GA4 Tracking Spec / JWIEDEMAN

Basics

GA4 records everything as an event with up to 25 parameters. Sessions, users, and conversions are built from events during processing. Choose events in this order:

Automatic Collected by gtag.js or the Firebase SDK with no code.
Enhanced measurement Web only. Collected automatically when the enhanced measurement toggle is on in the data stream.
Recommended Defined by Google with fixed names and parameters. Use the exact names so reports and integrations work.
Custom Named by you. Follows GA4 naming rules; parameters must be registered as custom dimensions to appear in reports.

A Key event marker means the event is a business outcome you should mark as a key event (formerly "conversion") in Admin. Use the same event names and parameters on web, app, and TV, so one report covers every platform.

Rules

Names: snake_case, start with a letter, letters, numbers, and underscores only, 40 characters or fewer. Names are case-sensitive: Sign_Up and sign_up are two events.
Reserved: Do not start event or parameter names with _, firebase_, ga_, google_, or gtag., and do not send automatically collected names such as first_open or session_start.
Parameters: 25 per event. Names up to 40 characters; values up to 100 characters (page_title 300, page_referrer 420, page_location 1,000).
Custom definitions: Parameters only appear in reports after you register them as custom dimensions or metrics, and only from that day forward. Standard properties allow 50 event-scoped dimensions, 25 user-scoped dimensions, and 50 metrics. BigQuery export receives every parameter regardless.
User properties: 25 per property; names up to 24 characters, values up to 36. Use them for stable traits (plan, language), not for events.
Apps: 500 distinct event names per app. Plan names up front; dynamic names such as click_button_37 exhaust the limit.
Ecommerce: Send currency with every value, an items array on product events (each item with item_id or item_name, up to 200), and a unique transaction_id on purchase.
Personal data: Never send names, emails, phone numbers, or addresses, including inside URLs. user_id must be an internal ID.
Consent: Set Consent Mode defaults before any tag runs and update them when the user chooses. With analytics_storage denied, gtag.js sends cookieless pings.

Setup

Install once per platform. Everything else in this spec builds on these calls.

Web: consent defaults, tag, and identity

<script>
  window.dataLayer = window.dataLayer || [];
  function gtag(){dataLayer.push(arguments);}
  gtag('consent', 'default', {
    ad_storage: 'denied', ad_user_data: 'denied',
    ad_personalization: 'denied', analytics_storage: 'denied',
    wait_for_update: 500
  });
  gtag('js', new Date());
  gtag('config', 'G-DEMO12345', {
    user_id: 'u_48213'   // only when signed in
  });
  gtag('set', 'user_properties', { plan: 'plus' });
</script>
<script async src="https://www.googletagmanager.com/gtag/js?id=G-DEMO12345"></script>

Android (Kotlin, Firebase)

private lateinit var firebaseAnalytics: FirebaseAnalytics
firebaseAnalytics = Firebase.analytics

// After sign-in
firebaseAnalytics.setUserId("u_48213")
firebaseAnalytics.setUserProperty("plan", "plus")

// Consent Mode
firebaseAnalytics.setConsent(mapOf(
  ConsentType.ANALYTICS_STORAGE to ConsentStatus.GRANTED,
  ConsentType.AD_STORAGE to ConsentStatus.DENIED,
  ConsentType.AD_USER_DATA to ConsentStatus.DENIED,
  ConsentType.AD_PERSONALIZATION to ConsentStatus.DENIED
))

iOS (Swift, Firebase)

import FirebaseAnalytics

// After sign-in
Analytics.setUserID("u_48213")
Analytics.setUserProperty("plus", forName: "plan")

// Consent Mode
Analytics.setConsent([
  .analyticsStorage: .granted,
  .adStorage: .denied,
  .adUserData: .denied,
  .adPersonalization: .denied
])

TV apps and servers (Measurement Protocol)

POST https://www.google-analytics.com/mp/collect
     ?measurement_id=G-DEMO12345&api_secret=<API_SECRET>

