Subscan

BWeb3 Portal to the Substrate & EVM Ecosystems

Subscan: The Polkadot Multi-Chain Explorer & API, Explained (2025)

This expert guide breaks down how to use Subscan for day-to-day Polkadot research and operations—accounts, extrinsics, staking rewards, OpenGov, and cross-chain (XCM) activity—plus how it compares to alternatives and how to integrate its API in your tooling.

What is Subscan (and why it matters)

Subscan is a one-stop, multi-chain block explorer for the Substrate ecosystem (Polkadot, Kusama, Asset Hub, and parachains) with growing EVM support. It positions itself as “Explorer as a Service” (EaaS), meaning the same productized explorer runs across many networks with consistent UX and endpoints.

On Polkadot specifically, Subscan exposes chain state in a familiar way—blocks, extrinsics, events, accounts—and adds governance, staking, XCM and portfolio-style views you’ll use daily as a builder, validator, or analyst.

For teams and integrators, Subscan offers a hosted API that serves indexed data for dozens of networks across the Substrate family.

ELI5: Subscan in one minute

Think of Subscan like search + analytics for Polkadot. You paste an address, hash, or block number; Subscan looks it up on the right chain and shows what happened (transfers, staking payouts, governance votes, XCM hops), with links you can drill into. It’s the fastest “what happened?” tool for most operational questions.

Key features for Polkadot users

1) Multi-network coverage

Dedicated explorers for Polkadot, Kusama, Asset Hub, and most major parachains—consistent navigation across all.

2) XCM dashboards

XCM Dashboard pages visualize asset flows, messages, channels, and transfers—ideal for debugging cross-chain UX or analyzing liquidity routes. Mobile-friendly improvements landed in 2025.

3) OpenGov (Referenda v2) views

Referenda pages show track, status, origins, amounts (with USD equivalents), and detailed posts—useful to monitor treasury and protocol changes across tracks.

4) Staking & rewards

Account pages tabulate rewards & slash history; portfolio tools add Stake Now / Claim Rewards shortcuts to reduce click-paths from research to action.

5) EVM-aware explorer

For EVM parachains (e.g., Moonbeam, Astar, peaq), Subscan renders EVM tx input data, ERC-20 balances with price, and ERC-1155 quantities.

6) Portfolio, watchlists & alerts

Subscan’s portfolio surface supports multi-chain tracking, yield monitoring, and quick actions; public pages highlight watchlists and real-time alerts.

How Subscan works (high level)

At a high level Subscan runs indexers that follow each chain’s blocks, parsing extrinsics/events (and EVM data where present). That data powers both the web explorer and dedicated HTTP APIs. There’s also Subscan Essentials, an open-source scaffold for Substrate explorers that underpins subscan.io deployments—handy to study architecture or self-host a minimal explorer.

Subscan complements developer-centric tools listed in the official Polkadot docs (e.g., Blockscout/Routescan for EVM/PolkaVM contexts) and sits alongside other Substrate explorers in the broader tooling landscape.

Subscan vs. other explorers (comparison)

Below is a pragmatic “choose-by-job” snapshot. (Features vary by chain; always check the live instance.)

Explorer	Multi-chain coverage	XCM visualizations	OpenGov (v2) views	EVM/PolkaVM features	Public API	Open source	Notes
Subscan	Extensive Substrate + many parachains	Yes (XCM dashboards: flows, messages, transfers)	Yes (referenda v2 details)	Yes (EVM input decode, ERC-20 price, ERC-1155 qty)	Yes (hosted API)	Essentials scaffold OSS	Portfolio, watchlists, quick staking actions.
Statescan	Polkadot, Kusama & parachains	Basic to moderate	Some	Limited EVM specifics	Not primary focus	Yes (open-source)	Positions itself as open-source, cost-effective.
Polkaholic	High parachain coverage	Strong (XCM monitoring)	Some governance linkages	Substrate-first	Public endpoints vary	Parts open	Focus on cross-chain account & XCM analytics.
Polkadot.js Apps (Explorer)	Any connected Substrate chain	No XCM visuals	Minimal governance UI	N/A	N/A	Yes	Best for dev-grade RPC interactions; Subscan offers friendlier read-only UX.
Blockscout / Routescan	Chain-by-chain	No	No	Yes (EVM/PolkaVM focus)	Yes	Yes (Blockscout)	Recommended for smart-contract traces on EVM/PolkaVM.

