In the world of Ethereum,
There is a crucial concept, which is Gas.
It is like fuel in real life,
Driving every transaction and the operation of smart contracts.
But do you know
What is the Gas limit?
Why does it change?
What different results could arise if the Gas limit is too high or too low?
This article will help you understand some aspects of the Gas limit.
What is Gas?
Gas is the unit used in the Ethereum network to measure the computational resources required to execute operations. Whether it is a simple Ether transfer or triggering the execution of complex smart contracts, every operation requires Gas consumption.
For example, a typical Ethereum transfer transaction usually consumes 21,000 Gas, while smart contract operations involving complex calculations and state changes may consume hundreds of thousands or even more Gas.
What is the Gas limit?
The Gas limit is a key parameter in the Ethereum blockchain network, specifying the total amount of Gas that each block can accommodate.
The creator of each block (miner or validator) must ensure that the total amount of Gas consumed by all transactions within that block does not exceed the Gas limit. The Gas limit determines the number and complexity of transactions that each block can include.
Is Gas Limit the same as Gas limit?
The two are different parameters.
The Gas Limit is the upper limit set for the Gas consumption of a single transaction, determined by the user when initiating the transaction. It represents the maximum amount of Gas the user is willing to pay for this specific transaction or smart contract execution.
The Gas limit on the Ethereum network is a restriction on the total Gas consumption of all transactions within an entire block. It determines the maximum amount of Gas that can be processed in each block.
The Gas Limit of each transaction is part of the total Gas limit. If the total Gas Limits of all transactions exceed the network Gas limit, then these transactions cannot all be packaged in one block, and some transactions will need to wait for the next block or increase the Gas Price to gain priority for packaging.
When the Gas limit is too low
The Ethereum network can quickly become congested like a narrow road flooded with too many vehicles.
Due to the limited total number of transactions that can be accommodated in each block, a large number of transactions can only wait to be packaged, significantly extending confirmation times. To have their transactions processed first, users are forced to increase transaction fees, raising transaction costs, which heavily burdens small and high-frequency traders.
This not only reduces user experience, leading to some user attrition, but also obstructs the development of decentralized applications and smart contracts. Complex contracts fail to execute due to insufficient Gas, discouraging developers and severely impacting the expansion and innovation of the Ethereum ecosystem.
When the Gas limit is too high
While it can accommodate more transactions, it may also pose some hidden dangers to the Ethereum network.
The block size increases due to the increase in transactions and data, putting more strain on network bandwidth and node storage, leading to delays in data synchronization and even node disconnection.
At the same time, a high Gas limit reduces decentralization, making it difficult for small nodes to participate, increasing the influence of a few powerful nodes, raising security risks, and making it easier to suffer malicious attacks.
Additionally, it may lead to resource waste, as developers write inefficient smart contracts and do not focus on optimizing Gas usage, reducing the efficiency of network resource utilization, which affects the long-term sustainable development of Ethereum.
Why increase it?
As the Ethereum ecosystem continues to develop, with more and more applications and transactions flooding in, the lower Gas limit often leads to issues such as transaction congestion and soaring fees, posing challenges to user experience and further development of Ethereum.
A higher Gas limit means that the Ethereum network can accommodate more transactions, allowing each block to package more data, thereby increasing the network's transaction processing capacity. This is undoubtedly a significant benefit for various decentralized applications (DApps), smart contracts, and numerous users on Ethereum. It can alleviate transaction congestion, reduce users' transaction fees, and enable the Ethereum network to better support large-scale commercial applications and high-frequency transaction demands.
After the increase, Gas fees may decrease
When the Ethereum Gas limit is raised, it is like widening traffic roads, allowing each block to accommodate more transactions. In cases where transaction demand is stable or grows slowly, the intense competition for transactions that was previously due to tight block space now experiences significant relief. Users no longer need to compete by raising Gas prices to have their transactions packaged quickly, just as vehicles no longer need to pay high costs to compete for limited parking spaces. Therefore, from the perspective of supply and demand, it is likely that Gas fees will decrease with the availability of transaction space, providing users with a more economical transaction experience.
