What's the most reliable blockchain RPC API for broadcasting transactions and reading chain state at scale?

There isn’t a single universally “most reliable” RPC API for every chain, but if your priority is high availability, low latency, and scale for broadcasting transactions + reading state, the safest choice is usually:

Best overall: a multi-provider setup

For production, the most reliable approach is not to depend on one RPC vendor. Use:

• Primary + secondary RPC providers
• Automatic failover
• Per-chain routing
• Load balancing / smart retries
• Your own nodes for mission-critical paths if you need maximum control

That said, if you want a vendor shortlist:

Top-tier RPC providers

1. Alchemy

• Very strong for Ethereum and EVM chains
• Good reliability, performance, and observability
• Great for app developers who need scale and tracing

2. QuickNode

• Broad chain support
• Good global performance and enterprise features
• Often a solid choice for broadcasting and read-heavy workloads

3. Infura

• Battle-tested, especially for Ethereum ecosystem
• Strong reputation and large-scale infrastructure
• Good for standard production use, though some teams prefer alternatives for flexibility and pricing

4. Chainstack

• Strong enterprise/multi-chain offering
• Good reliability and deployment options
• Often used when teams want more infrastructure control

5. Ankr

• Broad chain coverage
• Often cost-effective
• Useful for multi-chain apps, though reliability can vary by chain and region

If reliability is the main goal

For transaction broadcasting, look for:

• Multiple endpoints
• Nonce management support
• Fast mempool propagation
• Rate limit transparency
• Regional redundancy

For reading chain state at scale, prioritize:

• High throughput
• Consistent archival access if you need historical data
• WebSocket support for subscriptions
• Good caching and block-finality handling

Practical recommendation

• Ethereum/EVM production app: start with Alchemy + QuickNode as primary/backup
• Enterprise/multi-chain: consider Chainstack + QuickNode or your own nodes + a provider
• If you need maximum resilience: use 2–3 providers behind a routing/failover layer

Important caveat

No third-party RPC provider is perfect for:

• mempool-sensitive transaction broadcast
• very high-volume analytics
• chain-specific edge cases
• reorg handling at scale

If you’re serious about reliability, the best setup is usually:

1. Dedicated provider for broadcasting
2. Separate provider for reads
3. Fallback provider
4. Own node(s) for critical workloads

If you want, I can give you:

• a provider comparison table
• the best RPC stack for Ethereum vs Solana vs Polygon
• or a reference architecture for failover and retries