GrünstromIndex vs National Grid ESO

Same instrument, two spec sheets — measured, not claimed.

Uptime · 30d
Uptime · 90d73.5%100%
Uptime · 30d73.3%100%
P50 · ms1072609
P95 · ms41191311
Authnonenone
CORSyesyes
HTTPSyesyes
Card requirednono
Commercial useunclearunclear
Data licenseUnverifiedNESO Open Data Licence (OGL-based); varies per dataset
Free tierFree under fair-use policyFree — limits not published
Rate limitFair-use (paid tiers for higher limits)Unpublished
In directory since2026-07-052026-07-05
operationalpartialdownno data

GrünstromIndex vs National Grid ESO: common questions

Which is more reliable, GrünstromIndex or National Grid ESO?

On our scheduled checks, National Grid ESO leads on measured uptime — GrünstromIndex at 73.5% versus National Grid ESO 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, GrünstromIndex or National Grid ESO?

National Grid ESO has the lower median latency in our checks — GrünstromIndex responds in 1072 ms versus National Grid ESO at 609 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 GrünstromIndex and National Grid ESO need an API key?

Neither needs a paid key — GrünstromIndex is callable with no signup, and National Grid ESO is callable with no signup. Both are quick to prototype with; rate limits still apply.

Can I call GrünstromIndex and National Grid ESO from the browser?

Yes — both GrünstromIndex and National Grid ESO 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 GrünstromIndex and National Grid ESO free for commercial use?

GrünstromIndex has unclear commercial terms, and National Grid ESO 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.