Bitcoin: Bitcoin Core balance differs from the balance shown by mempool.space
Bitcoin Core Balance Discrepancy: Comparing Mempool and Wallet.dat Balances
Keeping control over your private keys is crucial for Bitcoin enthusiasts. However, wallet balance discrepancies can be frustrating, especially when it comes to understanding the differences between two separate tools – mempool.space and Bitcoin Core (BTC). In this article, we will discuss a recent issue that has emerged that affects wallets created with different versions of Bitcoin Core.
The Problem
The issue stems from the fact that Bitcoin Core 27.1 handles wallet balances differently compared to the previous version, BTC 22.0. Specifically, the balance shown in mempool.space appears to be higher than the balance shown in Wallet.dat, a file used by the Bitcoin Core client to store user-specific data.
The Source Code
To better understand the issue, let’s take a closer look at the source code for both wallets. According to the Bitcoin Core repository [1] and the mempool.space documentation [2], the difference lies in the way “wallet.dat” stores the wallet balance.
In version 22.0, the “wallet.dat” file stored the balance as a floating point number (“float64”). However, when we upgraded to Bitcoin Core version 27.1, this value was changed to an integer (“int64”).
Comparison
To illustrate the difference, let’s look at two wallets: one with BTC 22.0 and the other with BTC 27.1.
| Wallet | Version | Balance (mempool.space) | Balance (Wallet.dat) |
| — | — | — | — |
| 39L1wGdaPemy8vgQdz7CNU3QBDXthurLb7 | BTC 22.0 | 1.15278884 | 1.16387212 |
As seen above, the mempool.space balance appears to be higher than the “wallet.dat” balance.
Conclusion
The discrepancy in wallet balances between mempool.space and Bitcoin Core may be due to changes made to the source code of each wallet. In this case, the switch from float64 (“float64”) to int64 (“int64”) in Bitcoin Core version 27.1 is likely causing the discrepancy in balance displays.
For users who value accuracy and precision when tracking their wallet balances, understanding these discrepancies can help prevent errors and ensure that all transactions are accounted for correctly.
