BlockCypher vs Mempool

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

Uptime · 30d
Uptime · 90d—%—%
Uptime · 30d—%—%
P50 · ms
P95 · ms
Authnonenone
CORSnoyes
HTTPSyesyes
Card requirednono
Commercial useunclearunclear
Data licenseUnverifiedUnverified (open-source project)
Free tierFree — limits not publishedFree public API; no key for basic usage
Rate limitRetry-After: 1787sEnforced — HTTP 429 on excess, repeated abuse may be banned; numeric limits unpublished
In directory since2026-07-052026-07-05
operationalpartialdownno data

BlockCypher vs Mempool: common questions

Which is more reliable, BlockCypher or Mempool?

On our scheduled checks, Mempool leads on measured uptime — BlockCypher at —% versus Mempool at —% over 90 days. These are our own probe results, not provider claims; the uptime bars above show the day-by-day record for both.

Do BlockCypher and Mempool need an API key?

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

Can I call BlockCypher and Mempool from the browser?

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

Are BlockCypher and Mempool free for commercial use?

BlockCypher has unclear commercial terms, and Mempool 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.