{
  "client_id": "1873301823.1728201600",  // generate once, store on device
  "user_id": "u_48213",
  "user_properties": { "plan": { "value": "plus" } },
  "events": [{
    "name": "screen_view",
    "params": {
      "screen_name": "Home",
      "session_id": "1728201600",       // needed for sessions
      "engagement_time_msec": 100       // needed for active users
    }
  }]
}

The api_secret is created under Admin → Data streams → Measurement Protocol API secrets. Keep it on servers where you can; a secret shipped inside a TV app can be extracted. Validate payloads against /debug/mp/collect, which returns errors instead of the silent 204 of the real endpoint.

Pages and screens

Page load

Web
App
TV / OTT

Every web page load. Sent by the config command, so most sites need no extra code.

Try it

page_location carries utm_* and gclid parameters. GA4 reads traffic source from it, so do not strip them before the hit is sent.
Do not also send page_view from a GTM tag. Two systems sending the same event doubles the count.

Single-page app route change

Web
App
TV / OTT

The URL changes without a full page load (React, Vue, Angular, Next.js client navigation).

Try it

Send page_view after the new title and URL are set; otherwise the event reports the previous page.
If the router changes the URL more than once per navigation, turn off "page changes based on browser history events" and send page_view yourself.

App or TV screen

Web
App
TV / OTT

A screen becomes visible in a native app or TV app. The equivalent of page_view.

Try it

Log it manually for Jetpack Compose, SwiftUI, React Native, and Flutter, which the SDK cannot see.
TV apps without a Firebase SDK (Roku, Tizen, webOS) send screen_view over the Measurement Protocol.

Scroll depth

Web
App
TV / OTT

How far down the page people read.

Try it

25%50%75%90%

Scroll this box. Thresholds fire once each as they pass the bottom of the box.

If you add thresholds, turn enhanced scroll off and send all of them (including 90) from one place, so 90% is not counted twice.
Apps and TV apps have no page scroll; track meaningful list positions with view_item_list or custom events instead.

Navigation and discovery

Menu, footer, and breadcrumb links

Web
App
TV / OTT

Internal navigation. One event for every menu, with the menu named in a parameter.

Try it

nav_location values: header, footer, breadcrumb, sidebar, tab_bar (app), side_menu (TV).
The destination page_view already records the visit; nav_click tells you which menu led there.

Outbound link

Web
App
TV / OTT

A link to another domain.

Try it

Google Analytics developer docs ↗

Add your other domains under "Configure your domains" so links between them count as internal, not outbound.

Tabs

Web
App
TV / OTT

Switching between panels of content on the same page or screen.

Try it

Overview panel (shown by default, not tracked).

Accordion and FAQ

Web
App
TV / OTT

Expandable sections.

Try it

What is the return policy?

Returns are accepted within 30 days.

How long does shipping take?

Two to five business days.

Is there a warranty?

One year on all footwear.

Carousel

Web
App
TV / OTT

A rotating set of slides.

Try it

Slide 1 of 3: New arrivals

Autoplay advances every 6 s and is not tracked.

If a slide is a promotion, also send view_promotion and select_promotion for it.

Site and in-app search

Web
App
TV / OTT

A search box.

Try it

On the web, use either the enhanced event or a manual search event, not both.
Send the term as typed, lowercased and trimmed. If people search for order numbers or email addresses, redact them first.

Filters and sorting

Web
App
TV / OTT

Refining a list of products, articles, or titles.

Try it

Size In stock Sort

Pagination and "load more"

Web
App
TV / OTT

Requesting the next set of results.

Try it

Forms, accounts, and onboarding

Form

Web
App
TV / OTT

A contact, quote, or application form, from first interaction to confirmed submission.

Try it

Enhanced form events fire on the browser submit, including submissions that later fail. Use generate_lead (or sign_up) on confirmed success as the key event.
Never send field values. Names, emails, and phone numbers in GA4 break Google's terms.

