Multi-Testnet Balance Aggregator for Dev Wallets

WHAT IT DOES

Multi-Testnet Balance Aggregator for Dev Wallets is a developer-focused utility that aggregates native token balances for multiple wallet addresses across multiple EVM testnets simultaneously. It reads wallet addresses provided by the user, connects to public testnet RPC endpoints, and fetches native token balances for each address on each selected chain. The tool displays a comprehensive summary including total aggregated balance across all chains, per-wallet totals across all chains, and a detailed per-chain breakdown showing balances for each address on each testnet. It also displays the current block number for each chain to provide context for the balance data. By aggregating balances across testnets, developers can quickly assess their testnet token distribution across multiple wallets and chains without manually checking each one individually.

HOW TO USE

Connect your wallet (optional — the tool works without connection). Enter one or more wallet addresses into the text area, with one address per line. Optionally, specify which testnet chains to check by entering comma-separated chain names or IDs (e.g., "sepolia, goerli, mumbai, 5, 80001"). Leave the chain input empty to use the default testnet list: Sepolia, Goerli, Mumbai, BSC Testnet, Arbitrum Goerli, Optimism Goerli, and Avalanche Fuji. Click "Aggregate balances" to fetch balances from all specified testnets. The tool will display a summary showing the total aggregated balance across all chains, per-wallet totals, and a detailed breakdown for each chain with the balance for each address.

TECHNICAL NOTE: PARALLEL BALANCE FETCHING WITH RATE LIMIT HANDLING

The tool implements a multi-stage balance fetching strategy that sends parallel RPC requests to multiple testnet endpoints. It uses a pre-configured list of public RPC endpoints for each supported testnet and attempts to fetch balances for all addresses on each chain concurrently. The tool handles RPC rate limits by implementing a concurrency cap of 4-6 simultaneous requests per chain, with automatic backoff and retry logic for rate-limited responses. If a particular RPC endpoint fails, the tool continues to the next chain rather than failing the entire aggregation. Each balance request includes the current block number, providing context for the balance snapshot. The tool also aggregates native token balances only — ERC-20 token balances are not included in this version but can be added by providing token contract addresses.

WHAT IT CANNOT SEE

The tool cannot aggregate balances for non-EVM chains, including Bitcoin, Solana, Cosmos, Tron, or any non-EVM blockchain. It cannot retrieve balances for wallets that have not been funded on the specified testnets. It cannot detect testnet resets that have wiped balance history, meaning balances shown may be from after the most recent reset. The tool is limited by RPC provider rate limits and archival node availability; if a public RPC is overloaded or unavailable, balances may be missing. It cannot calculate fiat values or historical balance changes without external pricing data, which is not included. It cannot identify wallet ownership, aliases, or labels for addresses. The tool does not track transaction history or logs; it only displays current balances.

PLEASE NOTE

This tool is designed exclusively for EVM-compatible testnets (Sepolia, Goerli, Mumbai, BSC Testnet, Arbitrum Goerli, Optimism Goerli, Avalanche Fuji, etc.). It does not support mainnet or non-EVM blockchains. The tool uses public RPC endpoints which may have rate limits or availability issues. For accurate results, ensure the wallet addresses are correctly formatted (0x-prefixed). Testnet resets can wipe balances; always verify the latest reset information from official sources. The tool is read-only and does not modify any state. The tool provides no warranty of data accuracy; users are responsible for verifying balance information from multiple sources.