Technical SEO: what’s included in technical optimization and where to start

What technical SEO consists of

The table below describes eight components: what exactly is checked in each one, why it matters, and where to read more. For three of them — server response codes, page speed, and the mobile version with HTTPS — there’s no dedicated deep-dive on the blog yet, so only the key facts and threshold values from the search engines’ documentation are given here, without a detailed practical guide.

Component	What’s checked	Why it matters	Where to read more
Crawler access	Which sections of the site are allowed to be crawled	If a crawler can’t load a page, it won’t make it into the index	The robots.txt file
Indexing	Which pages Google and Yandex have added to their index, and why	A page that isn’t in the index can’t appear in search	Site indexing
Duplicates and the canonical address	Whether the same page has more than one address	If a page has several copies, ranking signals get split between them	Canonical tags and duplicate pages
Sitemap	A file listing pages for search engine crawlers	On large and new sites, a sitemap helps a crawler find pages more efficiently, though it doesn’t guarantee they’ll all be crawled and indexed	Sitemap.xml
Structured data	Special markup on pages	Helps a search engine understand the content more precisely and can affect how the page looks in search results	Schema.org markup
Server response codes and redirects	What code the server returns for a page request, and where redirects lead	A 200 OK code means the page is available to both crawlers and visitors; any other code makes it unavailable and keeps it out of search. A 404 code means the document doesn’t exist, while 500 and 503 mean the server temporarily can’t process the request because of an error or overload. For a permanent page move, a 301 redirect is used and kept in place for at least 6 months so the search engine has time to process it; a 302 code is only suited to a temporary redirect	—
Page speed and Core Web Vitals	How fast a page loads and becomes responsive	Core Web Vitals are the LCP, INP and CLS metrics that reflect which pages Google’s core ranking systems favor. A good result is LCP under 2.5 seconds, INP under 200 milliseconds and CLS under 0.1; Google splits higher values into «needs improvement» and «poor»	—
Mobile version and HTTPS	Whether the site displays correctly on mobile devices and whether the connection is secure	Google indexes and ranks a site by the mobile version of the page (mobile-first indexing), so it needs the same content as the desktop version: removing part of the content from the mobile page can reduce search traffic. Three layout approaches are allowed — responsive design (one HTML that adapts to screen size), dynamic serving of different HTML by device type on the same URL, and separate mobile URLs; Google considers responsive design the easiest to maintain. Google treats a secure HTTPS connection as a positive quality signal; when moving from HTTP, it’s recommended to set up a permanent redirect (301 code) to the HTTPS version of the page, use secure cookies, and the HSTS mechanism, which forces the browser to always reach the site over HTTPS	—

Where to start: the priority order of work

A logical order — from basic to specific:

1. Accessibility and indexing. If a crawler can’t load a page, or it isn’t in the index, the rest of the checks are pointless for it.
2. Response codes and duplicates. Next, make sure pages respond with a 200 OK code, redirects are set up correctly — a permanent move with a 301 code, a temporary one with a 302 code — and that key pages don’t have competing copies.
3. Speed, the mobile version and HTTPS. Once the basics are in order, you can move on to finer tuning — page speed by Core Web Vitals metrics, mobile responsiveness and a secure connection.
4. Structured data and the sitemap. These are auxiliary signals: they help a crawler and a search engine work more precisely with a site that’s already accessible and fast — they don’t replace the first three points.

Starting with faster loading or markup while redirects are broken or pages are inaccessible to the crawler may show no effect in search — the pages themselves either don’t get loaded by the crawler, or their ranking signals get split between duplicates. This isn’t «do it all in a few days»: some points are checked once, others need regular monitoring after every site release.

Where it’s worth delegating

Some of the points in the table above can be checked on your own using instructions — for example, opening the robots.txt file in a browser, viewing the indexing report in Search Console, or checking a specific page’s response code in Yandex Webmaster. Regular monitoring in Yandex Webmaster is handled by the «Site diagnostics» section: it’s checked by algorithms daily and splits issues found into errors, recommendations and security violations, though the interface updates with a few days’ lag. Manually checking a response code and page availability is a quick operation, but with a large number of pages and frequent changes, it’s more efficient to track this through regular monitoring rather than a one-off check.

But technical SEO, properly done, isn’t a one-off check — it’s regular monitoring after every change to the site and prioritizing the issues found. That’s what’s known as technical SEO support — you can read more about how it works in the materials on the «Technical SEO» service.

Frequently asked questions

Is technical SEO a one-time setup or ongoing work?

Ongoing work. A site changes — new pages appear, sections get updated, sometimes there’s a move to a new address — and each such change can create a new technical issue: from an incorrect redirect to a specific page losing accessibility.

Does a small site need a technical SEO specialist?

It depends on how often the site changes and how complex its structure is. A small, static site can be checked on your own from time to time using publicly available instructions; a site with frequent changes and a large number of pages usually needs regular monitoring — for example, checking response codes, load speed and redirect behavior with every significant change.

Which tools should you start checking with on your own?

With free data sources: Google Search Console and Yandex Webmaster show how a crawler sees the site, what’s made it into the index, what response code a specific page returns, and what errors occur.

If a site is already responsive and runs on HTTPS, is there anything else to check?

Yes, periodically. Responsive layout and HTTPS remove some of the risk, but they don’t eliminate the other checks: the mobile version’s content can drift from the desktop one over time as edits accumulate, and the certificate and HTTPS settings need renewal and monitoring — for example, making sure the redirect from HTTP is correct and cookies have the Secure flag.

How quickly do search engines pick up changes in response codes and redirects?

Not instantly. Yandex recommends keeping a 301 redirect in place for at least 6 months so the search engine has time to process it, and in «Site diagnostics» the issues found show up in the interface with a few days’ lag behind the daily algorithmic check.

What happens if you put off fixing technical errors?

It depends on the scale: an isolated temporary response code or an outdated line in the sitemap usually isn’t critical, while key pages being inaccessible to the crawler, broken redirects after a move, or slow loading can reduce the site’s search visibility.

How often should you check technical SEO?

It depends on how often the site changes: new and changed pages are worth checking after every release, while the overall technical picture should be checked periodically, at a frequency that depends on the site’s size and the pace of content updates.