Sign in and sign out

Web
App
TV / OTT

Authentication, and attaching the account ID to later events.

Try it

Signed out. user_id is not set.

user_id must be your own internal account ID. Never an email address or anything a person could be identified by.
Set user_id before sending login so the login event itself carries it.

Onboarding and tutorials

Web
App
TV / OTT

A guided first-run flow or product tour.

Try it

For step-level analysis, add a custom tutorial_step event with step_number and step_name.

File upload

Web
App
TV / OTT

Attaching a file to a form or profile.

Try it Attach a file Only the extension and size are sent; the file stays in your browser.

Banners, dialogs, and consent

Promotion banner

Web
App
TV / OTT

An internal promotion: hero banner, sale strip, or featured tile.

Try it

Spring sale: 25% off running gear Use code SPRING25 · Shop now →

Promotion parameters can also be set per item inside items, when one banner features specific products.

Call-to-action button

Web
App
TV / OTT

A prominent button such as "Start free trial" or "Book a demo".

Try it

cta_click measures the button. The outcome (sign_up, begin_checkout, generate_lead) is a separate event, and the outcome is the key event.
Keep cta_text in one language. Translated labels split one button into several rows.

Modal dialog

Web
App
TV / OTT

An overlay that asks for attention: an offer, a survey, a confirmation.

Try it

Content engagement

Content card

Web
App
TV / OTT

Selecting an article, video, or document from a list.

Try it

For products, use select_item with items instead.

File download

Web
App
TV / OTT

A link to a PDF, spreadsheet, archive, or installer.

Try it

Download the spec (PDF)

Rate, like, save, and follow

Web
App
TV / OTT

Lightweight reactions to content.

Try it

Video and audio

Video player

Web
App
TV / OTT

Playback on any player: HTML5, YouTube, app, or TV. Same names everywhere so one report covers all.

Try it

Product tour · 2:00

0:00

Plays at 10× speed for the demo.

Enhanced measurement only covers embedded YouTube players with the JS API enabled. For every other player, send these events yourself with the same names and parameters.
Do not send a heartbeat every few seconds. Percent milestones answer "how much was watched" at a fraction of the volume.
The Mock Player in Analytics > Tools covers the full media spec: ads, quality, buffering, live streams, and six vendors.

Audio and podcasts

Web
App
TV / OTT

Audio playback. Mirrors the video events with an audio_ prefix.

Try it

Ecommerce

Product list to purchase

Web
App
TV / OTT

The full ecommerce funnel. Every event carries an items array with the same item fields.

Try it

The list sends view_item_list when it scrolls into view.

Cart $0

Select a product to begin.

value is revenue excluding tax and shipping, and it needs currency. Without currency, GA4 drops the revenue.
transaction_id deduplicates purchases. Reloading the confirmation page must not send a second purchase.
Each item needs item_id or item_name. Keep item fields identical across all events so funnels join.
Clear the previous ecommerce object in the dataLayer ({ ecommerce: null }) before each GTM ecommerce push.

TV, subscriptions, and casting

TV home rows and remote control

Web
App
TV / OTT

Browsing rows of titles with a D-pad. Focus moves on every key press; only selections are tracked.

Try it

Continue watching

Trending

Click here, then use arrow keys and Enter. Focus moves not sent: 0

Never send focus changes. A ten-minute browse can produce hundreds, and they say nothing about intent.
Most TV platforms have no GA4 SDK. Send these events from the app over the Measurement Protocol with a client_id you generate once and store on the device.

Paywall, trial, and subscription

Web
App
TV / OTT

Gated content and the subscription lifecycle.

Try it

Renewals happen with nobody on the page. Send them from your billing system over the Measurement Protocol with the subscriber's client_id and user_id.
App store purchases are logged automatically as in_app_purchase once the store account is linked.

Casting and AirPlay

Web
App
TV / OTT

Sending playback from a phone or browser to a TV.

Try it

While casting, playback events still come from the sender (phone or browser); add a casting: true parameter to them.

