arcsecond.io vs TLE

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

Uptime · 30d
Uptime · 90d100%88.2%
Uptime · 30d100%80.0%
P50 · ms5871090
P95 · ms15782424
Authnonenone
CORSyesyes
HTTPSyesyes
Card requirednono
Commercial useunclearunclear
Data licenseUnverifiedUnverified
Free tierFree — limits not publishedFree — limits not published
Rate limitUnpublishedRetry-After: 14400s
In directory since2026-07-052026-07-05
operationalpartialdownno data

arcsecond.io vs TLE: common questions

Which is more reliable, arcsecond.io or TLE?

On our scheduled checks, arcsecond.io leads on measured uptime — arcsecond.io at 100% versus TLE at 88.2% 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, arcsecond.io or TLE?

arcsecond.io has the lower median latency in our checks — arcsecond.io responds in 587 ms versus TLE at 1090 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 arcsecond.io and TLE need an API key?

Neither needs a paid key — arcsecond.io is callable with no signup, and TLE is callable with no signup. Both are quick to prototype with; rate limits still apply.

Can I call arcsecond.io and TLE from the browser?

Yes — both arcsecond.io and TLE 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 arcsecond.io and TLE free for commercial use?

arcsecond.io has unclear commercial terms, and TLE 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.