This Tutorial Explains What is a Blockchain Explorer, why use them and how do Blockchain Explorers work, their History and some Common Blockchain Explorers:
Blockchain explorers are the Google of cryptocurrencies and blockchain. They allow users to access different details related to transactions on specific wallet addresses and blockchains including amount transacted, sources and destination of funds, and status of the transactions.
They can be used to extract virtually any data related to transactions, wallets, and blockchains including rich lists and hidden messages.
This tutorial explains blockchain explorers, their histories, use cases, and the main explorers available. We will discuss in detail the workings of a blockchain explorer, what it is comprised of and why it is needed.
What You Will Learn:
What Is A Blockchain Explorer?
The below image shows the blockchain explorer recent transactions:
A blockchain explorer is a piece of software that uses API and blockchain node to draw various data from a blockchain and then uses a database to arrange the searched data and to present the data to the user in a searchable format.
User’s inputs are searchable terms on the explorer which are then searched through an organized table on the database. The explorer will already have organized data from a blockchain into the table format.
For most users, a blockchain explorer will allow you to search and explore data about recently mined blocks or recently carried out transactions on a blockchain. Ideally, they allow you to view a live feed of blocks as they are mined, as well as the data related to the blocks.
However, they also allow you to do the following:
#1) Explore the transaction history of any wallet address: This allows us to audit any wallet address and improves transparency on a blockchain.
Latest transactions in a blockchain and amounts:
#2) Explore receiving addresses and change addresses: In addition to the transaction receiving address, you can see the change address, which is an output that returns crypto to the spender to prevent too much of the input value from going to the transaction fees. This also improves the transparency of transactions.
#3) Explore the largest transaction of the day: This is supported by some explorers.
#4) Explore Mempool status: This allows us to explore the unconfirmed transactions on a blockchain including their details.
#5) Explore double-spend incidents: Some explorers support the discovery of how many double-spend transactions are taking place in a blockchain.
#6) Explore orphaned and stale blocks: These are blocks that are not attached to the longest blockchain even after mining and their parent blockchain is unknown. Stale blocks are those whose parents are known but still aren’t attached to the longest known chain. Some explorers allow us to see how many of these blocks were realized in a blockchain.
Latest transactions in a blockchain and amounts:
#7) Explore the pool or person who found or mined a particular block: Different individuals and mining pools (groups that combine their computing resources to mine crypto) compete to mine blocks in any given blockchain and explorers allow us to find who successfully mined a given block defined by its height.
#8) Explore genesis blocks: You can find the block that was mined first on a given chain, by whom as well as its other data.
#9) Allows users to see fees of transactions, blockchain difficulty, hash rate, and other data.
Blockchain explorer showing fees and address:
Why Use Blockchain Explorer?
Blockchain explorer applications:
Blockchain wallets can provide different kinds of data, but the view is limited to the data related to the keys that the wallet manages. Explorers are used for viewing data related to transactions carried out on all wallets of a given blockchain.
- Transparency: They allow you to check balances and spending on smart contract addresses such as when users are participating in an Initial Coin Offering, ICO.
- Checking if a wallet address is valid to a blockchain before sending crypto to a person.
- Checking if a transaction has been sent to the person it is being sent to. It is like having some public evidence that you have sent through cryptocurrencies to the person. Owners can check their wallet balances.
- Explorers can help to explain what is wrong with transactions that have not yet gone through or been confirmed and the stages of confirmation.
- It can help a user to know the current cost of a transaction or gas and therefore help to plan gas spending for future transactions.
- Sometimes it can help know if a group is the one that mined a transaction and probably help in making decisions of whether to invest more computing resources for future mining activity.
- It can help user developers who are programming their wallet if they are working properly to send and receive and store cryptocurrencies.
- Explorers can be used alongside other software such as nodes to corroborate data and information, for instance, to confirm other tools whether they are working appropriately.
- Developers can also check what functions and features they need to include in their wallets or other software using these explorers.
- As research tools, explorers can help make important decisions related to personal, group, and company finances.
History Of Blockchain Explorers
The concept of blockchain explorers emerged simultaneously with blockchains. This kind of software emerged because it was difficult to interrogate blockchains, for instance, when a person says that they had sent you cryptocurrencies yet your wallet hadn’t received any as claimed.
This may be because the transaction was yet pending for confirmation or had been rejected altogether. Or let’s say if you had sent crypto to a person and then they deny receiving any.
Secondly, it was hard to interrogate blockchains given that data in them is formatted in a certain way. While the information is stored and structured in a certain way, logically, it is indexed and grouped. To be accessible and readable to the naked eye and by an ordinary user, some additional software was needful.
Only skilled programmers were able to access additional or extra information from blockchains relating to transactions. They could do so by using command-line interfaces. Plus some command-lines needed to be executed to make data readable.
