2.

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• HTTP/3 protocol (check)

  The required link will already be copied. Paste and run the test.

  Test

  Code

  Soon we will all be using it, but for now it does not yet have any special advantages over HTTP/2

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• Gzip/Brotli compression (check)

  After the transition, paste the link and click “Test URL”.

  Test

  Code

  Brotli is better, but it all depends on your hosting and system administrator. The main thing is that there is at least Gzip.

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• CSS optimization (check)

  The link is copied automatically. After the transition, just paste it and click “Test Page”.

  Test

  Code

  It’s not entirely clear what specific pieces of code and styles are mentioned in the post-test reporting, but this is the most detailed CSS checker I’ve ever come across.

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• h1-h6, strong, b, em, i (highlight)

  Click again to remove highlighting of elements

  Test (highlights elements only on the page where it runs)

  It works as a bookmarklet, but it will not run against another URL entered in the field above.

  Code

  <‍strong><‍/strong> - used only to highlight an entire phrase in a paragraph. Not used to highlight one word or some unfinished semantic expression. Used <‍strong>only to highlight the main idea<‍/strong> from the general array. Minimum for two words. With such selections, you can build the structure of the main phrases for promotion to the TOP. You can get manual sanctions if you mindlessly spam this tag on a page.

  <‍b><‍/b> - used for highlighting <‍b>key<‍/b> words Maximum for two. We highlight what is a significant key for the page or for the site as a whole. According to all the rules <‍b>semantic layout<‍/b>, the b tag is not used for phrases.

  <‍em><‍/em> - serves to emphasize and emphasize a word or phrase. For example:
  - Who said that?
  — <‍em>I<‍/em> said so.
  - You said differently.
  - I <‍em>said so<‍/em>.

  <‍i><‍/i> - NOT used to add icons like <‍i class="fa fa-check"><‍/i>, this is a semantic tag for technical terms, foreign and other words that stand out from regular text. Use it correctly, and <‍i>everything will be fine<‍/i>.

  All these and similar tags are not intended for text formatting!
  NOT for design!
  They are not for creating italic or bold text. They carry a certain semantic meaning, and the fact that they change the style of the text is a relic of the past to support old technologies. If you need to make it bold or italic, use styles and frame it with a tag span.

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• Structure h1-h6, IMG alt/title, etc. (coolBm v2.0)

  Lists can be viewed by clicking on the items (see screenshot).

  Test (reads data only on the page where it runs)

  It works as a bookmarklet, but it will not run against another URL entered in the field above.

  Code

  Bookmarklet from Alexander Arsenkin has a lot of useful information, but I like it because you can quickly see the hierarchy of headings indicating errors, and you can also quickly see how the alt attributes of the pictures are written. Lacks error output when alt is missing.

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• Alt instead of images

  Clicking again removes the highlighting of ALT texts and returns the pictures.

  Test (shows ALT only on the page where it runs)

  It works as a bookmarklet, but it will not run against another URL entered in the field above.

  Code

  It’s very convenient to see how organically the alt fits into the surrounding text. I took the bookmarklet from M. Shakin’s course, but modified the highlighting and explanation so that pictures that do not have an alt attribute or are empty are clearly visible (see screenshot).

  How to write the alt attribute for images and when you can leave it empty is a whole separate big story. Here is good clear documentation (with standard translation in the browser you can easily figure it out).

  P.S.: If after clicking on the bookmarklet you still see pictures, then they are inserted into the site with styles as background images and are NOT indexed.

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