SEO metrics to track: what each one measures and where to read it

SEO metrics, or SEO performance metrics, are the numbers that named tools report about a site's search performance, and each tool's number counts something different. A metric is only as clear as the definition the tool gives it, which is why the same word can name two different counts in two different tools.

This page lists fourteen important SEO metrics, grouped by the tool that reports them: Google Search Console, Google Analytics 4, Core Web Vitals, the link tools and the crawlers. Each entry gives the tool's own definition, the scale or threshold its documentation states and where to read the number. One practitioner has published a year of his own site's figures, quoted below with his dates, and the last sections give the five tools, what each one reports and a short FAQ.

What an SEO metric is

An SEO metric is a number a named tool reports, and the tool matters as much as the number, because two tools can give the same words to different counts. Google Search Console's average position is an average across the queries and countries a page appeared for, not a rank read for one query in one place. Google Analytics 4's bounce rate is not the Universal Analytics bounce rate, so a figure from before the move to Google Analytics 4 is a different number from a figure after it. Every definition below was read on 4 October 2026 from the tool's own documentation.

The Google Search Console metrics

Google Search Console reports what happened when a site appeared in search results, and the Performance report is where its counts live. The documentation, read on 4 October 2026, describes the default view: "The default view of the report shows click and impression data for your site in Google Search results for the past three months."

1. Clicks and impressions

The Performance report defines the first count: "Clicks: The number of times a user clicked your site from Google Search results." And the second: "Impressions: How many times your site appeared in Search results."

Read the two together, by page and by query. A page can appear many times and be clicked rarely, or appear rarely and be clicked every time, and neither count on its own says which.

Christian Ott is an SEO consultant who publishes his own site's numbers at seo-kreativ.de. He wrote on 9 July 2026 that the site's impressions went from 6,590 in July 2025 to 561,659 in June 2026 and its clicks from 33 to 1,078 a month, from Search Console data covering 1 July 2025 to 8 July 2026. Both counts rose, but impressions rose far faster than clicks.

For the wider traffic picture beyond the results pages, a separate guide shows how to check your website traffic.

2. Click-through rate

The Performance report defines the rate: "CTR (click-through rate): The click count divided by the impression count."

A rate moves when either count moves. If impressions rise faster than clicks, the rate falls while the click count is still rising. Ott watched that pattern on his own site: "I can see it in my own CTR curve, which fell from 0.92 % in September 2025 to 0.19 % in June 2026 while my position improved at the same time."

AccuRanker, a rank-tracking tool, wrote on 2 June 2026 that, in its own study, the CTR for a rank 1 result can vary from 0% to 75% with the layout of the results page. A CTR is read against the layout and the position, not alone.

3. Average position

For keyword rankings, the Performance report defines the last of the four: "Average position: The average position of the topmost result from your site."

The average is taken over every query and every country the page appeared for in the chosen date range. A page at position 3 for one query and 40 for another shows a number between them, so the figure is not a rank read. A rank tracker reads one position for one query in one place, which is a different number from the average. The average also moves when a page gains or loses queries, not only when a single position moves. Ott's table on the same page gives an average position of 60.5 in July 2025 and 9.5 in June 2026 for his site.

For a single position rather than an average, a separate guide shows how to check a ranking one query at a time.

The Google Analytics 4 metrics

Where Google Search Console counts what happened in the results, Google Analytics 4 counts what visitors did on the site itself. The definitions below were read on 4 October 2026 in the Google Analytics 4 documentation.

4. Organic sessions

The Google Analytics 4 metrics reference defines the session count as the number of sessions that began on your website or application, and by default a session ends after 30 minutes of user inactivity. Ahrefs' guide to SEO performance defines organic traffic as all non-paid clicks that come from search engines, and Google Analytics 4 groups the sessions those clicks begin under its Organic Search channel, which its documentation defines as the channel by which users arrive at a site or app through non-ad links in organic-search results.

Google Search Console counts clicks and Google Analytics 4 counts sessions, so the two counts differ. One click can lead to two sessions if the visitor stops for more than 30 minutes and then carries on.

5. Engagement rate and bounce rate

The Google Analytics 4 help page defines the bounce rate: "The bounce rate is the percentage of sessions that were not engaged."

