Google Trends has two limits that come up the moment you use it for real work:

You can compare at most 5 terms at once.

For any range longer than about 9 months , you get weekly or monthly points, not daily ones.

Both limits have the same cause, and the same fix. Every response from Google is scaled 0-100 against its own peak. A "50" in one request and a "50" in another mean nothing relative to each other. You can still join requests, though, as long as they share something you can measure in both. Then you rescale one to match the other.

I spent a while getting this right for a scraper I built. Here's what works and what doesn't.

Comparing more than 5 keywords

The usual advice is to put one anchor keyword in every batch of 5 and rescale each batch by the anchor's total. It works until your keywords have very different sizes.

Google rounds every value to a whole number. Compare "coffee" with "kombucha" and kombucha comes back as 0 or 1 on most days, so most of its signal is lost.…