Blockchair API provides developers, researchers, and businesses with access to data contained in 16 blockchains. The API supports numerous analytical queries like filtering, sorting, and aggregating blockchain data with high uptime.
It doesn’t get any better than this:
Fetch the balance for up to 25,000 addresses under 1 sec
One endpoint for all blockchain data your product needs
Batch requests for transactions and addresses
Get the most important stats on all supported blockchains via one API request