> ## Documentation Index
> Fetch the complete documentation index at: https://docs.sitespy.app/llms.txt
> Use this file to discover all available pages before exploring further.

# Timeline and Diff

> View change history and compare snapshots

Site Spy captures snapshots of your watched pages every time it checks for changes. You can view these snapshots and compare them in two ways.

## Diff

Diff compares the **two most recent snapshots** of a watched page.

1. Click the **diff icon** (split-screen icon) on any watch in the extension popup
2. Site Spy triggers a fresh recheck on the server and waits a few seconds
3. The diff view opens showing what changed between the last two snapshots

**Best for:** Seeing what changed since the previous check.

### Reading the diff

* **Green highlights** = content that was added
* **Red highlights** = content that was removed

## Timeline

Timeline lets you browse **all historical snapshots** and compare any two.

1. Click the **timeline icon** (clock icon) on any watch (requires at least 2 snapshots)
2. Browse snapshots with timestamps
3. Select any two snapshots to compare side by side

**Best for:** Tracking changes over time and comparing specific points in history.

> Snapshots are created each time the server checks the site. Wait for the next scheduled check or trigger a manual recheck to create more snapshots.

## Preview

Preview shows the most recent snapshot as a rendered page, so you can see what the page looked like at the time of capture.

## Tips

* Use **Diff** for "what changed since last check" comparisons
* Use **Timeline** for historical analysis across multiple snapshots
* All content checking happens on the monitoring server for accuracy
* Use element monitoring to ignore dynamic content like ads or timestamps