EPA vs Federal Register
Same instrument, two spec sheets — measured, not claimed.
EPA vs Federal Register: common questions
Which is more reliable, EPA or Federal Register?
On our scheduled checks, Federal Register leads on measured uptime — EPA at 54.9% versus Federal Register at 98.0% 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, EPA or Federal Register?
Federal Register has the lower median latency in our checks — EPA responds in 3150 ms versus Federal Register at 478 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 EPA and Federal Register need an API key?
Neither needs a paid key — EPA is callable with no signup, and Federal Register is callable with no signup. Both are quick to prototype with; rate limits still apply.
Can I call EPA and Federal Register from the browser?
Yes — both EPA and Federal Register send CORS headers over HTTPS, so front-end code can fetch either directly with no backend proxy. That makes them easy to swap in a client-side app while you compare responses.
Are EPA and Federal Register free for commercial use?
EPA has unclear commercial terms, and Federal Register allows commercial use on its free tier. 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.