SEO best practice for page that is the same for 50 US States


I have a calculator for each US state: for example let’s say you plug in your income and it tells you your state tax rate, which depends on your state.

The calculator has the same UI for ever state, one simple form. The only difference is the page title and H1 tag "PA Tax Calculator" and "Pennsylvania Tax Rates." Of course, your results depend on the state which is generated using JS.

I am trying to decide between:

  • 50 Unique URLs that I send to Google: example.com/calc/?state=PA and example.com/calc/?state=CA, then state-specific titles on Google: "PA Tax Calculator"
  • One URL for indexing (example.com/calc/) that then uses a select form or geolocation to select the correct state. Leave the Google page title generic: "50 State Tax Calculator"

I’d like to be able to put the state title in the Google search title as I think it would feel more personal for vistors, but it seems like if the 50 pages are too similar it’ll just be diluting to have 50 identical pages. This is my first time trying to figure out how to get visitors via SEO.