The software matters more than the website
Blockstream.info is a public instance of Esplora, which Blockstream publishes as open source. That distinction is the whole review. The website is a convenience; Esplora is infrastructure, and a substantial share of the Bitcoin tooling you use has an Esplora-compatible API somewhere in its dependency graph.
The reason it spread is that the API shape is sensible and the licence permits use. mempool.space implements a compatible surface, which means code written against one works against the other with a base-URL change. For anyone building something that needs a fallback source, that compatibility is worth a great deal — you get redundancy without writing an adapter layer.
It also means the data model is transparent. You can read exactly how an address balance is computed, which is not a rhetorical point: explorers disagree about balances more often than people expect, usually over how unconfirmed outputs are counted, and being able to read the code settles the argument rather than prolonging it.
The API: still genuinely free
We tested this before writing anything about it. A cold request from a clean machine, no key, no headers, no account:
curl https://blockstream.info/api/blocks/tip/height
967384That is the whole ceremony. In a landscape where Etherscan and Blockscout now both require registration even to use their free tiers, a genuinely keyless endpoint has become unusual enough to be worth stating plainly.
The endpoints follow an obvious pattern. /address/:address returns funded and spent totals plus transaction counts, separated into confirmed and mempool. /tx/:txid returns the full transaction. /block/:hash and /block-height/:height handle blocks. /fee-estimates returns a map of confirmation targets to fee rates. Amounts are always in satoshis, integers throughout, which removes an entire category of floating-point bug.
Testnet and signet on the same shape
Prefix the path and you get a different network: /testnet/api/, /signet/api/, /liquid/api/. Same endpoints, same responses. For development this is the single most practical feature here — you can build against signet, flip one string, and be on mainnet with no other change.
It works from a browser
The API sends permissive CORS headers, so it can be called directly from front-end code with no server in between. The lookup tool on this site uses it for exactly that reason. A keyed API cannot do this without exposing the key, which is the constraint that quietly rules out most competitors for static sites and browser extensions.
Liquid, and the limits of what an explorer can show
Liquid is a Bitcoin sidechain operated by a federation, with faster settlement and — importantly here — Confidential Transactions, which hide amounts and asset types from everyone except the participants.
Blockstream.info is one of very few explorers with proper Liquid support, which makes sense given who runs it. What is instructive is how it handles the confidentiality. Rather than showing zeros or omitting fields, it shows the transaction structure and marks the amounts as blinded. You can see that value moved and you cannot see how much.
This is the honest behaviour, and it is worth internalising because the same situation arises on Monero and inside Litecoin's MWEB. An explorer showing a blank where you expected a number is usually working correctly. An explorer showing a confident number where the data is cryptographically hidden is showing you a guess.
The austerity is a choice, and it costs you
Being fair about the downside: this is a plain tool and the plainness has real costs.
There is no fee-market visualisation. If your transaction is stuck, Blockstream.info will tell you it is unconfirmed and stop. It will not tell you where you sit in the queue, what rate is currently clearing, or whether waiting is sensible. That is mempool.space's job and the gap is not close.
There is no address labelling. Every address is a string. Whether it belongs to a major exchange or to your neighbour, the page looks identical. For most purposes that is fine and arguably correct; for anyone trying to understand a flow it means considerable manual work.
And there is almost no historical charting. Difficulty over time, hash rate, transaction volume trends — none of it. Blockchair and BitInfoCharts cover that ground.
Why this still scores well
Our weighting rewards API access and privacy heavily, and Blockstream.info is close to perfect on both. It also rewards depth, where it is merely adequate. The result is an explorer that lands high on the list for reasons that have almost nothing to do with the website itself — which is the correct outcome, because the website is not the point.
Running Esplora yourself
This is where Esplora earns its place. Blockstream publishes the source and the documentation, and of the credible options it is the most straightforward Bitcoin explorer to stand up.
You need a Bitcoin Core node with txindex enabled, which pushes storage comfortably past 700 GB, and you want SSD. The Esplora indexer builds its own database on top, adding meaningfully to that. Initial sync and index construction takes days, not hours. Nobody should pretend otherwise.
What you get in return is total independence. No rate limits, no key, no operator learning which addresses you care about, and no outage that is not yours. If you run a Bitcoin node for any other reason, adding Esplora is the obvious next step, and the API you get is the same one this site queries. Our self-hosting guide puts the disk, memory and time costs side by side against the alternatives.