How to accelerate transactions broadcasting to L2 EVM-chain

On L2 EVM chains like Optimism, your transaction goes through a few stages:

Submission → Mempool → Sequencer inclusion → Block proposal → Block publishing.

Unlike Ethereum L1 where miners pick transactions from a global mempool, most optimistic rollups use a centralized sequencer, which decides the order of transactions.

Even if your raw transaction is valid and you send it right before the next block timestamp, it depends on:

When the sequencer receives your tx (network latency).

When it decides to include it (sequencers sometimes bundle or reorder txs to optimize throughput or fees).

The internal batching/cadence of the sequencer producing blocks.

That’s why your transaction shows up 2 seconds later (e.g., your tx sent at ts=1751080074, but ends up in block at ts=1751080077 even though a block at ts=1751080075 existed) — the sequencer either didn’t pick it up fast enough or decided to include it in the subsequent block.

1. Use a direct connection / RPC endpoint close to the sequencer

Hosting your infrastructure (wallet, relayer) geographically close to the sequencer reduces latency.

Public RPC endpoints can have additional lag; using private endpoints (e.g., Alchemy, Infura’s paid plans, or native endpoints by the L2 team) can give you lower latency.

2. Submit transactions with a competitive gas price

Even though Optimism and other rollups use fixed or low-fee models, some have fee markets (especially after upgrades). If there’s congestion, a higher fee can prioritize your tx.

3. Batchless / fast-mode APIs

Some sequencers provide priority transaction channels or low-latency APIs (these are usually enterprise features but worth asking if you send many txs).

4. Avoid congested times

L2s can experience spikes (like after airdrops or major events) causing delays in sequencer inclusion. Monitoring mempool congestion metrics (e.g., via block explorers or analytics) can help time your submissions.

5. Retry on dropped transactions

In case of dropped or stuck txs, consider resending with a higher gas price (aka replacement tx). Though not common on L2, some situations (like sequencer restarts) can cause mempool drops.

6. Check your node’s clock & nonce

If your local system clock is off or your transaction nonce is misaligned, it can cause unexpected delays or rejections that look like inclusion delays.

To accelerate transaction uploads to an L2 EVM-chain, I increase the gas fee, use a reliable RPC provider, or batch transactions efficiently. Some rollups offer priority queues for faster inclusion. Choosing less congested times and optimizing contract logic also help reduce delays during the L1-to-L2 bridging or transaction process.