After the increase, Gas fees do not necessarily decrease
Although the Ethereum Gas limit has been increased, Gas fees do not necessarily decrease. The Ethereum ecosystem is full of variables; if new popular applications continuously emerge, attracting a large influx of users, transaction demand is likely to experience explosive growth, far exceeding the capacity that the increase in Gas limit can accommodate, resulting in continued network congestion. Additionally, the instability of network activity, miners' (validators') strategy adjustments based on their own interests, and the high consumption characteristics of new applications regarding Gas can also keep Gas fees high or even increase them further, so a reduction in Gas fees is not guaranteed.
Gas limit from 2015 to 2019
From 2015 to 2019, the Gas limit of Ethereum underwent multiple adjustments to accommodate the growth in network transaction volume and the development of decentralized applications (DApps).
In 2015, when Ethereum launched, the initial Gas limit was 5,000 Gas per block.
In 2016, the Gas limit was first raised to about 3 million, and later in the same year, during the Tangerine Whistle hard fork (EIP-150), the Gas limit was increased to 5.5 million to address DoS attacks.
In July 2017, the Gas limit was increased to 6.7 million and further raised to about 8 million in December of the same year.
Significant historical increase: Istanbul hard fork (December 2019)
In the Istanbul hard fork, Ethereum raised the block Gas limit from 8 million Gas to 10 million Gas.
During this period, the number of decentralized applications (DApps) on Ethereum gradually increased, and user demand for transaction processing capacity began to rise. Increasing the Gas limit can alleviate transaction congestion to some extent, allowing each block to accommodate more transactions, enabling the network to better adapt to the growing transaction demand and providing a more favorable environment for the development of DApps.
Significant historical increase: May 2021
In May 2021, the Gas limit was raised from 15 million Gas to 30 million Gas.
During this period, with the rise of DeFi (Decentralized Finance) and NFTs (Non-Fungible Tokens), network transaction volume increased significantly, leading to congestion and soaring Gas fees. To alleviate this issue, the Ethereum community decided to raise the Gas limit.
At that time, Ethereum developers, researchers, and community members proposed corresponding technical solutions after extensive discussion and research, and implemented the adjustment of the Gas limit through hard forks. A hard fork means that a permanent divergence will occur in the blockchain network, and old nodes need to upgrade to the new version to continue participating in the network's operation.
This was the last major adjustment of the Ethereum network under the PoW (Proof of Work) mechanism. This adjustment doubled the Gas limit, significantly enhancing the network's transaction processing capability.
EIP - 1559 London hard fork, August 2021
EIP - 1559 was activated during the London hard fork. Although the core of this upgrade was to change Ethereum's transaction fee mechanism, it also had an indirect impact on the Gas limit. Prior to this, miners could adjust the Gas limit themselves based on market conditions.
EIP - 1559 introduced the concepts of base fee and tips, while setting a target Gas usage (usually corresponding to a certain Gas limit). The network dynamically adjusts the base fee based on transaction demand, aiming to bring each block's Gas usage close to the target value. This mechanism standardizes and automates the adjustment of the Gas limit to better balance the network's load and transaction fees.
This increase: February 2025
Ethereum network, for the first time under the PoS mechanism, successfully raised the block Gas limit from the previous 30 million to over 31 million Gas with support from more than 50% of validators, and as of February 4, it has been adjusted to over 33.5 million Gas, with expectations to ultimately adjust to 36 million Gas.
On February 8, it was reported that, according to a technical update forwarded by Vitalik, Ethereum L1 completed the dynamic adjustment of block Gas limit, increasing it from 30M to 36M Gas.
Under the PoS mechanism, validators play a crucial role in the network, responsible for validating transactions and packaging blocks. The reform can only proceed smoothly when the majority of validators reach a consensus to support the adjustment of the Gas limit.