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Cardano Address Reader

ADA balance, UTxO count, and stake info — via the free Koios API, keyless and client-side

Address lookup (mainnet)

Queries use the free public Koios API directly from your browser - no key, no signup, nothing logged here. Cardano smart contracts (Plutus) run validation on-chain rather than exposing readable view functions, so on-chain scripts are inspected via transaction datums and redeemers on explorers.

About the Cardano Reader

Cardano tracks every address in the eUTxO model: an address holds unspent outputs, and its balance is their sum. Checking a balance, a stake delegation, or a UTxO count is a read-only query that public indexers answer for free.

Paste any Shelley address (addr1...) to read its ADA balance, UTxO count, script status, and associated stake address from Koios - a free, keyless public API. Queries go directly from your browser; nothing is logged here.

How to use

  1. Paste a Cardano mainnet address (starts with addr1).
  2. Read the ADA balance, UTxO count, and stake address.
  3. Copy the stake address to check delegation in any pool explorer.
  4. Script addresses (Plutus) are flagged automatically.

Frequently Asked Questions

Does this need an API key? ▾

No. It queries Koios, a free public Cardano indexer with no registration. Requests go directly from your browser to the Koios API.

Can I read Cardano smart contracts like EVM view functions? ▾

Not directly - Plutus scripts validate transactions rather than expose callable views. On-chain state is inspected via transaction datums and redeemers; this reader covers addresses, balances, and UTxOs.

Why does the balance show zero for a stake address? ▾

This tool queries payment addresses (addr1...). Rewards on stake addresses (stake1...) are viewed in wallet apps or stake explorers, though the linked stake address is shown here when one exists.

Is this tool free to use? ▾

Yes! This tool is 100% free. No signup, no credit card, no limits. It's part of Formatho's privacy-first developer toolkit.

Is my data safe? Does this tool send data to a server? ▾

Absolutely. This tool runs entirely in your browser. Your data never leaves your device. Zero server-side processing, zero tracking.