Unique visitor

Why tools disagree about visitors

Every analytics tool needs some way to decide that two pageviews came from the same person. Google Analytics stores an ID in a cookie that can last two years. A login gives you a user ID. A cookieless tool works from what arrives with the request, which is mostly the IP address and the browser.

The window matters as much as the method. A cookie can recognise a reader across months, so its monthly unique count is smaller than the sum of its daily counts. A tool that forgets visitors every day can only add the days up. Each number is right for the question it answers, and comparing one with the other is a common reason two tools seem to disagree.

How Vireo counts a visitor

Vireo combines the visitor's IP address and browser with a secret that changes every day, and stores only the scrambled result. It keeps today's and yesterday's secrets and deletes anything older, so once a day's secret is gone, nobody can work out which address a result came from.

Within a single day, Visitors is a true unique count: ten pageviews from one reader are one visitor. Over a longer range, the Visitors card adds up each day and says "daily uniques, summed". A reader who comes back on three days in a month counts three times.

Vireo doesn't estimate unique people per month. The privacy model makes that number unknowable, and printing a guess would invite comparisons with tools that measure something else.

Things that change the count

Two people behind the same office or home router, using the same browser version, can look like one visitor for that day. One person who switches from Wi-Fi to mobile data gets a new address and counts twice. Over a day these mostly even out, and they're the price of storing nothing on the device.

Logged-in administrators aren't counted unless you turn on "Track logged-in admins". Browsers sending Do Not Track or Global Privacy Control aren't counted at all. Bots are kept out and reported separately, which is the usual reason Vireo shows fewer visitors than a server-log tool.

Comparing with Google Analytics

If you're moving from Google Analytics, compare daily visitors to GA4's daily active users rather than monthly totals. Over a month, expect Vireo's summed figure to be higher than GA4's users, because GA4 recognises returning readers across days and Vireo doesn't.