DFlight API vs National Grid ESO

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

Uptime · 30d
Uptime · 90d11.8%100%
Uptime · 30d0.0%100%
P50 · ms319609
P95 · ms6681311
Authnonenone
CORSnoyes
HTTPSyesyes
Card requirednono
Commercial useunclearunclear
Data licenseUnverifiedNESO Open Data Licence (OGL-based); varies per dataset
Free tierFree — limits not publishedFree — limits not published
Rate limitUnpublishedUnpublished
In directory since2026-07-052026-07-05
operationalpartialdownno data

DFlight API vs National Grid ESO: common questions

Which is more reliable, DFlight API or National Grid ESO?

On our scheduled checks, National Grid ESO leads on measured uptime — DFlight API at 11.8% 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, DFlight API or National Grid ESO?

DFlight API has the lower median latency in our checks — DFlight API responds in 319 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 DFlight API and National Grid ESO need an API key?

Neither needs a paid key — DFlight API 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 DFlight API and National Grid ESO from the browser?

Only National Grid ESO is browser-friendly — it returns CORS headers over HTTPS. DFlight API needs a server-side call or proxy, so factor that into which one fits a front-end project.

Are DFlight API and National Grid ESO free for commercial use?

DFlight API 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.