Before you save a scraper, Trawley shows you a preview of the data it would capture from the real page. Validating here is the difference between a scraper that just works and one you have to fix after its first run.
The preview
As you build, the assistant pulls a sample of real results and shows them with your fields as columns. You see actual values, not placeholders, so you can spot problems immediately.
What to check
Every field has a value
Scan for empty columns. A field that is blank across the preview is mapped to the wrong place. Tell the assistant and it will re-map it.
Values look right
Check that prices are numbers, dates are dates, and text is the intended text.
A price showing Offers over £400,000 may need cleaning to a plain number.
The right number of items
If the page shows 24 listings and the preview has 12, pagination or the item selector needs attention.
Fixing problems
Every problem is fixed by describing it in the chat. "The bedrooms field is empty", "only the first page is showing", or "the price includes the currency symbol" all give the assistant enough to correct the configuration and refresh the preview.
Validate against an item you know well. Pick a listing you can open yourself, then confirm Trawley captured the same values you see.