What‌ ‌is‌ ‌a‌ ‌Block‌ ‌Explorer?‌ ‌

5 min readNov 15, 2021


A block explorer is like a search engine for the blockchain: you can use it to browse the database of transactions in the same way that you use Google to find some information on the Internet. Block explorer allows you to find data on the latest blocks and transactions of any cryptocurrency, see wallet balances, sources and destination of funds, and much more.

Blockchain explorer helps everyone who needs to keep track of the current state of the blockchain or particular transactions: traders, miners, wallets, exchange services, and decentralized applications. Let’s see what a block explorer is, how it works, and how you can leverage it on advantageous terms with NOWNodes.

Blockchain Explorers: What Are They?

Every blockchain is a database that stores the whole list of wallet addresses and transactions that have ever been made in this blockchain. This database is open and available to everyone — you don’t need permission to see the balance of any wallet or the status of any transaction. Basically, a blockchain is one large file with information, but this information is not presented there in a human-readable way.

Here comes the question: what is a block explorer and what does it serve for? Block explorer solves the problem with readability: it helps users easily extract information from the blockchain. Popular block explorers include Blockchain.com for Bitcoin and Etherscan for Ethereum. Most blockchains have their own block explorers: here are two for Cardano and Solana.

Here’s a part of the Bitcoin blockchain explorer interface:

Block explorers of this kind may even display data that is not written in the blockchain itself. For instance, it’s the size of the mempool (memory pool) — a pack of transactions waiting to be confirmed and added to the blockchain. The size of the mempool reflects the level of market activity and network congestion, which is an important parameter for traders, miners, and all sorts of crypto projects.

How Do Blockchain Explorers Work?

As mentioned above, blockchain is a file containing information about the history of all transactions made in this network. But for a proper block explorer’s functioning, simply downloading a full copy of a blockchain is not enough — it needs to refresh it 24/7 to keep users updated on the info from the latest blocks. For this, block explorers leverage a full node — a participant of the decentralized cryptocurrency network that validates transactions, thus having access to the relevant information about them.

A full node downloads the whole copy of the blockchain (over 350 GB) and constantly updates it. A blockchain explorer is software that browses this database, collects information, and displays it in a user-friendly way.

How to Use Blockchain Explorers

Block explorers can be used in 2 main ways. The first one is manual — you enter an explorer blockchain website such as Blockchain.com or Etherscan and look for the information you need, be it the latest blocks or transactions, mempool size, etc. You can also use a search bar: enter a wallet address to see its balance and history, a transaction hash to see if the payment has been approved, or a block height to see what transactions were in that block.

However, this way doesn’t work for crypto projects: they need fresh information from the blockchain on dozens of parameters each second. For this, there are Blockchain-as-a-Service solutions — platforms that offer access to block explorers via API to anyone who wants to launch their crypto project, dApp, or a wallet.

Using such platforms is easy: you get an API key and then make requests to the node directly, which allows you to obtain the necessary information instantly in a form that will be convenient for your wallet or app to read.

NOWNodes — a Blockchain Explorer Provider

NOWNodes is a service that offers fast access to 40+ full nodes and explorers via API, including Bitcoin, Ethereum, Polkadot, and many others. We maintain full nodes of these cryptocurrencies, which allows us to draw information from them at any time.

Here’s what a block explorer experience with NOWNodes is like:

  • It’s fast. Our API gives you the response to any of your requests in less than 1 second.
  • It’s reliable. The API uptime rate is 99.95%, meaning that the service downtime is not more than a few minutes per month.
  • A big library of sample requests. In our Docs, see the Blockbook API folder to find a list of requests that you can make to a block explorer. Simply add your API key to the query URL, and you’re ready to execute the request.
  • Flexible pricing. Make up to 20,000 requests a day for free. Whenever you need more, see our Pricing section or simply reach out to us, and we will help choose the best plan for you.
  • Helpful support. Use the chat button on the main page or contact us for assistance — we will get back to help you with any issue ASAP.
  • Easy to start. It takes 3 easy steps to start working with NOWNodes, and it’s absolutely free. To find out how, see the quick guide below.

Feel free to earn more on our Service Quality Standard here.

How do I use a block explorer with NOWNodes?

Follow 3 simple steps and start making requests to a block explorer in mere minutes:

  1. Get a free API key. Head on to NOWNodes main page, leave your email, and get the letter with the key in a few seconds.
  2. Open our Docs and find the request you need. Here’s what a regular one looks like:

3. Paste your API key into the end of the query URL like this:


Now, you are ready to make your request and enjoy the service by NOWNodes!


A block explorer is a tool that allows you to find the necessary information in the blockchain — wallet balance, transaction status, and more. If you only need to quickly check something, you can use a block explorer like Blockchain.com, but if you run a crypto project, you’d need to access the explorer via API. You can do this with NOWNodes — we offer a fast and stable connection, and the setup process is very easy. For more details on using block explorers of specific coins, take a look at our latest articles on explorers for Dash, Digibyte, and Cardano.