# Compare Batches — psiLynx

> Side-by-side comparison of two audit runs to identify regressions after deploys.

## Overview

The Compare tab lets you select any two completed check batches and see exactly how scores changed between them. Use it to verify a deploy improved things — or catch regressions before they affect users.

## Selecting batches

- **Before** — the baseline batch (older run).
- **After** — the comparison batch (newer run).

Both dropdowns show all completed batches with their date and time. Select any two to compare.

## Summary cards

After selecting batches, four summary cards appear at the top:

| Card | Description |
|---|---|
| **Avg Δ** | Average score change across all URLs (positive = improvement) |
| **Improved** | Number of URLs where scores went up |
| **Regressed** | Number of URLs where scores went down |
| **Unchanged** | Number of URLs with no score change |

## URL comparison table

Each row shows a URL with:

| Column | Contents |
|---|---|
| **URL** | Page path and label |
| **Before** | Mobile and Desktop scores from the baseline batch |
| **After** | Mobile and Desktop scores from the comparison batch |
| **Δ (Change)** | Score delta: green positive, red negative, grey unchanged |

Click a row to expand it and see the full Core Web Vitals breakdown.

## Expanded row — CWV detail

When a URL row is expanded, a detail panel shows per-metric changes:

- **LCP** — Before vs. After (mobile and desktop)
- **CLS** — Before vs. After
- **FCP** — Before vs. After
- **INP** — Before vs. After
- **TTFB** — Before vs. After

Each metric shows the before value, after value, and the difference with colour coding (green = improved, red = regressed).

> Compare is available on all plans. You need at least two completed check batches in the project to use this feature.