Blockchair vs Kraken
Same instrument, two spec sheets — measured, not claimed.
Blockchair vs Kraken: common questions
Which is more reliable, Blockchair or Kraken?
On our scheduled checks, Kraken leads on measured uptime — Blockchair at 98.0% versus Kraken 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, Blockchair or Kraken?
Kraken has the lower median latency in our checks — Blockchair responds in 729 ms versus Kraken at 155 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 Blockchair and Kraken need an API key?
Neither needs a paid key — Blockchair is callable with no signup, and Kraken is callable with no signup. Both are quick to prototype with; rate limits still apply.
Can I call Blockchair and Kraken from the browser?
Yes — both Blockchair and Kraken 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 Blockchair and Kraken free for commercial use?
Blockchair has unclear commercial terms, and Kraken 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.