Blockchair API
Multi-blockchain explorer API supporting 17+ blockchains including Bitcoin, Ethereum, and Cardano with SQL-like queries.
🟢 Online · 2316 ms
72.4%
1,430 calls/day, no key (key extends limits)
No key required
Free alternatives (live ranking)
- Kraken Public API — 🟢 Online · Unlimited public data, no key required
- Coinbase Advanced Trade API (Public) — 🟢 Online · 10 calls/sec, no key for public endpoints
- Blockchain.com Data API — 🟢 Online · Unlimited, no key, no credit card
Compare Blockchair API with…
- Blockchair API vs Kraken Public API — Unlimited public data, no key required
- Blockchair API vs Coinbase Advanced Trade API (Public) — 10 calls/sec, no key for public endpoints
- Blockchair API vs Blockchain.com Data API — Unlimited, no key, no credit card
Paid alternatives
- Blockchair Starter — from $225/mo
Frequently Asked Questions
Does Blockchair API require an API key?
No, Blockchair API is freely accessible without registration or an API key.
What is Blockchair API's free tier?
1,430 calls/day, no key (key extends limits)
Is Blockchair API currently online?
We check Blockchair API every hour. The current status is shown at the top of this page. You can also see the 30-day uptime history in the chart above.
Implementation notes
When to use Blockchair API
Blockchair supports 17+ blockchains with a SQL-like query interface, making it the best free option for cross-chain analytics. The free tier provides 1,430 calls/day without a key, and the query DSL lets you filter transactions by amount, date, address type, or fee range — features absent from single-chain APIs.
Common pitfalls
- 1,430 calls/day (roughly 1 call per minute) is sufficient for dashboards and research tools but too slow for wallets needing real-time updates. Registering a free API key raises the soft limit and makes debugging easier via the dashboard.
- Blockchair's SQL-like query filters are powerful but have strict syntax. A missing quote around a string value or an unsupported operator returns a 400 with a generic 'Bad request' message rather than a parse error. Test queries in the Blockchair web explorer first.
- The response schema for transactions differs between blockchains. Bitcoin transactions include `input_total`, `output_total`, and `fee`; Ethereum transactions include `value`, `gas_used`, and `gas_price`. Do not assume a common schema across chains.
- Privacy features (address clustering, entity labelling) are paid-only. The free tier does not return these fields, but the API includes them as `null` placeholders in the response rather than omitting them — guard against null pointer errors.
Quick start (bash)
curl "https://api.blockchair.com/bitcoin/stats"Embed this badge
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Markdown
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<a href="https://freeapi.watch/blockchair"><img src="https://freeapi-builder.a10ayassine.workers.dev/badge/blockchair.svg" alt="Blockchair API Status"/></a>