---
title: Verify Browser Unified SDK events
description: "Check that the Browser Unified SDK initialized each product, then trace an analytics event from capture to Amplitude with the Browser SDK 2 verification steps."
product: analytics
lang: en
last_updated: 2026-10-29
token_estimate: 1100
---
# Verify Browser Unified SDK events

> For AI agents: a documentation index is available at [/docs/llms.txt](/docs/llms.txt). Append `.md` to any page URL for markdown, or send `Accept: text/markdown`.

The Browser Unified SDK sends analytics events through the bundled Browser SDK 2. An analytics event moves through the same four stages as in Browser SDK 2: captured, transformed, sent, and received. This page covers the checks specific to the Unified SDK, starting with initialization, and links to the Browser SDK 2 steps for the other stages.

| Stage | Question | Where to look |
| --- | --- | --- |
| [Initialized](#check-that-each-product-initialized) | Did `initAll()` set up every product you use? | The accessors and the browser **Network** tab |
| Captured | Did the SDK accept the call? | [Debug logs](https://amplitude.com/docs/sdks/analytics/browser/browser-sdk-2/verify-events#check-what-the-sdk-captured) |
| Transformed | What did plugins add, change, or drop? | [An inspection plugin](https://amplitude.com/docs/sdks/analytics/browser/browser-sdk-2/verify-events#check-how-plugins-transformed-the-event) |
| [Sent](#check-what-the-sdk-sent) | Did the request leave the browser, and with what payload? | The browser **Network** tab |
| Received | Did Amplitude accept and store the event? | [The upload result and User Lookup](https://amplitude.com/docs/sdks/analytics/browser/browser-sdk-2/verify-events#check-what-amplitude-received) |

For problems common to every Amplitude SDK, go to [SDK troubleshooting and debugging](https://amplitude.com/docs/sdks/sdk-debugging). For changes between versions, go to the [`@amplitude/unified` changelog](https://github.com/amplitude/Amplitude-TypeScript/blob/main/packages/unified/CHANGELOG.md).

## Turn on debug logging

Pass `logLevel` inside `analytics`. Session Replay logs through the same logger, so its messages appear with the analytics messages.

```ts
amplitude.initAll("YOUR_API_KEY", {
  analytics: { logLevel: amplitude.Types.LogLevel.Debug },
});
```

For log levels and what each message contains, go to [Turn on debug logging](https://amplitude.com/docs/sdks/analytics/browser/browser-sdk-2/verify-events#turn-on-debug-logging) in Browser SDK 2. Return `logLevel` to `Warn` before you ship.

## Check that each product initialized

Await `initAll()`, then check each product through its accessor:

```ts
await amplitude.initAll("YOUR_API_KEY", {
  sessionReplay: { sampleRate: 1 },
});

console.log(amplitude.sessionReplay()?.getSessionReplayProperties());
// { "[Amplitude] Session Replay ID": "..." } while recording; {} when not

console.log(typeof amplitude.experiment()?.fetch);
// "function"
```

In the browser **Network** tab, filter on `amplitude.com` and look for these requests:

| Product | Request | When |
| --- | --- | --- |
| Session Replay | `sr-client-cfg.amplitude.com/config/<API key>` (`sr-client-cfg.eu.amplitude.com` for EU) | During `initAll()` |
| Session Replay | `api-sr.amplitude.com/sessions/v2/track` (`api-sr.eu.amplitude.com` for EU) | While a session records |
| Feature Experiment | `api.lab.amplitude.com/sdk/v2/vardata` (`api.lab.eu.amplitude.com` for EU) | Only after you call `fetch()` |
| Guides and Surveys | `cdn.amplitude.com/engagement-browser/...`, then `gs.amplitude.com/sdk/v1/...` | During `initAll()`, unless `skip` |

If `getSessionReplayProperties()` returns `{}`, Session Replay isn't recording. Check the log for this message: `Session ... not being captured due to capture being disabled for project or because the remote config could not be fetched.` Then confirm that `sampleRate` is above `0`.

## Check what the SDK sent

Find the request to `api2.amplitude.com/2/httpapi` (`api.eu.amplitude.com` for EU) and open its payload. The `library` field of each Unified SDK event contains two version numbers:

```json
{
  "event_type": "Sign Up Clicked",
  "library": "amplitude-ts-unified/1.1.43-amplitude-ts/2.48.1"
}
```

The first version is `@amplitude/unified`. The second is the bundled Browser SDK 2. Use the second version when you compare behavior against the [Browser SDK 2 release notes](https://amplitude.com/docs/sdks/analytics/browser/browser-sdk-2-release-notes). For payload fields and compression, go to [Check what the SDK sent](https://amplitude.com/docs/sdks/analytics/browser/browser-sdk-2/verify-events#check-what-the-sdk-sent) in Browser SDK 2.