An engaged session is one that lasts longer than 10 seconds, has a key event or has two or more page or screen views, and the engagement rate is the percentage of sessions that were engaged. The two rates add up to 100%, so either one can be read from the other. The metrics reference also lists average session duration, the average length of a session in seconds, and views per session, the number of pages or screens viewed per session.

Universal Analytics counted the bounce rate differently, as the share of sessions in which the visitor viewed only one page and triggered only one request to the Analytics server. A visitor who reads one page for longer than 10 seconds and leaves is an engaged session in Google Analytics 4 and was a bounce in Universal Analytics. A bounce rate from before the move to Google Analytics 4 is a different number from the one after it.

6. Key events

Google Analytics 4 defines the count: "A key event is an event that measures an action that's particularly important to the success of your business."

A key event is the Google Analytics 4 counterpart of what Universal Analytics called a goal, and Universal Analytics counted a completed goal as a conversion, once per session. A form sent, a sign-up or a purchase can each be marked as a key event by the site owner, and Google Analytics 4 then counts each one.

7. Purchase revenue

Google Analytics 4 reports purchase revenue as the sum of revenue from purchases made on the site or app, minus any refunds given, and only where purchases are set up.

A return on SEO spend is this figure set against the cost. The revenue comes from Google Analytics 4; the cost comes from what was spent on the work.

Core Web Vitals

Core Web Vitals are three defined measures of how a page loads, how it responds and how steady it holds its layout.

8. Largest Contentful Paint, Interaction to Next Paint and Cumulative Layout Shift

Google's web.dev, on a page last updated 31 October 2024 and read on 4 October 2026, defines the first of the three: "Largest Contentful Paint (LCP): measures loading performance. To provide a good user experience, LCP should occur within 2.5 seconds of when the page first starts loading."

The same page gives Interaction to Next Paint, which measures interactivity, a threshold of 200 milliseconds or less, and Cumulative Layout Shift, which measures visual stability, a threshold of 0.1 or less. It states that the threshold to measure is the 75th percentile of page loads, split across mobile and desktop devices, so a page is assessed at that percentile for all three, not at the average visit.

Page load time is not one of the three; the three are what the documentation defines.

The link metrics

Four entries cover the backlink tools, and two of them are scores that belong to the tool that computes them. Each definition below was read on 4 October 2026 in the tool's own documentation.

9. Backlinks and referring domains

Ahrefs' academy defines the pair: "The backlinks metric is a total count of all backlinks pointing at a target, while referring domains is the count of unique websites that point at a target."

The two counts move differently: one site linking to a page again and again adds to the backlink count and still counts as one referring domain. Ott gives his own counts with the tool named: "Ahrefs (free) counts 343 backlinks - but only 163 of them are dofollow, 182 are nofollow and 3 are UGC (measured in Ahrefs)."

The whole set of links a site holds is its backlink profile, and the two counts are read in that context. When the question is how many links a page needs, the guide to how many backlinks counts referring domains, not backlinks.

10. New and lost referring domains

Similarweb's help page defines the first count: "New Referring Domains represents the number of domains that have recently started linking to your website." And the second: "Lost Referring Domains indicates the number of domains that used to link to your site but have now stopped doing so."

The industry's word for the rate of change is link velocity. Ahrefs' glossary defines it as the rate at which a site or page gains backlinks, measured in links or referring domains per month. Similarweb's page reports the two counts, new and lost, for the past 12 months, and the pair is read together because gains and losses can run at the same time.

Checking the links a page already holds is a link audit, and the new and lost counts are where that work shows up over time.

11. Moz Domain Authority

Moz's Domain Authority is described on Moz's own page, last updated 18 March 2025, as a score that predicts how likely a site is to rank compared with competitors. The page gives the scale: "The score ranges from 1 to 100, with higher scores indicating a greater ability to rank."

The score is Moz's, computed from Moz's own data, and it is read in Moz's tools. The Moz Domain Authority guide on this site covers what the score is and how it is calculated.

12. Ahrefs Domain Rating

Ahrefs' Domain Rating is defined in Ahrefs' help centre, on a page dated 3 September 2026: "Domain Rating (DR) shows the strength of a website's backlink profile compared to the others in our database on a 100-point scale." The same page is direct about single figures: "It’s not possible to say that a Domain Rating of 30 is good, or 50, or 60, or 70."

