Learn how to effectively use our block explorer.

Blockchain Simplified

Welcome to CoinMarketCap’s Block Explorer! If you’d like to become confident in using a block explorer and fully understand its functions, we’re here to guide you through the site. To start off, you can open up https://blockchain.coinmarketcap.com in your web browser and follow along using the guide for an optimal learning experience.

First off, what’s a block explorer? To provide some basic terms, a block explorer is a blockchain search engine that allows you to search for a particular piece of information on the blockchain. The activities carried out on crypto blockchains are known as transactions, which occur when cryptocurrencies are sent to and from wallet addresses. Each transaction is recorded onto a digital ledger, known as a blockchain. Blocks on the blockchain are collections of transactions that were processed and approved by a group of third-parties known as miners (for most Proof-of-Work cryptocurrencies).

To recap, a block explorer is an online tool to view all transactions that have taken place on the blockchain, the current network hash rate and transaction growth, and the activity on blockchain addresses, among other useful information. You can think of it as a window into the blockchain world, giving you the opportunity to observe what’s happening on it.

To assist users in using the block explorer, we have written this guide for those interested in the concept of blockchain, its terminology, and processes. Our block explorer visually displays block activity as it is confirmed in real-time, which allows users to take a more engaging approach to the data. They can look up a particular block number, and inspect it at a another level by viewing address and transaction details that make up a block.

CoinMarketCap’s block explorer currently has indices for Bitcoin, Ethereum and Litecoin, which forms the basis of learning how to navigate and comprehend the data for other blockchains. We will be adding more cryptocurrencies and functionalities to our block explorer, so users can explore real-time blockchain data and perform more in-depth analyses.

Who Uses A Block Explorer?

For one, traders and users, who often buy and sell crypto will utilize the block explorer to check on the status of their transactions. Once users initiate a transaction, they will receive an automatically-generated transaction hash and can use it to look up details of the payment and whether it was successful.

Miners use the block explorer to confirm significant block activity, especially to check if they have been successful in creating a particular block, which means they receive the block reward.

Crypto enthusiasts can track market activities such as the number of Bitcoins in the circulating supply, the market cap, or note the amount of energy required to mine Bitcoin. On the CMC block explorer, they can compare market data alongside of blockchain transactions, which can be seen as the underlying driver for market activity.

Have fun on your blockchain journey! Our aim for the block explorer is a no-frills, user-friendly tool that gives you easy access to data from multiple search points, and provides a more intuitive understanding of what you’re searching for. Let’s take a look at the block explorer!

Homepage

Upon landing on our site, you’ll be greeted by the homepage and a few elements. On the left side of the header, you’ll see the CoinMarketCap logo, which takes you back to the block explorer homepage any time.

The right-hand side includes a language option to view the block explorer in English or Simplified Chinese (with more languages coming soon). Next to it is a small search bar that prompts you to search for a component on the Bitcoin blockchain. This search bar is always present on the site in the same spot, and can be switched to a different blockchain, like Ethereum or Litecoin, by clicking on the icon:

Main Search Bar

The main search bar is where you can look up something specific right away. As a block explorer user, you can perform a search for the following items:
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1. Blocks: block height (block number)
2. Transactions: transaction hash/ID
3. Wallets: wallet address
4. Ethereum name service (ENS)

This search bar is set to search the Bitcoin blockchain by default, but you also can search the Ethereum or Litecoin blockchains by clicking on the small arrow and making your selection on the dropdown menu.

One common use case that you can try on the block explorer is checking on the status of a transaction. This can be done by copying and pasting the transaction ID into the search bar. Users can also confirm whether the cryptocurrency they are waiting on has arrived yet by pasting their wallet address into the search bar. (We always recommend the copy-and-paste method to prevent typing errors!).

The block explorer will display the address and its most recent transactions, as well as all transactions that have been carried out to and from that address. Within a block, there can be thousands of approved transactions, so we do not recommend searching for a specific transaction by scrolling through the pages (of course, unless you want to!). However, if you are interested in the exact order of a transaction in comparison to another (in the same block), you can utilize other indicators such as the transaction amount, and the payment’s timestamp to point you to the correct transactions.

