DEFINITION of Block Explorer
A block explorer is a program or website accessible through a compatible browser that allows a user to search and navigate the blocks of a blockchain, their contents, and their relevant details. Nearly all popular cryptocurrencies, like Bitcoin and other altcoins, have online block explorers which are used by blockchain participants.
BREAKING DOWN Block Explorer
Since activities and objects on the blockchain network involve complex formats for denoting nodes, addresses, transactions and block numbers, a block explorer displays the key information in a human-readable format. It displays the content in the form of a standard website, which includes clickable hyperlinks allowing easy navigation options to switch from monitoring one piece of data to another related one.
A block explorer displays a lot of information about the blockchain and the blocks in a tabular form. It includes a list of blocks in the reverse chronological order of their find time. Contents of the display table usually include the block height, mining time, block hash, number of transactions on that particular block, block output in crypto tokens, cryptocurrency fee, and the name of the miner/pool which mined it. For instance, the BitcoinChain.com Bitcoin Block Explorer shows the following:
Additionally, block explorers may also provide additional information and features which include links to the previous and next transactions that involve an input and output, a list of all transactions at a particular address, existing and historical balances at a particular address, a search feature that can be used to search for addresses, transaction or blocks, feature to track the transfer history of the virtual coins, feature to monitor for transaction confirmation (acceptance or rejection), and feature to monitor the network hash rate and other related statistics of the blockchain. A few block explorers may also provide charts based on the available information.
Advanced cryptocurrency users, like miners, use block explorers to keep track of a variety of things for their activities. The primary one is the instant display of the latest blocks in the blockchain. For instant, as soon as a new block is found on a blockchain by a miner, all the block explorers should immediately list it.
Observing the first transaction on a newly found block provides vital clues to the income earned by its miners and its distribution, thereby indicating the value of mining rewards available at the moment. All other transactions on the block are fund transfers, which have an associated fee. It indicates the cost of transacting in the cryptocurrency at that moment, which can be high at times. Lists of pools garnering the maximum number of blocks indicate the pool strength and capacity, which may help a miner make a decision about joining or leaving a pool.
Additionally, block explorers may also display unconfirmed transactions as well as orphan blocks, which are detached from the main blockchain.
Common bitcoin block explorers include those provided by Blockcypher, BitcoinChain, and blockchain.info. (For more, see What does a block chain record in a bitcoin exchange transaction?)