The first blockchain explorer, which was meant for Bitcoin blockchain, emerged in November 2010 at almost the same time when bitcoin was coming online. It was made available first at theymos.ath.cx:64150/bbe. The first explorer for Bitcoin was the Bitcoin’s equivalent of TorStatustorstatus.blutmagie.de.
The explorer provided data about Bitcoin and afterward, was moved to blockexplorer.com where the real stats page for the blockchain was posted.
However, many of the real-time stats pages existed before Bitcoin block explorers. They were first made available at theymos.ath.cx:64150/q. Real-time stats pages getdifficulty and getblockcount were created in July 2010. Others including decimaltarget, probability, hashestowin, nextretarget, totalbc and bcperblock came on after that.
These tools were developed to respond to the hard-coding into the text of block and difficulty values on the old wiki, which made the information obsolete.
How Does A Blockchain Explorer Work?
Blockchain explorers work by using a database that holds all blockchain in a searchable format and tables. An explorer will, therefore, work with a node interface to first extract all the data in a given blockchain. Once it derives the data, it then stores it in easily searchable tables.
It will gather the latest transactions and blocks and arrange them according to the defined searchable categories – for instance, wallet addresses transaction IDs, rich lists, balances, etc
An explorer also provides an interface to the user to allow them to search for the information. In terms of the technology, an explorer may use a relational database, SQL database, and an API.
You may be already familiar with the fact that each blockchain comprises many distributed nodes. Each node that can directly read data on a blockchain, grabs details of the latest transaction and mined block and other data. This is then sent to the database, where the data is arranged in the form of searchable tables.
This makes the explorer fast to use. Most blockchains use 24 tables including block, address, transaction, etc. Each row has a unique ID or key, for instance, a unique identifier for addresses used on the blockchain. Others create a unique key.
The user interface server for explorer then creates a web page that allows it to interact with a user by way of the latter input of searchable terms. It also provides an API to interface with other computers. These are sent to the backend server in a server readable format and the back-end server then responds to the user interface server for the search terms.
The user interface and API then sends the web pages as HTML to the browser to allow the reading of responses by the user.
Relational database: A relational database allows the storage of data components in a table such that they are related to each other. This allows the simplification of the management of data. For instance, instead of having a large block table containing all details for each block, the block table entries can be linked to an entry in a header table.
Structured Query Language (SQL or Sequel): This is a protocol and format for giving a query or searching a database. For instance, the software can create a table in the database, insert new records on the table, search the term, create a new table of results, and then present the results on a web page to the person searching.
API or Application Programming Interface: This is the protocol that allows users to communicate with machines through software. They define the criteria, format, and interactions for sending and receiving responses by the software being used by the user.
Common Blockchain Explorers
Blockchair blockchain explorer allows searching transactions in 15 blockchains:
Since the development of the first blockchain explorer tool, Blockexplorer.com was by BitcoinTalk Forum owner who goes by the name Theymos. In November 2010, when it came online, several explorers have since been developed.
- Blockchain.com, now blockchain.org: It allows search of Bitcoin blockchains by blocks, transactions, and addresses.
- Blockchair: It allows search of information on Bitcoin, Ethereum, and Bitcoin Cash blockchains including searching of words, phrases, nodes, Mempool size, and mining difficulty. Using it, you can know if certain interests such as teams are encoded on the blockchain.
- Tokenview: This is the Chinese-based explorer launched in 2018 and allows search of data on multiple (over 20 popular) blockchains.
- Etherscan: This is probably the most popular Ethereum blockchain explorer. It allows search of transactions, addresses, smart contracts, wallet balances, etc.
Etherescan is a popular Ethereum blockchain explorer for those participating in ICO fundraisings for crypto projects:
- Bitcoin.com: It allows the search of data on Bitcoin and ETH blockchains.
Blockchain explorers were developed out of the need to view and read detailed data about transactions as well as ensure transparency of transactions and blockchain. While the first explorer for Bitcoin came online in November 2020, but the real-time stats pages existed earlier.
Explorers enable reading of blockchain transaction histories, wallet balances, and to confirm the status of a transaction if or not it is confirmed. We also saw that a blockchain explorer helps to identify the mining pools that mine given blocks, block height, orphaned blocks, genesis blocks.
We saw that an explorer uses the database, API, and SQL to perform its operations. It creates a user interface that allows users to input data to search blockchains, and then it uses an API and user side server to convert the inputs to machine-readable formats and present them to the backend server.
On the other side, the explorer will have pulled information from the blockchain and structured them in tables in databases for easier and quicker reading and searches.
The backend server accomplishes the searches on databases and presents the results back through the user-side server and the API (which converts them to user-readable formats even with HTML page) to the webpage being used by the user.
We also learned about some main blockchain explorers.
Also Read => Bitcoin Mining Tools