Blockscout is the open-source, EVM-compatible block explorer behind dozens of public chain explorers (Ethereum mainnet, its L2s, and more), and its REST v2 API exposes the same block, address, token, and transaction data that powers those explorer UIs. No signup or API key is required for the per-instance hosted public REST API, though anonymous callers are rate-limited per endpoint (confirmed live: `x-ratelimit-limit` varies by route, e.g. 180 on an address lookup vs. 10 on `/stats`); docs.blockscout.com also flags this per-instance API for deprecation in favor of a separate, paid, API-key-gated multichain "PRO API," though the free per-instance API this entry tracks was still live and keyless as of this run's probe. Every response is JSON.
Blockscout is the open-source block explorer behind dozens of public chain explorers, and its REST v2 API exposes the same address, transaction, and stats data that powers the explorer UI. A live GET to eth.blockscout.com/api/v2/addresses/{address} in this run returned full real account data — balance, contract-verification status, resolved ENS name — with zero credentials, and access-control-allow-origin: * on every call. eth.blockscout.com is documented here as the Ethereum-mainnet instance; Blockscout also runs a separate hosted instance per chain (L2s, sidechains, and more) behind the same API shape.
AuthenticationNone requiredCall it straight away — no key, no signup.
HTTPSSupportedTraffic is encrypted in transit.
CORSEnabledCallable directly from browser JavaScript.
PricingFreeNo paid tier — free for the documented use case.
FormatsJSONResponses can be requested as JSON.
GreatAPIs Score
Score94out of 100
Authentication25/25No authentication required
Pricing20/20Free to use
Docs20/20Machine-readable spec file bundled
Formats9/15Single response format
Freshness20/20Verified within 6 months
Embed this badge
<a href="https://greatapis.com/api/blockscout/"><img src="https://greatapis.com/badge/blockscout.svg" alt="Scored 94 on greatapis.com"></a>
Auth quickstart
No API key or signup required for this per-instance public REST API — every probe in this run answered with no auth header sent at all. Anonymous callers are rate-limited per endpoint (see gotchas); a bypass-429-option: temporary_token response header points at a captcha-gated temporary token for higher throughput, and Blockscout also sells a separate, paid, multichain "PRO API" (dev.blockscout.com) with its own API keys and higher limits — not required for the reads this quickstart covers.
Stored keyNo key stored
Your key is stored only in this browser (localStorage) and sent directly to the API — never to greatapis.
Endpoints
CelestiaService3
GET/api/v1/celestia/blob
Parameters
Name
In
Required
Type
height
query
no
string
commitment
query
no
string
skipData
query
no
boolean
Responses
Status
Description
Schema
200
A successful response.
v1CelestiaBlob
default
An unexpected error response.
rpcStatus
GET/api/v1/celestia/l2BatchMetadata
Parameters
Name
In
Required
Type
height
query
no
string
namespace
query
no
string
commitment
query
no
string
Responses
Status
Description
Schema
200
A successful response.
v1CelestiaL2BatchMetadata
default
An unexpected error response.
rpcStatus
GET/healthIf the requested service is unknown, the call will fail with status
NOT_FOUND.
Parameters
Name
In
Required
Type
service
query
no
string
Responses
Status
Description
Schema
200
A successful response.
v1HealthCheckResponse
default
An unexpected error response.
rpcStatus
addresses15
GET/addressesget native coin holders list
Responses
Status
Description
Schema
200
token
—
400
bad input parameter
—
GET/addresses/{address_hash}get address info
Parameters
Name
In
Required
Type
address_hash
path
yes
string
Responses
Status
Description
Schema
200
address
Address
400
bad input parameter
—
GET/addresses/{address_hash}/blocks-validatedget blocks validated by address
Parameters
Name
In
Required
Type
address_hash
path
yes
string
Responses
Status
Description
Schema
200
address
—
400
bad input parameter
—
GET/addresses/{address_hash}/coin-balance-historyget address coin balance history
Parameters
Name
In
Required
Type
address_hash
path
yes
string
Responses
Status
Description
Schema
200
address
—
400
bad input parameter
—
GET/addresses/{address_hash}/coin-balance-history-by-dayget address coin balance history by day
The x-ratelimit-limit/x-ratelimit-remaining/x-ratelimit-reset response headers do not carry one fixed number for the whole API — a live probe in this run got x-ratelimit-limit: 180 on /addresses/{hash} but x-ratelimit-limit: 10 on /stats, confirming the limit is set per endpoint, not per instance. docs.blockscout.com's own requests-and-limits page separately documents a default "no API key (by IP)" limit of 3 requests/minute for the legacy per-instance model — that page's stated number and this run's observed headers don't agree, so no single rateLimit figure is trustworthy enough to state as fact; treat the headers on your own calls as the source of truth.
docs.blockscout.com carries an explicit notice that "PER INSTANCE API WILL BE DEPRECATED JULY 1" in favor of the paid, multichain PRO API (5 RPS on its free tier, API-key gated) — yet this run's live probe against eth.blockscout.com/api/v2/* still returned normal 200s with no key, so the per-instance API this quickstart documents is still live in practice even though its long-term future is explicitly in question.
A syntactically valid but unused address doesn't 404 — a live GET to a made-up-but-valid 40-hex-char address returned HTTP 200 with "coin_balance":null,"exchange_rate":"1880.27","is_contract":false and most other fields null, not an error. A genuinely malformed address (wrong length/characters) is what actually 404s/422s: a live GET to /addresses/not-a-real-address returned HTTP 422 {"errors":[{"title":"Invalid value",...,"detail":"Invalid format. Expected ~r/^0x([A-Fa-f0-9]{40})$/"}]}, and a made-up transaction hash in the correct format returned a plain HTTP 404 {"message":"Not found"}.
The entry's url (dev.blockscout.com) is Blockscout's PRO API developer portal, not the REST API reference — the actual endpoint docs live at docs.blockscout.com/devs/apis/rest, confirmed live 200 in this run and recorded as this entry's docsUrl.
Availability
Uptime100%
Median latency667 ms
Last checkUp · 200 · Sep 2026
16 checks since Aug 2026. A person runs this check by hand, not an automated monitor.
