Once your PostHog instance is up and running, the next step is to start sending events.
You can send custom events using capture
:
posthog.capture('user_signed_up');
Tip: We recommend using a
[object] [verb]
format for your event names, where[object]
is the entity that the behavior relates to, and[verb]
is the behavior itself. For example,project created
,user signed up
, orinvite sent
.
Setting event properties
Optionally, you can also include additional information in the event by setting the properties value:
posthog.capture('user_signed_up', {login_type: "email",is_free_trial: true})
Page views and autocapture
By default, PostHog automatically captures the following frontend events:
- Pageviews, including the URL.
- Autocaptured events, such as any
click
,change of input
, or submission associated witha
,button
,form
,input
,select
,textarea
, andlabel
tags.
If you prefer to disable these, set the appropriate values in your configuration options.
Single-page apps and pageviews
PostHog automatically sends pageview
events whenever it gets loaded. If you have a single-page app, that means it only sends a pageview once (when your app loads).
To make sure any navigating a user does within your app gets captured, you can make a pageview call manually.
posthog.capture('$pageview')
This automatically sends the current URL along with other relevant properties.
Event ingestion
It's a priority for us that events are fully processed and saved as soon as possible. Typically, events will be usable in queries within a few minutes.
Advanced: Anonymous vs identified events
PostHog captures two types of events: anonymous and identified
Identified events enable you to attribute events to specific users, and attach person properties. They're best suited for logged-in users.
Scenarios where you want to capture identified events are:
- Tracking logged-in users in B2B and B2C SaaS apps
- Doing user segmented product analysis
- Growth and marketing teams wanting to analyze the complete conversion lifecycle
Anonymous events are events without individually identifiable data. They're best suited for web analytics or apps where users aren't logged in.
Scenarios where you want to capture anonymous events are:
- Tracking a marketing website
- Content-focused sites
- B2C apps where users don't sign up or log in
Under the hood, the key difference between identified and anonymous events is that for identified events we create a person profile for the user, whereas for anonymous events we do not.
💡 Tip: Under our current pricing, anonymous events can be up to 4x cheaper than identified ones (due to the cost of processing them), so it's recommended you only capture identified events when needed.
How to capture anonymous events
The JavaScript Web SDK captures anonymous events by default. However, this may change depending on your person_profiles
config when initializing PostHog:
person_profiles: 'identified_only'
(recommended) (default) - Anonymous events are captured by default. PostHog only captures identified events for users where person profiles have already been created.person_profiles: 'always'
- Capture identified events for all events.
For example:
posthog.init('<ph_project_api_key>',{api_host: 'https://us.i.posthog.com',person_profiles: 'always'})
How to capture identified events
If you've set the personProfiles
config to IDENTIFIED_ONLY
(the default option), anonymous events are captured by default. Then, to capture identified events, call any of the following functions:
identify()
alias()
group()
setPersonProperties()
setPersonPropertiesForFlags()
setGroupPropertiesForFlags()
When you call any of these functions, it creates a person profile for the user. Once this profile is created, all subsequent events for this user will be captured as identified events.
Alternatively, you can set personProfiles
to ALWAYS
to capture identified events by default.