DR is a different score from a different database, so a site's DA and DR differ, and neither figure is the other's mistake.

Our Guest Posts are tiered by the minimum Moz Domain Authority of the placement site. Each site is measured with Moz Domain Authority and cross-checked against Ahrefs Domain Rating and live traffic: DA sets the tier and price, and DR and live traffic tell us whether the number is earned. When we vet a site, we weigh indexed pages, organic traffic and its trend, Moz DA, Ahrefs DR, referring domains and link-profile strength together, not one score alone.

Our free DA and DR checker reports both scores for one domain. In a July 2026 sample of its database, DR was above DA on 42.1% of domains. The sample holds 29,632 checks since the tool launched in February 2026, across 15,357 unique domains, with the latest check kept per domain. The sample describes the domains people chose to check, not the web.

The reasons the two scores differ are set out in why Moz DA and Ahrefs DR disagree. For the wider set of link measures behind the scores, see how link authority is measured.

The crawl metrics

Two numbers come from crawling the site itself, and the documentation behind them was read on 4 October 2026.

13. Site health score

Two tools publish a score under almost the same name, and the two are not the same number. Semrush's knowledge base gives its Site Health Score as a percentage between 0% and 100% that weighs the errors and warnings found during the crawl against the number of checks performed. Ahrefs' help centre, on a page dated 3 September 2026, gives its Health Score as the proportion of internal URLs crawled by Site Audit that have no errors.

Each score is read inside the tool that computed it, from that tool's own crawl. Say whose score is being quoted, because the two are not comparable: one weighs errors and warnings against the checks performed, and the other counts the share of crawled URLs without errors.

14. Indexed pages and response codes

Google Search Console's Page indexing report, as its documentation describes it, shows how many URLs on a site have been crawled and indexed.

A crawler lists the response code each URL returned, and the 4XX and 5XX codes are the rows to work through, because those are the URLs that returned a client or server error. The codes behind those rows are listed in the guide to HTTP status codes. The crawl side of the same topic is covered under crawl budget.

Where to read each metric: the five tools

Each tool below reports the metrics listed after its name.

• Google Search Console: clicks, impressions, CTR and average position in the Performance report; indexed pages in the Page indexing report. The Performance report's default view covers the past three months.
• Google Analytics 4: sessions, engagement rate and bounce rate, key events and purchase revenue. Its counts begin where the click ends, with what visitors did on the site.
• Semrush: Site Health Score from Site Audit, position tracking and backlink reports. Its Site Health Score weighs errors and warnings against the checks performed in the crawl.
• Ahrefs: Domain Rating, backlinks and referring domains, Health Score from Site Audit, Rank Tracker. Its Health Score counts the share of crawled internal URLs without errors.
• Moz: Domain Authority and Page Authority, plus link counts. Both scores are read in Moz's tools.

Frequently asked questions

What are SEO metrics?

SEO metrics are numbers that named tools report about a site's search performance, and each tool's number counts something different. The fourteen on this page come from Google Search Console, Google Analytics 4, Google's web.dev, Ahrefs, Moz, Semrush and Similarweb, and each entry gives the tool's own definition and scale. The same word can name a different count in a different tool, so the tool's definition comes first.

Which SEO metrics should I track first?

The key SEO metrics to track first are the four Google Search Console numbers: clicks, impressions, CTR and average position, because they count what happened in the results for your own pages. Add the Google Analytics 4 numbers, sessions, engagement rate, key events and purchase revenue, for what visitors did on the site. Add the link counts, backlinks, referring domains and new and lost referring domains, when you are building or buying links.

How do I track keyword rankings?

Google Search Console gives an average position, which is an average across the queries and countries a page appeared for. A rank tracker reads one position for one query in one place. The two are different numbers, and the average sits between the positions a page holds across its queries.

What is a good Domain Authority score?

Moz's scale for Domain Authority runs from 1 to 100, and Ahrefs says of its own Domain Rating that no single figure can be called good. In our checker's July 2026 sample of 15,357 unique domains, the mean DA was 27.9 and the mean DR 28.6. That sample describes the domains people chose to check, not the web. Moz's own page says the same score might be exceptional in one industry and low in another, so a score is read against sites in the same niche.