Ecosystem note: Subscan’s business model and funding have been debated publicly in the Polkadot forum; treat it as background when choosing infra partners.

Mini-guide: Trace an XCM transfer & verify a payout

A) Trace an XCM transfer (Polkadot → a parachain)

Open the XCM Dashboard on the source network (e.g., polkadot.subscan.io/xcm_dashboard).
Use “XCM Transfer” or “XCM Message” views to filter by Source and Target parachain.
Click a transfer row to drill into the message details, HRMP channel, and linked extrinsics/events on both sides.
Follow the links to account/extrinsic pages for confirmations, fees, and any failures (version mismatches, insufficient weight).

Why this matters: XCM debugging often requires seeing both ends of a hop. Subscan stitches these links and surfaces hot channels and recent flows to spot congested routes. Mobile optimizations in 2025 make quick checks easier on the go.

B) Verify a staking payout hit your address

Paste your address into Subscan (Polkadot instance).
On the account page, open the “Reward” tab for a dated list of payouts and slashes.
Click through to the payout extrinsic (or era payout) to confirm the block, validator, and amount (plus any fees).
If you use the Portfolio surface, the Stake Now / Claim Rewards buttons can jump-start common actions once you’ve verified data.

API notes (developers)

Scope & coverage. Subscan’s hosted HTTP API exposes indexed data for many Substrate networks (chain-agnostic endpoints like block, extrinsic, account, plus network-specific).
Example. Historical docs show POST /api/open/block with parameters (block_num, block_hash)—the exact pathing can vary by network and plan; consult the live docs your key unlocks.
Plans. The pro site lists coverage and pricing for HTTP endpoints by network; quotas are globally shared per key with typical RPS limits.
Self-host option. The Subscan Essentials repo provides the architecture baseline and plugin model if you need to study or replicate components.

Practical integration tips

Cache by block hash (immutable) rather than height when possible.
Treat Subscan as indexer truth for UX, but always retain a node RPC fallback for mission-critical paths.
For cross-chain analytics, correlate Subscan XCM ids with your own event tracking to avoid double-counting retries.

Common pitfalls & pro tips

SS58 formats: The same keypair can display different SS58-encoded addresses on different networks. Always copy addresses from the correct network explorer before transferring.
Finality lag vs. indexer lag: A block can be finalized while an indexer is still ingesting—refresh or check the peer network’s page if something looks missing.
Era math: On Polkadot, rewards are paid per era; filters make more sense by era than by date for reconciliation.
XCM versions: Many failures are due to XCM version/weight mismatches; use dashboards and extrinsic detail to see the error site quickly (source vs. destination).
EVM vs. Substrate roles: Some parachains keep native Substrate accounts alongside EVM addresses; use the EVM account lists and decoded input data when analyzing contract flows.

FAQs

1) Is Subscan the “official” Polkadot explorer? No single explorer is “the” official one. The Polkadot docs list multiple explorers (Subscan, Blockscout, Routescan, etc.), each serving different needs.

2) Can I rely on Subscan data for accounting? For ops dashboards and investigations—yes. For final accounting, always reconcile with node RPC or wallet exports to guard against transient indexer gaps.

3) Where do I see XCM activity? Use Subscan’s XCM Dashboard per network to view flows, messages, channels, and transfers, and drill into edges that failed.

4) How do I check if a treasury proposal passed? Open the Referenda v2 page, filter by track (e.g., Treasury), and inspect the decision status and execution details.

5) Does Subscan support EVM tokens and prices? Yes—Subscan’s 2025 updates added ERC-20 price display and improved EVM input decoding, plus ERC-1155 quantity views.

6) Can I get alerts when specific accounts move funds? Subscan provides watchlists and real-time alerts via its portfolio/pro surfaces.

7) I need a fully open-source explorer—alternatives? Consider Statescan (open-source, cost-focused) or community projects like Polkaholic for multi-chain analytics.

8) Is there any controversy around Subscan’s model? Funding and pricing have been debated on the Polkadot forum; review that context as background when choosing infra.

Conclusion

For builders and analysts, Subscan remains the quickest way to answer “what happened on-chain?” across Polkadot and its parachains—with strong XCM, OpenGov, and EVM surfacing, plus an API for your dashboards. Pair it with Polkadot.js Apps for dev-grade operations and alternative explorers for redundancy.

Subscan Community Videos

Subscan：Explore what is happening in the Substrate ecosystem - Decoded 2022