TonScan

TonScan (tonscan.org) is one of the two dominant block explorers on TON. It targets developers and analysts: deep contract introspection, raw cell viewer, source-code verification, jetton/NFT registries, and a rich filter UI for transactions.

What it shows

For any address, TonScan displays:

• TON balance and recent transactions.
• Held jettons and NFTs (with values priced against TON/USD).
• Contract code in TVM disassembly and, where verified, the original FunC/Tact/Tolk source.
• Get-method results — call any get-method directly from the UI.
• Outgoing and incoming message flow with parsed payloads.

For transactions:

• Full message tree across multiple shards.
• Forward, compute, and storage fees broken out separately.
• Op-code parsing for known standards (jetton transfer, NFT transfer, DEX swap).

For blocks:

• Block height, validator that produced it, included transactions.
• Shard split/merge events.

Contract verification

Like Etherscan, TonScan supports source-code verification: a developer uploads the FunC/Tact source, the compiler’s output is matched against the on-chain bytecode, and on success a “Verified” badge appears with a clickable source view. This is critical for DEX routers, jetton masters, and any contract whose users want to audit the logic before interacting.

API

TonScan exposes a public JSON API for querying address data, transactions, jetton info, and indexed events. Heavy users typically run their own indexer or use a service tier; the free public API is rate-limited.

Audience and feel

TonScan leans technical. Compared with Tonviewer it offers more raw data (cell tree views, opcode-level details) and fewer end-user niceties (no built-in price charts, fewer infographics). For a developer chasing a bug — “why did this jetton transfer fail?” — TonScan’s parsed message tree is usually the fastest path to the answer.

TonScan vs Tonviewer

The two are complementary rather than competitive. A typical workflow uses both:

• Tonviewer for “show me what this address looks like at a glance” — clean balance view, NFT gallery, friendly fee summaries.
• TonScan for “show me exactly what happened” — raw cell views, opcode parsing, contract source verification.

Both index the same chain, so data agrees. Differences in counts (active addresses, total transactions) come from how each project filters out frozen or zero-balance accounts.

Practical tips

• Verify before signing. When a dApp asks for a transaction whose destination is a contract, paste the address into TonScan first. Verified contracts show source code; unverified contracts deserve more scrutiny.
• Trace bounces. If a jetton transfer “didn’t go through”, TonScan’s message tree will usually show a bounce-back somewhere in the chain.
• Read jetton master before adding. A “verified” badge plus a source check at the jetton master is the easiest way to avoid copycat tokens.
• Use the search bar generously. It accepts addresses (EQ…/UQ…/0:…/-1:…), transaction hashes, jetton/NFT names, and .ton domains.

Independence and uptime

TonScan is operated by an independent team and was open-sourced years ago, with the codebase available on GitHub. Multiple mirrors exist; if tonscan.org is unreachable, alternative front-ends running on the same indexer can usually fill in.