Weekly Active Users

Weekly Active Users is a number companies use to measure the success of their apps and websites. Translated, the term means: weekly active users. What is counted is how many different people have used a service at least once within seven days. Someone who drops by twenty times in the same week still only counts once. What matters, then, is not how often someone comes, but how many come at all. The abbreviation WAU appears constantly in quarterly reports, stock market announcements, and press releases from tech companies.

What the number reveals about a product

An app can have millions of downloads and still be dead. Many people install something out of curiosity and never open it again. The number of sign-ups therefore says little. WAU, by contrast, measures real behavior: only those who actually use the product are counted.

For investors, this is one of the most important figures of all. If the number grows, revenue usually grows too later on, since active people see advertising or take out subscriptions. If it shrinks, that is a warning sign, often long before earnings decline. When OpenAI reported in 2025 that ChatGPT had around 800 million weekly users, this was precisely the figure meant.

However, WAU should not be overestimated. A company decides for itself what counts as active. Is simply opening the app enough, or does someone have to write, buy, or upload something? Because there is no uniform rule for this, figures from different companies are only comparable to a limited extent.

How clicks become a metric

Technically, the service logs every action along with an identifier for the account or device. At the end of the week, duplicate identifiers are removed. What remains is the number of distinct people. Experts call this deduplication, which simply means: everyone counts only once.

A rolling window is usually used. The program looks back at the last seven days every single day. This produces a smooth curve instead of a jump every Monday. That smooths out fluctuations, since people behave differently on weekends than on weekdays.

Related metrics are DAU and MAU, meaning daily and monthly active users respectively. Dividing DAU by MAU yields what is called stickiness, a measure of loyalty. If the value is 0.5, an average user comes on 15 out of 30 days. WAU deliberately sits in between: the daily figure reacts too nervously to holidays, while the monthly figure conceals problems for too long.

WAU in quarterly figures and headlines

You most often encounter this number in business news. When Meta, Spotify, Discord, or OpenAI publish quarterly figures, user numbers are often listed higher up than profit. Stock prices sometimes react more sharply to weak user growth than to weak revenue.

The metric is also standard in games. Developers use it to see whether a new update brings people back or drives them away. Within companies themselves, WAU curves hang on screens in the office, and teams get goals such as: ten percent more active users by summer.

A typical mistake is confusing WAU with visits or page views. A report of one billion views sounds enormous but may come from just a few million people. Anyone who wants to read headlines correctly should therefore pay close attention to whether the report is talking about actions or about people.