Blockchain — entry 005 of 11
Etherscan
Etherscan's API exposes the same account balances, transactions, contract source, and gas-tracker data shown on the block explorer, addressed to Ethereum mainnet and its testnets through a single query-parameter-based endpoint. Calls against the older V1 endpoint now return a deprecation notice pointing at the documented V2 migration, so new integrations should build against V2 directly. Free-tier keys cover light use, with paid plans unlocking higher rate limits.
AuthenticationAPI KeySign up with the provider to obtain credentials.
HTTPSSupportedTraffic is encrypted in transit.
CORSEnabledCallable directly from browser JavaScript.
PricingFreemiumA usable free tier exists, with paid plans for more volume.
FormatsJSONResponses can be requested as JSON.
GreatAPIs Score
Score75
Authentication15/25API key required
Pricing17/20Freemium tier available
Docs14/20Documentation URL provided
Formats9/15Single response format
Freshness20/20Verified within 6 months
Auth quickstart
- Sign up with the provider to get an API key.
- Send it on every request as a header
Authorization: <key> - The exact header isn't documented — Authorization is a common default; confirm in the provider's docs.
Stored keyNo key stored
Your key is stored only in this browser (localStorage) and sent directly to the API — never to greatapis.