Guide 197 · Events · GA4 + Tag Manager
The GA4 event limits reference: 25 parameters, 40-character names, and the 100,000-a-day ceiling
GA4 drops what exceeds its collection limits and refuses what exceeds its configuration limits — 25 parameters per event, 40-character names, 100,000 events per user per day.
After step 5, you can audit any property against the two tables — collection limits and configuration limits — and name the headroom on key events, audiences, and custom dimensions.
Download the reference: the GA4 event limits reference (JSON) (2270 bytes, MD5 55174251fe11cb90e5b2aa3e2a92c70e). It holds the report or event definition and the worked example with the recomputed figures shown on this page.
What you need
- The event collection limits page in Analytics Help — the limits enforced when data is collected, per property.
- The configuration limits page beside it — the limits enforced when you configure an item in the interface, per property.
- The knowledge that the two tables bite differently. Over a collection limit, the data is not logged. Over a configuration limit, the item cannot be created.
The trace
- Read the collection limits first. These apply on a per-property basis. There is no limit on the number of distinctly named events for web data streams; app streams allow 500 distinctly named events per app user. A user is capped at 2,000 distinct sessions per day, 10,000 conversions per day, and 100,000 events per day. An event name may be 40 characters. An event may carry 25 event parameters, and an ecommerce event may carry up to 27 item-level custom parameters on top of its prescribed item parameters.
- Read the character limits inside the same table. An event parameter name may be 40 characters, and a parameter value may be 100 characters, with three exceptions: page_title may be 300 characters or fewer, page_referrer 420 or fewer, and page_location 1,000 or fewer. User properties are capped at 25 per property, their names at 24 characters and their values at 36, and a User-ID value at 256 characters. The worked example below audits a property against these numbers.
- Read the configuration limits next. A standard property allows 100 audiences, 50 saved comparisons, 50 saved segments, 30 key events, 50 custom insights, 25 user-scoped custom dimensions, 50 event-scoped custom dimensions and 50 event-scoped custom metrics. Data export is capped at 100,000 rows for reports and explorations, and data retention runs up to 14 months. The Ads links ceiling is 400 per property.
- Check what archiving frees. The tables carry a column for whether you can archive items when you are close to a limit. Key events, audiences, custom insights, and all three custom-dimension scopes can be archived. The 26th user property cannot be archived into existence — user properties cannot be archived at all, so the 26th is simply not processed. Saved comparisons and saved segments cannot be archived either.
- Know what 360 changes and what it does not. You can increase certain limits by upgrading to Google Analytics 360, but not the event and parameter character limits. A name over 40 characters is not processed on any plan.
Dead ends
DEAD END — ASSUMING AN OVER-LIMIT EVENT ARRIVES ANYWAY. Google Analytics does not log events, event parameters, and user properties that exceed the collection limits. The 26th parameter on an event and the 26th user property are not stored truncated — they are not processed at all. If a value is missing downstream, count the parameters first.
DEAD END — MARKING A LONG EVENT NAME AS A KEY EVENT. If you mark an event as a key event and the event name exceeds 40 characters, the event will not be reported as a key event, because the appended key-event marker will be missing. The name has to fit inside 40 characters before the star means anything.
DEAD END — READING THE CONFIGURATION TABLE AS A COLLECTION TABLE. The two tables answer different questions. A property at 30 key events can still collect the events themselves — the configuration limit blocks creating the 31st key event, not the 100,001st event. Check the right table for the failure you are seeing.
End state
The limits are the shape of the property: they decide what arrives, what can be configured, and what has to wait for 360. The worked example below audits one property against both tables.
Worked example — stated inputs, recomputed results. A property is audited against the two limit tables. Every overage and every remaining slot below is recomputed.
| Check | Count | Limit | Result |
|---|---|---|---|
| Parameters on one event | 27 | 25 | 2 over — dropped |
| Event name length | 41 characters | 40 | 1 over — not processed |
| User properties | 26 | 25 | 26th not processed |
| Key events | 23 | 30 | 7 slots left |
| Audiences | 100 | 100 | 0 slots left |
27 − 25 = 2 parameters over the cap. 41 − 40 = 1 character over the name cap. 30 − 23 = 7 key-event slots left, and 100 − 100 = 0 audience slots left.
Sources
- Analytics Help — Event collection limits — the per-property collection limits: 100,000 events, 2,000 sessions and 10,000 conversions per user per day, 25 parameters per event, 27 item-level custom parameters, and the 40/100/300/420/1,000 character limits
- Analytics Help — [GA4] Configuration limits — the per-property configuration limits: 30 key events, 100 audiences, 50 event-scoped custom dimensions, 50 event-scoped custom metrics, 25 user-scoped custom dimensions, the 400 Ads links ceiling, and which items can be archived
Checked 11 November 2026. The click paths above are the ones in Google's help and developer pages, opened in full on 11 November 2026. No step in this guide was run inside a live Analytics property, because that needs a Google sign-in and this site does not sign in as anyone. The worked-example figures on this page were recomputed in Python with decimal arithmetic, and the downloadable JSON file carries the same recomputed figures. Google moves menu items without warning; if a path on this page no longer matches, the linked help page is the current map.