I recently had the need to check a transaction on the blockchain in order to verify that the same transaction had been correctly stored.
The term explorer refers to a website, or an app, which allows anyone to access the transaction data recorded on the public Bitcoin blockchain.
In fact, despite being public, the Bitcoin blockchain is a very large file (about 350 GigaByte).
To make it easier to consult, special websites have been created that allow real navigation within it (for example to consult the blocks or individual transactions).
One of the best known and most used explorers is that of the former blockchain.info site, now blockchain.com.
It has recently been redesigned, particularly with regard to navigation within the data and off-chain charts.
It is still widely used, so much so that it is probably the most used Bitcoin explorer in the world (although the site has now become above all an exchange).
Another widely used explorer is blockchair.com, which in addition to the previous one has the ability to navigate within different blockchains. In fact, in addition to Bitcoin, it supports Ethereum, Ripple, Bitcoin Cash, Cardano, Bitcoin SV, Litecoin, EOS, Tezos, Stellar, Monero, Dash, Zcash, Dogecoin, Mixin, Groestlcoin.
This is by far one of the most complete and used explorers (even if it is much less visited than the previous one).
Another widely used explorer is that of blockcypher.com, which has the particularity of allowing navigation even on the Bitcoin testnet.
It also supports the Ethereum, Litecoin, Dogecoin, Dash blockchain.
However, it does not show off-chain data, as the previous two do, which remain, in general, among the most used (also for this reason).
In reality, the second most used Bitcoin blockchain explorer in the world would seem to be that of btc.com; but this site is not just an explorer. In fact, it is also the site of the homonymous mining pool, one of the most important in the world.
It also allows navigation within the Ethereum and Bitcoin Cash blockchain, but the off-chain data it offers are above all those related to mining.
Another well-known explorer is that of blockstream.info (perhaps the most essential and spartan of all).
It is known because it was made by the company of the same name that is working on the Liquid Network. In fact, its peculiarity is precisely that of allowing navigation also within the Liquid blockchain, in addition to that of the Bitcoin testnet, but its features are really limited (without off-chain data).
Since, as far as on-chain data is concerned, basically all explorers allow you to view the same data, the difference is the ease of use and the offer of off-chain data (and it is perhaps for this reason that despite everything blockchain.com remains the most used).
Thank you for taking the time to read this article.