Blockchain Overviews

As you continue scrolling down the homepage, you will see an overview of the Bitcoin, Ethereum, and Litecoin blocks. The current prices of one Bitcoin, Ethereum, and Litecoin are displayed in US dollars, along with their most recent market information. Keep in mind that these numbers are constantly changing as crypto is sold, bought, and mined. If some time has passed since you have entered the page, you can refresh it to view the most updated data. Of course, this data is powered by CoinMarketCap and is consistent with the numbers you will see on our site.

Market Data

Four market data factors are listed below each crypto to provide an overview of the value and size of that cryptocurrency. These help investors and analysts understand the coin’s current performance. Market cap, the total value of a cryptocurrency, is a term used by investors to measure the relative size of a cryptocurrency in relation to another. At CoinMarketCap, we calculate this by taking the current price of the cryptocurrency and multiply it with the circulating supply. Circulating supply takes into account the total number of coins or tokens that are being traded on exchanges and held in the hands of the public. Our reason for using circulating supply instead of maximum supply to calculate the market cap is because coins/tokens that are locked, reserved, or not able to be sold on the public market don’t affect the price and are not representative of the free market. Therefore, they should not be counted in the market capitalization. Here is an example of how market cap is calculated, using the Bitcoin market data from the image above:
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Price x Circulating Supply = Market Cap
$7,353.24 x 17,698,112 = $130,138,465,082.88  

‍$130,138,465,082.88 is the market cap of Bitcoin at the time of calculation.

‍Max supply is defined as the best approximation of the maximum number of coins from a specific cryptocurrency that can ever exist.

Cryptocurrencies take on different values at different times, but since there are fewer holders of crypto than the Euro or US dollar worldwide, crypto market caps experience more volatility when cryptoassets are bought or sold. Generally, the larger the market, the more stable it will become; however, regardless of how high a market capitalization reaches, no cryptocurrency is completely safe from external factors.By pinning the value of BTC and ETH (Ethereum) to USD, we can determine the value of a cryptocurrency relative to a more widely-known asset. Hash rate measures the computing power being consumed by the network to operate a particular blockchain. The hash rate of a computer may be measured in KH/s, MH/s, GH/s, TH/s, PH/s or EH/s, depending on the number of hashes produced per second. Using the image above as reference, Bitcoin’s 47.98 EH/s equates to 47.98 quintillion hashes, which is 4,798 followed by 16 zeros.

Recent Blocks

To the right of the blockchain and market data, the yellow and blue bars represent the most recent blocks, or recent groups of confirmed transactions that have been recorded on the Bitcoin and Ethereum blockchains. Blocks are chained to each other in the order they are created and always contain the unique hash number of the previous block.

This view of the blocks is constantly updated, with the earlier blocks appearing on the left to the most recently created block always located on the outer right-hand side. The blocks are sized proportionally to the number of transactions executed, so the taller they are, the more transactions have been completed during the period that the block was created. How tall or short a block looks depends on how many people are trying to transact in a certain period, and how many of those transactions have been validated. A transaction becomes more secure as new blocks are added onto the existing chain, since as it is more protected against network attacks and was proven to not have been double spent (see double spending).

If you hover your cursor over each block, its block number, along with the number of transactions confirmed within that block, will appear. Below the bars, the block height (or the block number) is the total number of blocks that have been created to date before the block in consideration. Once blocks are created, the records they contain are permanent and can’t be altered or deleted. This is what makes blockchain technology tamper-proof, as only new data can be added on the block. The total transactions (txs) is the number of all transactions ever approved in history for that particular blockchain. TPS (Transactions Per Second) gives you the average number of transactions completed over a 24-hour period. This number changes depending on the number of users sending cryptocurrencies.

View Blocks

To gain more information on a specific block, point your cursor over the three dots and click “View Block”. You’ll be taken to a list of recent Bitcoin blocks, where you can click on a block height to see the transactions contained in the block.

However, if you have already left the homepage, you can always search for any Bitcoin or Ethereum block by typing in the block number in the smaller search bar located on the top right-hand side of the page. Make sure you click on the correct icon to search within the correct blockchain.

