TLDR
- Starknet’s sequencer failure caused a 3-hour outage, affecting Ethereum L2 transactions.
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Starknet confirmed that transactions from 2:23 AM to 4:36 AM UTC were not processed.
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The network has resumed full operation, with most RPC providers back online.
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This marks Starknet’s second major outage in two months, raising concerns about reliability.
Starknet, an Ethereum Layer 2 blockchain, suffered a significant outage on September 2, 2025, leaving users unable to process transactions for nearly three hours. This marks the second major outage for the network within two months, raising concerns over its reliability. The issue was tied to the failure of the sequencer, the component responsible for ordering transactions on the network.
The outage began in the early hours of the day and was caused by the sequencer’s inability to recognize the “Cairo0” code, essential for processing transactions. The disruption left many users unable to complete transactions, and block creation times slowed considerably. Starknet’s team acted quickly to restore the network’s functionality and confirmed that the issue was fixed after several hours of downtime.
Outage Causes and Recovery Efforts
According to Starknet’s official update on social media, engineers identified the root cause of the outage and began deploying a fix immediately. The sequencer failure prevented transactions from being processed between 2:23 AM and 4:36 AM UTC. As a result, the network underwent a reorganization at block 1,960,612, which led to a loss of approximately one hour’s worth of activity.
Starknet’s recovery efforts have since brought the network back online and operational. The post on the official status page confirmed that block production had resumed and that most RPC providers were up and running. Further, Starknet assured the community that any affected transactions would need to be resubmitted by users, as they did not appear on-chain.
“The network is back online and fully operational. Most RPC providers are up-and-running, and remaining ones will upgrade shortly,” Starknet said in a statement. “All transactions from block 1,960,612 onward will need to be resubmitted.”
User Concerns Over Reliability of Starknet
The latest outage has subsequently raised questions about the reliability of Starknet as an Ethereum scaling solution. With $548 million in total value locked (TVL), Starknet is the seventh-largest Layer 2 network for Ethereum. However, this recent incident follows a smaller outage that occurred in July 2025, where the network experienced slow block creation times for just 13 minutes.
The repeated failures have led to concerns among some in the Ethereum and DeFi communities, questioning the robustness of the network’s infrastructure. While the Starknet team has committed to resolving these issues, the recurring outages highlight the challenges faced by Layer 2 solutions that aim to scale Ethereum’s capabilities.
Starknet is designed to improve Ethereum’s scalability through zero-knowledge rollups (ZK-rollups), which batch transactions off-chain and submit cryptographic proofs to the mainnet. While this mechanism reduces fees and increases throughput, it still relies on centralized components like the sequencer, which can become points of failure if not managed correctly.
