Base Status - Incident History

Mainnet: Base Azul Upgrade - May 28th

Thu, 28 May 2026 18:00:00 +0000

THIS IS A SCHEDULED EVENT May 28, 18:00 - 20:00 UTC

May 22, 16:24 UTC
Scheduled - On Thursday, May 28th at 18:00 UTC (Unix timestamp 1779991200), Base Mainnet will undergo the Azul upgrade.

Operators of Base Mainnet nodes must upgrade to the 0.9.0, or greater, release of the github.com/base/base software. Preconfigured builds for this version are available from github.com/base/node with a corresponding release: https://github.com/base/node/releases/tag/v0.16.0.

NOTE
It is mandatory that nodes run base-consensus and base-reth-node binaries. Op-geth and op-node clients are no longer supported. This upgrade will also invalidate pending withdrawals. As seen in previous upgrades, users will need to submit a second proof transaction post-upgrade to complete withdrawals if they are still pending.

Please see the following document for migration instructions: https://docs.base.org/base-chain/node-operators/base-v1-upgrade.

Delayed Transactions

Thu, 14 May 2026 05:04:08 +0000

May 14, 05:04 UTC
Resolved - This incident has been resolved.

May 13, 16:44 UTC
Investigating - Base is experiencing an elevated rate of missed blocks. Transactions sent during missed blocks are delayed until the next successful block.

Elevated latency on Sepolia RPC

Wed, 13 May 2026 16:52:41 +0000

May 13, 16:52 UTC
Resolved - This incident has been resolved.

May 10, 19:03 UTC
Monitoring - We have temporarily decreased rate limits for this endpoint to ease traffic. Latency is moving back to normal on this endpoint.

May 10, 18:31 UTC
Identified - Latency on https://sepolia.base.org is high due to a node provider upgrade.

Node Peering Stability on Base Testnet and Mainnet

Thu, 30 Apr 2026 21:14:19 +0000

Apr 30, 21:14 UTC
Monitoring - There is no outage. This is preemptive in case node operators encounter peering issues.

However, upcoming p2p changes may impact peer discovery for Base nodes. If your node encounters p2p issues, please use the script linked here:

https://gist.github.com/meyer9/8f15028681045062d59b7521deb19822#file-add-peers-sh

Mainnet RPC Upgrade

Tue, 21 Apr 2026 17:36:02 +0000

Apr 21, 17:36 UTC
Completed - The scheduled maintenance has been completed.

Apr 21, 17:27 UTC
Verifying - Verification is currently underway for the maintenance items.

Apr 21, 17:00 UTC
In progress - Scheduled maintenance is currently in progress. We will provide updates as necessary.

Apr 16, 15:10 UTC
Scheduled - We will be upgrading the mainnet RPC endpoints (https://mainnet.base.org) to point at a different set of nodes. There should be minimal disruption, however you may notice some requests are cancelled for a short period of time.

Sepolia Testnet: Base Upgrade v1 - April 20th

Mon, 20 Apr 2026 18:00:07 +0000

Apr 20, 18:00 UTC
Completed - The scheduled maintenance has been completed.

Apr 20, 16:00 UTC
In progress - Scheduled maintenance is currently in progress. We will provide updates as necessary.

Apr 8, 18:49 UTC
Scheduled - On Monday April 20th between 16:00 and 18:00 UTC, the Base Sepolia Testnet will undergo the v1 upgrade.

Operators of Base Sepolia Testnet nodes must upgrade to the 0.7.0, or greater, release of the github.com/base/base software. Preconfigured builds for this version are available from github.com/base/node with a corresponding release: https://github.com/base/node/releases/tag/v0.15.0.

NOTE
It is mandatory that nodes run base-consensus and base-reth-node binaries. Op-geth and op-node clients are no longer supported.

Please see the following document for migration instructions: https://docs.base.org/base-chain/node-operators/base-v1-upgrade

Sepolia Testnet Unsafe Head Stalled

Thu, 16 Apr 2026 19:15:27 +0000

Apr 16, 19:15 UTC
Resolved - Block production has resumed on Sepolia testnet.

Apr 16, 18:26 UTC
Investigating - Base Sepolia Testnet is experiencing an outage in block production. The team is actively investigating.

Sepolia safe head delayed

Sat, 11 Apr 2026 00:45:01 +0000

Apr 11, 00:45 UTC
Resolved - This is now mitigated. Safe head is progress normally for Sepolia Testnet

Apr 10, 22:54 UTC
Investigating - We are currently investigating this issue. The Sepolia safe head is current stalled. This seems to affect op-node users running with consensus-layer sync mode.