App lifecycle

Automatically collected app events

Web
App
TV / OTT

Logged by the Firebase SDK with no code. Shown here so you know not to send them yourself.

Try it

These names are reserved. Sending them manually is either rejected or double-counted.

Push notification permission

Web
App
TV / OTT

The operating system permission prompt.

Try it

Also store the answer as a user property (push_enabled) so audiences can use it.

Errors, performance, and experiments

Errors

Web
App
TV / OTT

Handled errors and failed requests that the user notices.

Try it

Keep description under 100 characters and free of user data; error messages often contain emails or IDs.
Apps report crashes through Crashlytics (app_exception); do not send them again.

Core Web Vitals

Web
App
TV / OTT

Real-user loading, responsiveness, and layout stability.

Try it

Uses the browser's own Largest Contentful Paint measurement.

Google's web-vitals example names the event after the metric (LCP, INP, CLS). A single web_vitals event with metric_name keeps them in one report; either works if you are consistent.
Report metric_value as a number (milliseconds; CLS is unitless) and register it as a custom metric.

A/B test exposure

Web
App
TV / OTT

Which variant of an experiment a user saw.

Try it

Firebase A/B Testing and most testing tools can send this for you; check before adding your own.

Games

Game progress and currency

Web
App
TV / OTT

Google's recommended events for games, used as-is.

Try it

Do not track

Personal data: Emails, names, phone numbers, street addresses, and free-text field values. Sending them breaks Google's terms and can force deletion of the property's data. This includes URLs that contain them.
Hover and pointer movement: Mouse moves, hovers, and tooltips showing. High volume, no intent.
Focus and keystrokes: Every key press, and every D-pad focus change on TV. Track the selection instead.
Automatic motion: Carousel autoplay, autoplaying previews, and timed rotations. Only user actions.
Heartbeats: An event every few seconds of playback. Use percent milestones.
The same event twice: An action already covered by enhanced measurement, sent again from GTM or code.
Unique values as dimensions: Timestamps, session IDs, or order IDs in parameters you report on. They create millions of rows that GA4 collapses into "(other)". BigQuery is the place for row-level IDs.

Event builder

Write an event for something this spec does not cover. It is checked against the same rules and converted for every platform.

Event name Parameters (JSON)

