---
title: 'Core Web Vitals Regression Triage for Busy Teams'
description: 'A practical, plain-language guide to finding and fixing Core Web Vitals regressions with KaBOOM Agentic Devtools.'
canonical: https://gokaboom.dev/articles/core-web-vitals-regression-triage/
docs_version: 'v0.8.1'
docs_channel: 'latest'
last_verified_version: '0.8.0'
last_verified_date: 'Fri Mar 06 2026 00:00:00 GMT+0000 (Coordinated Universal Time)'
normalized_tags: ['performance', 'web-vitals', 'bug-triage', 'debugging', 'articles', 'core', 'web', 'vitals', 'regression']
related_guides: ['/guides/debug-webapps/', '/guides/api-validation/', '/reference/observe/']
---

When pages feel slower after a release, users notice before dashboards do.

**Core Web Vitals** are user-centered performance metrics from Google, including Largest Contentful Paint, Interaction to Next Paint, and Cumulative Layout Shift. https://web.dev/articles/vitals

Let’s triage regressions quickly with **KaBOOM Agentic Devtools**.

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## Quick Terms

- **Largest Contentful Paint (LCP)**: How quickly main content appears.
- **Interaction to Next Paint (INP)**: How responsive the page feels during interaction.
- **Cumulative Layout Shift (CLS)**: Visual stability (how much content jumps around).

## The Problem You Are Solving

You need to answer:

“What changed, where did it regress, and what fix gives fastest impact?”

## Step-by-Step with KaBOOM Agentic Devtools

### Step 1. Capture current vitals

```js
observe({what: "vitals"})
```

### Step 2. Run performance analysis

```js
analyze({what: "performance", summary: true})
```

### Step 3. Identify risky resources

```js
observe({what: "network_waterfall", limit: 100})
```

### Step 4. Compare before and after fix

```js
configure({what: "recording_start"})
// run key interaction flow
configure({what: "recording_stop", recording_id: "rec-perf-after"})
configure({what: "log_diff", original_id: "rec-perf-before", replay_id: "rec-perf-after"})
```

## Fast Prioritization Rule

1. Fix high LCP blockers first (hero image, render-blocking scripts).
2. Fix INP next (heavy event handlers).
3. Fix CLS by reserving space for dynamic content.

## Image and Diagram Callouts

> [Image Idea] Mini dashboard showing LCP/INP/CLS before and after.

> [Diagram Idea] “Impact ladder” mapping each fix to expected user-perceived improvement.

## You’re Doing Performance Like a Pro

Performance triage is not about perfection in one day. It is about high-impact steps in the right order. **KaBOOM Agentic Devtools** helps you do exactly that.