Sepolia Testnet: Flashblocks down

Tue, 07 Apr 2026 00:55:34 +0000

Apr 7, 00:55 UTC
Resolved - This incident has been resolved.

Apr 7, 00:37 UTC
Identified - Flashblocks is currently down for Sepolia Testnet. The team has identified the issue and is rolling out a fix.

Base Mainnet Flashblocks Degraded

Wed, 01 Apr 2026 13:41:40 +0000

Apr 1, 13:41 UTC
Resolved - This incident has been resolved.

Mar 24, 15:16 UTC
Monitoring - A fix has been implemented and we are monitoring the results.

Mar 24, 13:55 UTC
Identified - We've identified an issue in our public RPC nodes that caused certain endpoints to not reflect latest flashblock data. Users may have also experienced increased error rates for read endpoints on https://mainnet.base.org/. We're working on implementing a fix.

Mar 24, 12:00 UTC
Investigating - Base Mainnet is currently not producing flashblocks. Normal block production is unaffected. We're actively working to restore flashblock production.

Base Mainnet Gas Limit Increase from 187.5Mgas/s to 200Mgas/s

Wed, 25 Mar 2026 21:00:07 +0000

Mar 25, 21:00 UTC
Completed - The scheduled maintenance has been completed.

Mar 25, 17:00 UTC
In progress - Scheduled maintenance is currently in progress. We will provide updates as necessary.

Mar 24, 21:28 UTC
Scheduled - Base Mainnet gasLimit will increase from 187.5Mgas/s to 200Mgas/s on Wednesday March 25th.

This will be achieved by the following parameter changes:
- Increasing gasLimit to 400_000_000 (this is a per block parameter)
- Decreasing the 1559 elasticity multiplier from 6 to 5
- Decreasing the 1559 denominator from 125 to 100

*NOTE*: This will result in a higher gasTarget, from 62_500_000 to 80_000_000 per block.

Transaction Inclusion Delays

Tue, 24 Mar 2026 13:13:59 +0000

Mar 24, 13:13 UTC
Resolved - Stability of block production and transaction inclusion are back to acceptable levels. We have deployed and confirmed reliability of several improvements to our block builder and transaction processing infrastructure, please reach out in discord with any issues.

Mar 24, 13:12 UTC
Update - Stability of block production and transaction inclusion are back to acceptable levels. We have deployed and confirmed reliability of several improvements to our block builder and transaction processing infrastructure, please reach out in discord with any issues.

Feb 6, 23:48 UTC
Monitoring - We continue to see improved network stability after updating several elements of our routing infrastructure and as overall market volatility has subsided. We will continue monitoring network health and transaction success rate, while working on further upgrades to routing and transaction propagation layers which we described below.

Several larger upgrades are deployed on devnets and testnets to ensure their stability under different network conditions, with plans to promote them to mainnet after we validate their safety. This remains our top priority and we'll continue to post updates with our ongoing progress.

Feb 6, 01:46 UTC
Identified - Update 2/6 01:30 UTC

Overview
We are actively scaling to meet elevated demand. While immediate infrastructure updates are underway to improve current throughput, we have also initiated several longer-term projects to ensure future stability and network performance.

What we did today
We’re landing changes to improve the RPC latency for eth_sendRawTransaction calls during load, and improve the efficiency of getting transactions to the block builder for selection:

* [Live on Mainnet] - Doubled the disk IO throughput of our txpool
* [Live on Mainnet] - Changed our `eth_sendRawTransaction` rate limiting window to smooth out incoming spikes. We will continue changing the rate limiting configuration in the coming days
* Built and tested a more stable routing algorithm for sending transactions to the most efficient backend. We expect this to be on Mainnet within a couple of days

What’s up next
This work is expected to take 4 to 6 weeks. We anticipate this work to achieve stable transaction inclusion and block production
* Implementing a transaction propagation redesign that removes the overhead of P2P when getting transactions to the block builder.
* Optimizing and scaling configurations for `pending` and `queued` storage of transactions
* Unifying the components of our block building, sequencing, and flashblocks streaming

We will share updates here as we make progress.

Feb 5, 15:22 UTC
Update - We are experiencing heavy transaction volume resulting in inclusion delays. Active fixes are in progress

Jan 31, 22:42 UTC
Monitoring - We are actively monitoring network conditions. During periods of high congestion, users may experience intermittent transaction delays or transactions dropped. Submitted transactions can occasionally take up to two minutes to be included in a block or may need to be resubmitted. We are working on longer-term fixes to ameliorate this behavior and will share our plans and updates as we make progress.