Event reference

Event	Type	Parameters	Used for
`add_payment_info`	Recommended	currency, value, payment_type, items	Product list to purchase
`add_shipping_info`	Recommended	currency, value, shipping_tier, items	Product list to purchase
`add_to_cart`	Recommended	currency, value, items	Product list to purchase
`add_to_wishlist`	Recommended	currency, value, items	Product list to purchase
`app_update`	Automatic	previous_app_version	Automatically collected app events
`audio_complete`	Custom	audio_title, audio_duration, audio_percent	Audio and podcasts
`audio_progress`	Custom	audio_title, audio_duration, audio_percent	Audio and podcasts
`audio_start`	Custom	audio_title, audio_duration, audio_percent	Audio and podcasts
`begin_checkout`	Recommended	currency, value, coupon, items	Product list to purchase
`carousel_slide`	Custom	carousel_name, slide_index, slide_name, method	Carousel
`cast_end`	Custom	cast_protocol, content_id	Casting and AirPlay
`cast_start`	Custom	cast_protocol, content_id	Casting and AirPlay
`click`	Enhanced measurement	link_url, link_domain, link_classes, link_id, outbound	Outbound link
`content_like`	Custom	content_type, content_id	Rate, like, save, and follow
`content_rate`	Custom	content_type, content_id, rating	Rate, like, save, and follow
`content_save`	Custom	content_type, content_id	Rate, like, save, and follow
`cta_click`	Custom	cta_text, cta_location, link_url	Call-to-action button
`earn_virtual_currency`	Recommended	virtual_currency_name, value	Game progress and currency
`exception`	Recommended	description, fatal	Errors
`experiment_view`	Custom	experiment_id, variant_id	A/B test exposure
`file_download`	Enhanced measurement	file_extension, file_name, link_text, link_url	File download
`file_upload`	Custom	upload_context, file_extension, file_size_kb	File upload
`filter_apply`	Custom	list_name, filter_name, filter_value	Filters and sorting
`first_open`	Automatic	—	Automatically collected app events
`form_error`	Custom	form_id, field_name, error_type	Form
`form_start`	Enhanced measurement	form_id, form_name, form_destination	Form
`form_submit`	Enhanced measurement	form_id, form_name, form_destination, form_submit_text	Form
`generate_lead`Key	Recommended	currency, value, lead_source	Form
`in_app_purchase`	Automatic	product_id, price, currency, quantity	Automatically collected app events
`join_group`	Recommended	group_id	Rate, like, save, and follow
`level_end`	Recommended	level_name, success	Game progress and currency
`level_start`	Recommended	level_name	Game progress and currency
`level_up`	Recommended	level, character	Game progress and currency
`load_more`	Custom	list_name, page_number	Pagination and "load more"
`login`	Recommended	method	Sign in and sign out
`logout`	Custom	—	Sign in and sign out
`modal_close`	Custom	modal_name, close_method	Modal dialog
`modal_view`	Custom	modal_name	Modal dialog
`nav_click`	Custom	link_text, link_url, nav_location	Menu, footer, and breadcrumb links
`notification_open`	Automatic	message_name	Automatically collected app events
`notification_permission`	Custom	permission_status, prompt_type	Push notification permission
`page_view`	Automatic	page_location, page_title, page_referrer	Page load; Single-page app route change
`paywall_view`	Custom	paywall_type, content_id	Paywall, trial, and subscription
`post_score`	Recommended	score, level, character	Game progress and currency
`purchase`Key	Recommended	transaction_id, currency, value, tax, shipping, coupon, items	Product list to purchase; Paywall, trial, and subscription
`refund`	Recommended	transaction_id, currency, value	Product list to purchase
`remove_from_cart`	Recommended	currency, value, items	Product list to purchase
`screen_view`	Automatic	screen_name, screen_class	App or TV screen; TV home rows and remote control
`scroll`	Enhanced measurement	percent_scrolled	Scroll depth
`search`	Recommended	search_term	Site and in-app search
`select_content`	Recommended	content_type, content_id, item_list_name, index	Tabs; Accordion and FAQ; Content card; TV home rows and remote control
`select_item`	Recommended	item_list_id, item_list_name, items	Product list to purchase
`select_promotion`	Recommended	promotion_id, promotion_name, creative_name, creative_slot	Promotion banner
`session_start`	Automatic	—	Automatically collected app events
`share`	Recommended	method, content_type, item_id	Share
`sign_up`Key	Recommended	method	Account creation
`sort_apply`	Custom	list_name, sort_by	Filters and sorting
`spend_virtual_currency`	Recommended	virtual_currency_name, value, item_name	Game progress and currency
`subscription_cancel`	Custom	plan_id, cancel_reason	Paywall, trial, and subscription
`trial_start`Key	Custom	plan_id, trial_days	Paywall, trial, and subscription
`tutorial_begin`	Recommended	—	Onboarding and tutorials
`tutorial_complete`	Recommended	—	Onboarding and tutorials
`unlock_achievement`	Recommended	achievement_id	Game progress and currency
`user_engagement`	Automatic	—	Automatically collected app events
`video_complete`	Enhanced measurement	video_provider, video_title, video_url, video_duration, video_current_time, video_percent, visible	Video player
`video_error`	Custom	video_provider, video_title, video_url, video_duration, error_code, video_current_time	Video player
`video_pause`	Custom	video_provider, video_title, video_url, video_duration, video_current_time, video_percent	Video player
`video_progress`	Enhanced measurement	video_provider, video_title, video_url, video_duration, video_current_time, video_percent, visible	Video player
`video_seek`	Custom	video_provider, video_title, video_url, video_duration, video_seek_from, video_seek_to	Video player
`video_start`	Enhanced measurement	video_provider, video_title, video_url, video_duration, video_current_time, video_percent, visible	Video player
`view_cart`	Recommended	currency, value, items	Product list to purchase
`view_item`	Recommended	currency, value, items	Product list to purchase
`view_item_list`	Recommended	item_list_id, item_list_name, items	Product list to purchase
`view_promotion`	Recommended	promotion_id, promotion_name, creative_name, creative_slot	Promotion banner
`view_search_results`	Enhanced measurement	search_term	Site and in-app search
`web_vitals`	Custom	metric_name, metric_value, metric_rating, metric_id	Core Web Vitals

