The baseline snapshot is your reference image — the "correct" version of your page that all future screenshots are compared against.
How it works
When NerdTools captures a new screenshot, it compares it to your baseline using visual comparison algorithms. If the difference exceeds your tolerance threshold, you'll be notified of a change.
Setting your baseline
- After verification, wait for your first screenshot to be captured.
- Review the captured image to ensure it looks correct.
- Click the "Set as baseline" button on the snapshot you want to use.
Updating your baseline
When you intentionally make changes to your page (redesigns, content updates, etc.), you should update your baseline:
- Wait for a new screenshot that shows your updated page.
- Review it to confirm the changes are correct.
- Set the new snapshot as your baseline.
You can select any of your recent snapshots to use as the baseline — it doesn't have to be the most recent one.