// open-source block explorers

Read the chain.Read the code.

Altscan is one open-source engine behind two independent explorers. Below, the blocks they are indexing right now. Further down, the code that indexes them.

Open BNBScan Open EthScan

Blocks being indexed right now

BNB Chainbnbscan.com —
Ethereumethscan.io —
width = block time · fill = gas used · replayed ~12s behind what each explorer has indexed blocks indexed since you arrived

// anatomy of a block

One real block,
taken apart.

ethereum · block

#—

hash
—
fee recipient
—
time
—
transactions
—
gas used
—

  1. Header

    Number, hash, who produced it and when, exactly as the chain recorded them.

    ethscan.io/blocks ↗

  2. Transactions

    Each with its receipt, logs and status. The receipts are checked against the block before anything is written.

    ethscan.io/txs ↗

  3. Gas

    How full the block ran, and what it cost to get in.

    ethscan.io/gas ↗

  4. What Altscan derives

    Token transfers, DEX trades, whale movements and webhooks, written from the receipts and safe to replay.

    ethscan.io/dex ↗

Every explorer also has address pages with token and NFT holdings, token pages, contract verification through Sourcify, network charts and a REST API with keys and webhooks.

// two explorers, live today

Same engine.
Each on its own domain.

BNBScan
bnbscan.com · BNB Chain
latest block
—
last 30 sec
—
status
—
Open explorer
EthScan
ethscan.io · Ethereum
latest block
—
last 30 sec
—
status
—
Open explorer

More chains are on the way, and each is announced on GitHub first.Watch the repo ↗

// read the code · AGPL-3.0

The whole engine,
to scale.

All 44,639 lines of TypeScript in its apps and packages are public: read them, fork them, run your own. Left to right, the code a block passes through, from its chain's entry in chain-config to the explorer page that shows it.

Star on GitHubSelf-host guide
width = lines of TypeScript · fill = share that is tests · counted 4 Oct 2026 browse the source ↗
  1. chain-config 514
  2. providers 2,433
  3. indexer 15,206
  4. db 721
  5. explorer-core 512
  6. explorer 20,324
  1. admin 2,703
  2. altscan-site 1,005 (this page)
  3. status 488
  4. settings-schema 628
  5. types 105

// or run your own

Postgres, Redis, the indexer and an explorer, from the repository's compose file. No configuration to start.

git clone https://github.com/heathermhuang/altscancd altscan && cp .env.docker.example .envdocker compose up -d