Parameters

Parameter	Meaning	Events
`achievement_id`	Achievement ID.	unlock_achievement
`audio_duration`	Length in seconds.	audio_start, audio_progress, audio_complete
`audio_percent`	Percent listened milestone.	audio_start, audio_progress, audio_complete
`audio_title`	Episode or track title.	audio_start, audio_progress, audio_complete
`cancel_reason`	Reason chosen from a fixed list.	subscription_cancel
`carousel_name`	Which carousel.	carousel_slide
`cast_protocol`	chromecast or airplay.	cast_start, cast_end
`character`	Character used.	level_up, post_score
`close_method`	button, escape, backdrop, or action.	modal_close
`content_id`	Stable ID of the content. Not the title, which can change.	select_content, content_rate, content_like, content_save, paywall_view, cast_start, cast_end
`content_type`	Kind of thing selected: article, video, episode, tab, faq.	select_content, share, content_rate, content_like, content_save
`coupon`	Coupon code applied to the order.	begin_checkout, purchase
`creative_name`	Which creative version.	view_promotion, select_promotion
`creative_slot`	Where it was placed.	view_promotion, select_promotion
`cta_location`	Where on the page or screen.	cta_click
`cta_text`	Button label, in one language.	cta_click
`currency`	ISO 4217 code (USD, EUR). Required whenever value is sent.	generate_lead, view_item, add_to_wishlist, add_to_cart, remove_from_cart, view_cart, begin_checkout, add_shipping_info, add_payment_info, purchase, refund, in_app_purchase
`description`	Short error description, no user data.	exception
`error_code`	Player or platform error code.	video_error
`error_type`	Validation rule that failed (required, invalid_format).	form_error
`experiment_id`	Experiment key.	experiment_view
`fatal`	true if the app or page could not continue.	exception
`field_name`	Field that failed validation.	form_error
`file_extension`	Extension without the dot.	file_upload, file_download
`file_name`	Path of the downloaded file.	file_download
`file_size_kb`	Size in kilobytes.	file_upload
`filter_name`	Filter dimension (size, color, genre).	filter_apply
`filter_value`	Value chosen.	filter_apply
`form_destination`	Where the form posts.	form_start, form_submit
`form_id`	id attribute of the form.	form_start, form_error, form_submit
`form_name`	name attribute or a readable label.	form_start, form_submit
`form_submit_text`	Text of the submit button.	form_submit
`group_id`	ID of the group or topic.	join_group
`index`	Position in the list or row, zero-based.	select_content
`item_id`	ID of the shared item.	share
`item_list_id`	ID of the product list.	view_item_list, select_item
`item_list_name`	Readable name of the list or row.	view_item_list, select_item, select_content
`item_name`	Name of the item.	spend_virtual_currency
`items`	Array of products. Each needs item_id or item_name; up to 200 per event.	view_item_list, select_item, view_item, add_to_wishlist, add_to_cart, remove_from_cart, view_cart, begin_checkout, add_shipping_info, add_payment_info, purchase
`lead_source`	Where the lead came from.	generate_lead
`level`	Level number.	level_up, post_score
`level_name`	Level name.	level_start, level_end
`link_classes`	CSS classes on the link element.	click
`link_domain`	Destination domain (outbound links).	click
`link_id`	id attribute of the link element.	click
`link_text`	Visible text of the link or menu item.	nav_click, file_download
`link_url`	Destination URL or path.	nav_click, click, cta_click, file_download
`list_name`	Which list was refined.	filter_apply, sort_apply, load_more
`message_name`	Campaign name of the notification.	notification_open
