Open Topo Data vs Postcodes.io
Same instrument, two spec sheets — measured, not claimed.
Open Topo Data vs Postcodes.io: common questions
Which is more reliable, Open Topo Data or Postcodes.io?
On our scheduled checks, Postcodes.io leads on measured uptime — Open Topo Data at 93.1% versus Postcodes.io at 100% over 90 days. These are our own probe results, not provider claims; the uptime bars above show the day-by-day record for both.
Which is faster, Open Topo Data or Postcodes.io?
Postcodes.io has the lower median latency in our checks — Open Topo Data responds in 285 ms versus Postcodes.io at 33 ms (P50). Tail latency (P95) is in the table above; for most workloads the median is the number that shapes how the API feels.
Do Open Topo Data and Postcodes.io need an API key?
Neither needs a paid key — Open Topo Data is callable with no signup, and Postcodes.io is callable with no signup. Both are quick to prototype with; rate limits still apply.
Can I call Open Topo Data and Postcodes.io from the browser?
Only Postcodes.io is browser-friendly — it returns CORS headers over HTTPS. Open Topo Data needs a server-side call or proxy, so factor that into which one fits a front-end project.
Are Open Topo Data and Postcodes.io free for commercial use?
Open Topo Data has unclear commercial terms, and Postcodes.io has unclear commercial terms. We track service terms and the data license as separate fields — see the Commercial use and Data license rows above, and confirm both before shipping either in a paid product.