Bitcoin Blocks

To view the Bitcoin blocks, click on “View Block”. Once you’re in the Bitcoin blocks page, you’ll see an overview of the Bitcoin blockchain, including the most recent market data and block details.

At the top, the blue coin icon refers to the type of asset that Bitcoin is defined as, while mineable means that this crypto is created by miners who solve cryptographic puzzles, and help verify transactions and add them to a digital ledger (which in this case, the ledger is the Bitcoin blockchain).

Most of the blockchain metrics on this page have been previously explained, except for two new terms: pending txs and difficulty. Pending txs are transactions that have been started but are yet to be confirmed by miners. This can occur for a variety of reasons, such as when the network experiences high traffic volumes, or when fees paid for that transaction were too low. Transaction fees act as an incentive for miners to process a transaction, so a lower fee can cause a delay in the speed that the transaction is added to the block. Difficulty refers to the measurement of how difficult it is to mine a block. In Bitcoin, the difficulty is adjusted periodically as a function of how much hashing power has been deployed by the network of miners. BTC dominance is introduced to the market data, which is defined by CoinMarketCap as an index that compares the market capitalization of Bitcoin with the overall market cap of all other cryptocurrencies in existence.

Beginning with the first column in the Block View section, “Block Height” lists the recently created blocks and the total amount transacted in each block represented in BTC and USD valued at the time the transaction was verified. This is followed by a unique block Hash ID, a cryptographic code generated to conceal data input and protect it from being altered. The “Transactions” column shows how many transactions have been successfully posted on that block, and the last column records the date and time it was completed (in YYYY-MM-DD format).

Should you want to view more details on a specific block, clicking on the block height will take you to all the transactions contained in that specific block.

As an example, we have clicked on block 575853 to gain more information. The first part shows the block header and its summary. In the “Transactions” subheader below, sometimes the sender or recipient may have an identifiable name (i.e. Coinbase, F2Pool) if the owner of the address has chosen to identify itself publicly. Otherwise, alphanumeric wallet addresses will be listed. The first transaction in a Bitcoin and Litecoin block is the block reward sent to the mining pool, or group of miners who combine their computational powers to collectively solve Proof-of-Work cryptographic puzzles. You will sometimes see “unable to decode” and “0 BTC” in transactions. This simply means that the transaction does not conform to a standard set script of transaction outputs. It is possible that the sender is using the blockchain as a way to store information and create a data record.

View Transactions

To take a closer view at the Bitcoin data, select the “Transactions” tab to see the individual transactions within their associated block. Transactions refer to the act of sending and receiving cryptocurrency. Each transaction ID (also known as Hash ID, TxHash, or TxID) is generated by a hashing algorithm according to the information contained in that particular transaction. This hash ID can be used as a digital proof of payment. Altering that info in any way causes the hash ID to change and alerts users that the data has been tampered with. Recipients of a crypto payment may also look up the transaction by its hash ID to see its status and confirm whether tokens or coins have arrived in their wallet.

Sending crypto requires a handling fee in the same way that it costs money to make a bank transfer. The key difference is crypto fees come at very minimal amounts compared to traditional bank fees. In the image above, a transaction sent $6,709.35 worth of BTC and the fee amounted to only $3.02. In fact, whether you send $6 million or $6, the fees will remain constant but rather are determined by transaction size. This is why some argue that cryptocurrencies are a much more efficient mode for transferring large sums of money. Moreover, the receiver of the Bitcoin does not incur an extra charge, even when the transfer is sent from another part of the world. Crypto transactions are generally processed within 24 hours, if not in the same hour or within several minutes.

Block Rewards

Block rewards are given to miners, who play a fundamental role in the blockchain ecosystem. Using mining hardware and software, miners compete with each other to be the first to solve cryptographic puzzles and produce Proof-of-Work. In this process, they also verify transactions to ensure that the BTC hasn’t been spent elsewhere. The miner who correctly solves the equation first receives the block reward, along with the transaction fees. Other miners must then validate the solution produced by the first miner so they reach a general consensus regarding the data on the blockchain.The block reward serves as an incentive for miners to continually verify the transactions and keep the blockchain updated and secure.