`method`	How it happened: email, google, copy_link, arrow, swipe.	carousel_slide, sign_up, login, share
`metric_id`	Unique ID per page load, from web-vitals.	web_vitals
`metric_name`	LCP, INP, CLS, FCP, or TTFB.	web_vitals
`metric_rating`	good, needs-improvement, or poor.	web_vitals
`metric_value`	Metric value (ms, or unitless for CLS).	web_vitals
`modal_name`	Which dialog.	modal_view, modal_close
`nav_location`	Which menu: header, footer, breadcrumb, sidebar, tab_bar, side_menu.	nav_click
`outbound`	true when the link leaves your configured domains.	click
`page_location`	Full URL including query string. Max 1,000 characters.	page_view
`page_number`	Page of results now loaded.	load_more
`page_referrer`	Previous URL. Max 420 characters.	page_view
`page_title`	Document title. Max 300 characters.	page_view
`payment_type`	Payment method chosen.	add_payment_info
`paywall_type`	metered, hard, or registration.	paywall_view
`percent_scrolled`	Scroll depth threshold reached, as a number.	scroll
`permission_status`	granted or denied.	notification_permission
`plan_id`	Subscription plan.	trial_start, subscription_cancel
`previous_app_version`	Version before the update.	app_update
`price`	Unit price.	in_app_purchase
`product_id`	Store product ID.	in_app_purchase
`promotion_id`	Internal promotion ID.	view_promotion, select_promotion
`promotion_name`	Readable promotion name.	view_promotion, select_promotion
`prompt_type`	pre_permission or system.	notification_permission
`quantity`	Number of units.	in_app_purchase
`rating`	Number given (1 to 5).	content_rate
`score`	Score value.	post_score
`screen_class`	Class or component that rendered the screen.	screen_view
`screen_name`	Readable screen name you choose (Settings, Player).	screen_view
`search_term`	What was searched, lowercased and trimmed.	search, view_search_results
`shipping`	Shipping cost.	purchase
`shipping_tier`	Shipping option chosen.	add_shipping_info
`slide_index`	Zero-based slide position.	carousel_slide
`slide_name`	Slide label.	carousel_slide
`sort_by`	Sort order chosen.	sort_apply
`success`	Whether the level was completed.	level_end
`tax`	Tax amount.	purchase
`transaction_id`	Unique order ID. Deduplicates purchases.	purchase, refund
`trial_days`	Length of the trial.	trial_start
`upload_context`	What the file was for.	file_upload
`value`	Monetary value of the event, excluding tax and shipping.	generate_lead, view_item, add_to_wishlist, add_to_cart, remove_from_cart, view_cart, begin_checkout, add_shipping_info, add_payment_info, purchase, refund, earn_virtual_currency, spend_virtual_currency
`variant_id`	Variant shown.	experiment_view
`video_current_time`	Playhead position in seconds.	video_start, video_progress, video_complete, video_pause, video_error
`video_duration`	Length in seconds.	video_start, video_progress, video_complete, video_pause, video_seek, video_error
`video_percent`	Percent watched milestone.	video_start, video_progress, video_complete, video_pause
`video_provider`	Player or platform (youtube, html5, roku).	video_start, video_progress, video_complete, video_pause, video_seek, video_error
`video_seek_from`	Position before the seek, in seconds.	video_seek
`video_seek_to`	Position after the seek, in seconds.	video_seek
`video_title`	Title of the video.	video_start, video_progress, video_complete, video_pause, video_seek, video_error
`video_url`	Source or page URL.	video_start, video_progress, video_complete, video_pause, video_seek, video_error
`virtual_currency_name`	Currency name.	earn_virtual_currency, spend_virtual_currency
`visible`	Whether the player was on screen.	video_start, video_progress, video_complete