Flashblock websocket connection errors

Mon, 09 Mar 2026 21:54:16 +0000

Mar 9, 21:54 UTC
Resolved - This incident has been resolved.

Mar 9, 21:16 UTC
Monitoring - We are monitoring a fix that has been implemented.

Mar 9, 20:29 UTC
Investigating - Users connecting to the Flashblocks websocket (mainnet.flashblocks.base.org) may have trouble connecting and receiving flashblocks. Block production is unaffected. We are currently investigation the issue.

Base Mainnet minimum base fee increase

Thu, 19 Feb 2026 20:30:07 +0000

Feb 19, 20:30 UTC
Completed - The scheduled maintenance has been completed.

Feb 19, 19:00 UTC
In progress - Scheduled maintenance is currently in progress. We will provide updates as necessary.

Feb 18, 21:30 UTC
Scheduled - On Thursday, February 19th between 19:00 and 20:00 UTC, the minimum base fee on Base Mainnet will be increased from 2,000,000 wei to 5,000,000 wei. At current prices of ETH, transactions paying the minimum fee will cost less than a cent: approximately $0.002. For more information, see https://docs.base.org/base-chain/network-information/network-fees.

Sepolia block building issue

Wed, 18 Feb 2026 16:56:51 +0000

Feb 18, 16:56 UTC
Resolved - This incident has been resolved.

Feb 18, 07:16 UTC
Monitoring - A fix has been implemented and we are monitoring the results.

Feb 18, 05:31 UTC
Investigating - We are currently investigating the issue, blocks are being produced, but with no transaction included.

Base Mainnet Upgrade 18

Tue, 10 Feb 2026 18:00:09 +0000

Feb 10, 18:00 UTC
Completed - The scheduled maintenance has been completed.

Feb 10, 16:00 UTC
In progress - Scheduled maintenance is currently in progress. We will provide updates as necessary.

Feb 9, 18:23 UTC
Scheduled - Note: There are no hardforks activating during this upgrade, and no required upgrades to node software.

On Tuesday, February 10th between 16:00 and 18:00 UTC Base Mainnet will undergo Upgrade 18: https://docs.optimism.io/notices/upgrade-18.

This upgrade introduces Cannon + Kona fault proof support (including an optional switch to Kona proofs as the respected game type).

Mempool upgrade

Thu, 05 Feb 2026 20:00:21 +0000

Feb 5, 20:00 UTC
Completed - The scheduled maintenance has been completed.

Feb 5, 18:00 UTC
In progress - Scheduled maintenance is currently in progress. We will provide updates as necessary.

Feb 4, 23:04 UTC
Scheduled - There is no downtime for this maintenance.

As a followup from the Saturday 1/31 postmortem (https://status.base.org/incidents/zfvvgt46j9d8), we're improving the reliability of our backend mempool by reducing the variance in their configuration.

This migration will have no downtime. We expect improved transaction inclusion latency. However, this change is part of a broader set of infrastructure improvements designed to eliminate transaction drops and remove variance in inclusion times.

If you notice any problems with your applications, please reach out to the team in Discord.

Base Mainnet minimum base fee increase

Tue, 03 Feb 2026 03:30:21 +0000

Feb 3, 03:30 UTC
Completed - The scheduled maintenance has been completed.

Feb 3, 02:00 UTC
In progress - Scheduled maintenance is currently in progress. We will provide updates as necessary.

Jan 30, 16:01 UTC
Scheduled - On Monday, February 2nd between 9 pm and 10 pm ET (02:00 to 03:00 UTC on February 3), the minimum base fee on Base Mainnet will be increased from 1,000,000 wei to 2,000,000. At current prices of ETH, transactions paying the minimum fee will cost approximately $0.001. For more information, see https://docs.base.org/base-chain/network-information/network-fees.

High Rate of Transaction Drops and Transaction Inclusion Delays

Sat, 31 Jan 2026 21:51:55 +0000

Jan 31, 21:51 UTC
Resolved - We have validated the fix restored overall network stability. We will be conducting a full RCA and share a public postmortem in the coming days.

Periods of increased network congestion can still occasionally result in transactions being delayed or dropped - we are working on longer-term fixes to ameliorate this behavior and will share our plans and updates as we make progress.

Jan 31, 20:47 UTC
Monitoring - We have deployed a fix for the problem causing transactions to not propagate correctly to the block builder under load.

Transaction inclusion has improved; we're continuing to monitor the fix in order to ensure the problem is resolved.

Jan 31, 20:35 UTC
Identified - We are now seeing high failure rates in transaction processing by the txpool and block builder. Users will experience high rates of transaction drops from the txpool, as well as overall high transaction inclusion times.