Transaction View

Clicking on any TxHash on the Block View page brings you to a dedicated page for that specific transaction. On this transaction page, you will be able to see whether the transaction has been successfully confirmed, marked in green. Block confirmations are the number of blocks that have been created after this block and are an indication of how secure the transaction is at the time you are viewing it. One confirmation simply means that the transaction has been successfully approved and added to the chain of blocks. Two confirmations indicate that a new block has been created and chained to the previous block with the transaction in it. The more confirmations that transaction has, the more secure it is.

As a general rule, a secure transaction requires 6 confirmations, which takes about an hour to create on the Bitcoin blockchain (one block is generated every ten minutes or so on the Bitcoin blockchain). The size of a Bitcoin transaction refers to how many bytes that transaction is. This depends on how many inputs and outputs are generated to complete the Bitcoin transaction, and the type of transaction it is considered to be. Standard transactions directly sent to a public key or address will be smaller than in size than a nonstandard, or more complex transaction. Bitcoin’s maximum block size is 1MB, but sometimes it can be bigger due to Segwit.

Bitcoin Transactions: UTXO's

In this Bitcoin transaction, you’ll notice two addresses that contain two different amounts under the “From” and “To” sections. A Bitcoin wallet does not only contain one balance, but rather is made of multiple, smaller balances known as unspent transaction output, or UTXO’s, which create a lump sum that makes up an overall balance. These individual UTXO’s remain intact until a transaction is initiated and then are randomly selected one by one until it meets or exceeds the transaction amount. At this moment, unspent transaction outputs are broken up so that the correct amount, including fees, are distributed while the remaining value of the Bitcoin is returned to the sender as change.

Address

Clicking on a Bitcoin address brings you to its own wallet information page, with a QR code option and the list of all transactions the specific address was involved in. You can also click on the address to copy it. The current wallet balance is listed, including the volume of Bitcoin that has been received and sent, the total number of transactions made, and how many were incoming tx (transactions) and outgoing tx (transactions). Exploring the address is similar to viewing a bank statement of all the purchases that have been made with that account.

Ethereum Gas, Gwei, and Nonce Explained

When it comes to Ethereum, smart contracts are involved. These digital agreements are distributed and stored across a decentralized, global network. Using the Ethereum Virtual Machine, any application or agreement can be written to self-execute when certain conditions are met.

In Ethereum, gas is known as the “fuel” of the Ethereum network, which is the same thing as a Bitcoin transaction fee. Gas is represented in gwei, which is equal to 0.000000001 Ethereum. Gas price refers to the cost you set and are willing to pay for the computational work required to process transactions. Prior to sending an Ethereum payment, you also indicate the max amount you want to spend on your transaction, which is listed as the gas limit. A standard ETH transaction costs 21,000 gas, and the more complex a transaction is, the more computing power is required to process it. Gas used shows how much fuel was actually used to process the transaction and fees show the amount of gas spent in USD and ETH, with unused amount being returned to the user. Each transaction contains a nonce, which is the number of all transactions sent by this address and is used to prevent double spending.

Litecoin

After its fork from Bitcoin, Litecoin P2SH (Pay To Script Hash) addresses have been changed from 3 to M, to avoid confusion between Bitcoin and Litecoin addresses. A P2SH allows a transaction to be redeemed and used according to the conditions of the recipient, rather by the requirements of the sender. Litecoin users should note that the change in P2SH formats are simply two different encodings for the same address.

More Market Data

Do you want to view more data? Our “View Market Data” option will take you directly to the CoinMarketCap website, where you can gain access to information on coins, tokens, and different exchanges.

In summary, CoinMarketCap’s block explorer provides four main perspectives of browsing different blockchains for its users. On the homepage, you begin with a current summary of the blockchain and then move to a list of blocks with the option to select and read the data on a single block. You also have access to a list of transactions and can view their details individually before finally proceeding to the single address page, which shows records of incoming and outgoing payments (among other data) the address was involved in. Miners, crypto traders, and blockchain learners use this tool to stay updated on the state of blockchain and their crypto payments. Our block explorer allows you to tailor your search results based on your data requirements, and our different entry points provide versatility on how you retrieve the information you need.