Key metrics, explained simply
Plain-English definitions of the most important website analytics metrics — sessions, bounce rate, conversion rate, and more — with guidance on what they actually mean for your business.
- Difficulty
- Beginner
When you open Google Analytics, you are immediately confronted by numbers and terms that can feel like a foreign language. This guide decodes the most important ones and explains what they actually mean for your business.
Quick summary
The metrics that matter most for most businesses are: users (how many people visited), sessions (how many visits), engagement rate (are people engaging?), and key events — GA4's name for the actions you want people to take. Everything else provides context.
Users
A user is a person (or more precisely, a browser/device) that visited your website. If the same person visits on Monday and again on Friday, they count as one user but two sessions.
One thing to know: the column labelled "Users" in most GA4 reports is Active users, not everyone who loaded a page. An active user is someone who had an engaged session, or whose visit registered as a first visit or as engagement time. Total Users is a separate metric you have to go and ask for, usually in an exploration.
What it tells you: Your overall audience size. Is your reach growing?
Sessions
A session is a single visit to your website. One user can have multiple sessions. A session starts when someone arrives and ends after a period of inactivity — 30 minutes by default, though that timeout can be changed in your web data stream's tag settings.
What it tells you: How often people are visiting — not just how many people.
Pageviews (now called "Views" in GA4)
A view is recorded every time any page on your site is loaded. If one visitor reads five pages in a single visit, that is five views — repeat views of the same page count too. Universal Analytics also had a "Unique Pageviews" metric, which stripped out those repeats; GA4 has no equivalent.
What it tells you: Which content is being read and how actively people are browsing.
Engagement rate
Engagement rate measures the percentage of sessions that counted as engaged. A session is engaged if it does any one of three things: lasts longer than about 10 seconds, triggers a key event, or racks up two or more page or screen views.
What it tells you: Are people actually interested in your content, or are they landing and leaving immediately?
GA4 has both engagement rate and bounce rate
In the old version of Google Analytics (Universal Analytics), the headline metric was "bounce rate," and it meant a visit to a single page. GA4 keeps both metrics but redefines them against each other: bounce rate is simply the inverse of engagement rate — the share of sessions that were not engaged. Neither one appears in most reports by default; an Editor or Administrator has to add the metric to a detail report first.
Bounce rate
Bounce rate is the opposite of engagement rate — it is the percentage of sessions where the visitor left without engaging. A high bounce rate is not always a problem. If someone finds your phone number and calls you, they may "bounce" but they converted perfectly.
What it tells you: Context-dependent. High bounce on a key service page may need attention. High bounce on a contact page is fine.
Average engagement time
This is how long your site was actually in focus in someone's browser, added up and divided by the number of active users. There is a second, separate metric — average engagement time per session — which divides by sessions instead, so check which one your report is showing before you compare two numbers.
What it tells you: Are people reading or just scanning? Google publishes no target figure, so compare a page against your own other pages and against its own past months rather than against a number you read somewhere.
Conversion rate
A conversion, in everyday language, is a specific action you want visitors to take — filling in a form, making a purchase, clicking a phone number link. Google Analytics now calls these key events: you mark an event as a key event and it starts appearing as a column and a metric in your reports. In current Google terminology "conversion" means something narrower — an action used to measure and optimise Google Ads campaigns.
The conversion rate is the share of visits that result in one of those actions. GA4 splits it into two on-screen metrics: session key event rate (sessions with a key event ÷ total sessions) and user key event rate (users who performed a key event ÷ total users). Check which one you are looking at before comparing two figures.
What it tells you: Is your website actually working? This is the single most important business metric.
Traffic source / channel
This tells you how visitors found your site. These are GA4's own channel names, and they are worth using exactly — "Social" on its own is not one of them:
| Channel | What it means |
|---|---|
| Organic Search | Arrived via a non-ad link in search results, including Google's AI Overviews and AI Mode |
| Direct | Typed your URL directly or used a saved link or bookmark |
| Referral | Clicked a non-ad link on another site, such as a blog or news site |
| Organic Social | Clicked a non-ad link on a social site |
| Paid Social | Clicked an ad on a social site |
| Clicked a link in an email | |
| Paid Search | Clicked an ad on a search engine — Google, Bing, Baidu and so on |
| AI Assistant | Arrived from a tool like ChatGPT, Gemini, Copilot or Grok |
There are more channels than this in the full list, and the default ones cannot be edited — though you can build your own custom channel groups alongside them.
New vs returning users
- New users — visiting your site for the first time (on that device/browser)
- Returning users — have visited before
What it tells you: How many people are discovering you vs. how many loyal visitors you have.
Easy to miss
These numbers are estimates, not exact counts. Privacy settings, ad blockers, and browser restrictions mean some visits are not captured at all. Treat all analytics data as directional — use it for trends and comparisons, not as a census.
Common questions
Which metric should I focus on most?
Start with conversions and traffic trends. Is traffic growing? Are conversions happening? Everything else helps explain why those numbers look the way they do.
What is a good engagement rate?
Google does not publish a benchmark, and any figure quoted online is somebody's private sample rather than an official target — so we will not give you one either. Compare your own months against each other instead: a rate that is climbing tells you more than any single number. If it looks low, the useful next question is whether it is low everywhere or only on certain channels, sources or pages.
Why do my numbers sometimes go down even when nothing changed?
Seasonal patterns, algorithm changes, and external news events can all affect traffic. Always compare year-over-year, not just month-over-month, to spot true trends.
What is the difference between a session and a visit?
In GA4, sessions and visits mean the same thing. "Visit" is the everyday word; "session" is what GA4 calls it.
Related guides
- Users vs sessions vs views
- Engagement, bounce & time on page
- Conversions & goals explained
- Vanity metrics vs meaningful metrics
- Understanding your monthly report
- Troubleshooting analytics problems
Need a hand?
Learn more
Last updated
A tour of the GA4 dashboard
A plain-English walkthrough of the Google Analytics 4 interface — what each section shows and where to find the numbers that matter most.
Users vs sessions vs views
A clear, jargon-free explanation of three easily confused analytics numbers — users, sessions, and views — and what each one tells you about your website.