When I’m building a Trends insight in PostHog, I often run into the same problem: one product outcome shows up under multiple event names. Instead of creating an Action (or doing mental math across multiple lines), I now combine those events directly inside the Trends chart and track them as one series.
How I use it in PostHog
- I go to Product analytics → Trends.
- In the series picker (where you normally choose a single event), I select the first event I care about.
- Then I add the other related events into the same series using inline combination.
- PostHog treats those selected events as one line on the chart.
What it actually does (important detail)
This combination is a logical OR. In plain English: if any of the selected events happen, PostHog counts it toward that combined series.
Why this matters in practice
For me, this removes the “naming drift” overhead. I can keep my Trend focused on the outcome I’m measuring, even if the product has multiple valid events that represent the same intent (because different teams shipped different tracking names, or the event schema evolved over time). And I get the result immediately, without creating custom Actions just to make a single chart readable. For a broader check of event meaning and data quality, see our PostHog audit.
If you want the official reference for the feature, it’s documented under Trends as “Combine events inline.”
Frequently asked questions
Why combine events inline instead of creating a custom Action?
The article’s use case is one product outcome appearing under multiple event names; it combines those events in the Trends chart as one series instead of creating an Action or doing mental math across multiple lines.
When should different event names be treated as the same outcome?
The article’s fit is multiple valid events that represent the same intent, including names shipped by different teams or an event schema that evolved over time.
Does inline combination use OR or AND logic?
This combination is a logical OR. In plain English: if any of the selected events happen, PostHog counts it toward that combined series.
What does “high value” mean when choosing events for the metric?
A high-value event is one where users experience the real value of the product or demonstrate meaningful usage.
How should I handle event schema changes over time?
Version events as the app evolves so older and newer events can be distinguished while historical data is preserved.
What naming convention example is given for custom events?
The source’s example is to use lowercase, present tense, and snake case for custom events.
What is a small first step if analytics setup feels complicated?
Start small: choose a specific product or feature, track its usage with autocapture and/or custom events, and visualize the data with Trends and retention graphs.
When should I check the combined metric after shipping?
Check it right after shipping: watch sessions, monitor error rates, and look for changes in key metrics such as adoption and activation trends.