We are actively troubleshooting this problem.

Jan 30, 23:05 UTC
Monitoring - We have identified an issue causing occasional dropped transactions during high-traffic periods. We have implemented a fix and are now monitoring the results.

Update 1/31: The fix is still being tested. We still have high rates of transaction distribution failures and continue to investigate solutions.

Jan 22, 22:19 UTC
Investigating - Base is experiencing intermittent transaction delays due to network congestion. Submitted transactions can occasionally take up to two minutes to be included in a block. We are actively working on a fix and expect this behavior to continue until it can be tested and deployed.

Base Mainnet minimum base fee increase

Thu, 22 Jan 2026 20:30:22 +0000

Jan 22, 20:30 UTC
Completed - The scheduled maintenance has been completed.

Jan 22, 19:00 UTC
In progress - Scheduled maintenance is currently in progress. We will provide updates as necessary.

Jan 21, 23:49 UTC
Scheduled - On Thursday, January 22nd between 19:00 and 20:00 UTC, the minimum base fee on Base Mainnet will be increased from 500,000 wei to 1,000,000 wei. At current prices of ETH, transactions paying the minimum fee will cost approximately $0.0003. For more information, see https://docs.base.org/base-chain/network-information/network-fees.

Periodically delayed block building on Base Mainnet

Tue, 20 Jan 2026 14:30:00 +0000

Jan 20, 14:30 UTC
Resolved - Base mainnet is experiencing periodically delayed blocks due to volatile activity. We're actively monitoring and working to improve the consistency of block building performance. Between 14:45 and 15:10 UTC on 1/20/2026, users may have noticed delayed transaction inclusion and degraded block building performance .

Base Mainnet minimum base fee and gasLimit increase

Thu, 18 Dec 2025 20:00:23 +0000

Dec 18, 20:00 UTC
Completed - The scheduled maintenance has been completed.

Dec 18, 19:00 UTC
In progress - Scheduled maintenance is currently in progress. We will provide updates as necessary.

Dec 16, 18:51 UTC
Scheduled - On Thursday, December 18th between 19:00 and 20:00 UTC Base mainnet will undergo the following changes:

Minimum base fee will be increased from 200,000 wei to 500,000 wei. For a typical transaction this fee will currently cost approximately $0.00015.

Additionally, the gasLimit will increase from 300_000_000 to 375_000_000 gas per block, along with an EIP-1559 elasticity increase to 6. This will result in only a minor increase in average throughput (gasTarget) from 60_000_000 to 62_500_000 gas per block.

Delayed Transactions

Tue, 09 Dec 2025 23:00:00 +0000

Dec 9, 23:00 UTC
Resolved - Base experienced a high rate of missed blocks. Transactions sent during missed blocks are delayed until the next successful block. The issue has resolved itself, and we've prepared a mitigation to put in place if the issue returns.

Base Mainnet Jovian upgrade on December 2nd at 16:00:01 UTC

Thu, 04 Dec 2025 18:25:02 +0000

Dec 4, 18:25 UTC
Completed - The scheduled maintenance has been completed.

Nov 25, 14:51 UTC
Scheduled - On Tuesday December 2nd, 2025 at 16:00:01 UTC (Unix timestamp 1764691201), the Base Mainnet network will undergo the Jovian upgrade.

Operators of Base Mainnet nodes must upgrade to the latest release of the Base node software here: https://github.com/base/node/releases/tag/v0.14.3

More information about the Jovian upgrade can be found here: https://docs.optimism.io/notices/upgrade-17

One of Jovian's key features is the minimum base fee. On Thursday, December 4, the minimum base fee for Base Mainnet will be set to 200,000 wei so we can gather data on how this affects the chain. We expect less than 5% of transactions to be affected by this change. Going forward, this feature will make it easier for us to raise the gas target and reduce the average base fee during high activity.

Jovian Upgrade on Base Sepolia Testnet November 19th at 16:00:01 UTC

Wed, 19 Nov 2025 17:00:21 +0000

Nov 19, 17:00 UTC
Completed - The scheduled maintenance has been completed.

Nov 19, 16:00 UTC
In progress - Scheduled maintenance is currently in progress. We will provide updates as necessary.

Nov 13, 21:50 UTC
Scheduled - On November 19th at 16:00:01 UTC, the Base Sepolia network will undergo the Jovian upgrade.

Operators of Base Sepolia Testnet nodes must upgrade to the latest release of the Base node software here: https://github.com/base/node/releases/tag/v0.14.1

More information about the Jovian upgrade can be found here: https://docs.optimism.io/notices/upgrade-17#breaking-changes-block-header-changes