MEV Boost is open source middleware for Ethereum validators that want access to a competitive block-building market. It is built for people who already run proof-of-stake validator infrastructure and want a practical way to receive block proposals from multiple builders instead of relying on a single source. If you are looking to download MEV Boost for Windows, this page covers what it does, how to get the official build, and what to check before you run it.
The project is free, released under the MIT license, and written in Go. Each release ships binaries for Windows, macOS and Linux, and Docker is also listed as a platform. The current release is marked v1.12-alpha1, and the code was last updated on June 30, 2026, so the project is active but still pre-release. Read on for setup steps, configuration options and a plain-language look at the category.
How Proposer-Builder Separation Works
Proposer-builder separation, usually shortened to PBS, splits two jobs that are normally handled by one party. A builder assembles the contents of a block, choosing transactions and ordering them to capture value. A proposer, the validator whose turn it is to publish the block, picks the best offer it receives and signs it.
Maximal extractable value, or MEV, is the extra revenue that can come from ordering transactions inside a block. Without a separation, validators may capture that value themselves or hand it to a single intermediary. PBS creates an open auction where several builders compete to offer the most valuable block.
MEV Boost is an early implementation of this idea for proof-of-stake Ethereum. Understanding the model helps you read the rest of this page, because every setting in the software affects which bids reach the validator and how they are selected.
Who Should Consider Running MEV Boost
MEV Boost is aimed at operators who already run or plan to run an Ethereum validator. It is middleware, which means it works alongside your validator setup rather than replacing it. It sits in the path that delivers block proposals, so it suits people who are comfortable with command-line tools and reading logs.
Solo stakers who want more control over their block proposals will find the minimum bid and log level options useful. Operators who manage several validators may care more about hot reloading, since changing a threshold across a running setup can be done without stopping every process.
Casual holders who only want a simple staking interface usually do not need to think about this layer. Their staking provider may already handle block production choices on their behalf, so running MEV Boost yourself is a decision for technically confident validator operators.
What Is a Minimum Bid and How Should You Set It?
A minimum bid is the lowest payment a validator will accept for a block offered through a relay. The threshold works as a filter. A higher value screens out small offers but leaves fewer offers that qualify, while a lower value accepts more of them. The right level depends on how much revenue matters to your setup and how much risk you are willing to accept.
Relays are intermediaries that pass block offers from builders to validators. Which relays you trust is a separate decision, and it deserves its own research before you configure anything. A minimum bid cannot fix a relay you do not trust.
The documentation uses an example of 0.06 ETH to show how the flag is written. That number illustrates the format and is not a recommendation. Test changes on a non-critical setup, and watch the logs at info or debug level to see how often offers are filtered out.
Key features
Competitive block-building access
Minimum bid control
Adjustable log levels
Hot reloading of configuration
Cross-platform builds
Supported coins
MEV Boost is built for Ethereum (ETH) and its proof-of-stake validator model. Its documentation names Ethereum as the network it targets, and its role stays focused on the block production step of Ethereum staking.
How to install MEV Boost on Windows
- 1
Open the official release page
Go to the flashbots/mev-boost project on GitHub and open the Releases section. Download only from the official website or the GitHub Releases page. The most recent release is v1.12-alpha1, a pre-release, and each release includes a Windows binary alongside Linux and macOS builds.
- 2
Verify the file
Check the SHA-256 checksum of the downloaded archive against the value published with the release. If the release provides a signature, verify it as well. Do not run a file whose checksum does not match the published value.
- 3
Place the binary in a folder
Unpack the download into a dedicated folder for validator tools. Keeping the binary and its config file together makes the -config option easier to manage later, and it keeps your launch commands in one predictable place.
-
Set launch options and test
Open Command Prompt or PowerShell in that folder and run the binary with the options you need, such as -min-bid. Start with the default info log level, watch the output for a few minutes, and only then change settings one at a time.
System requirements
- Windows, using the Windows binary included in the official release
- Command-line access to pass options such as -min-bid and -config
- An Ethereum validator setup, since MEV Boost is middleware run by validators
How to use MEV Boost
MEV Boost runs from the command line, so the workflow is about passing the right options at launch and checking the output. The steps below assume you have already unpacked the Windows binary.
- Open PowerShell or Command Prompt in the folder that contains the mev-boost binary.
- Decide on a minimum bid and add it with the -min-bid option. Write the value in the same format as the documentation example of 0.06 ETH.
- Choose a log level with the loglevel option. Use info for routine running, and switch to debug or trace only when you troubleshoot.
- If you keep your settings in a file, add -config followed by the file path so the program can read it.
- Enable hot reloading for that config file while the program runs. Edit the file, save it, and confirm in the logs that the new values were applied.
- Keep watching the output for relay activity and errors. Stop the program before making any change you cannot easily reverse.
Pros & cons
- Free to use under the MIT license
- Open source code that anyone can inspect on GitHub
- Adjustable minimum bid threshold for each operator's own risk level
- Configurable log levels for everyday running and troubleshooting
- Supports hot reloading of config files on a running setup
- Windows binaries are included in each release
- The latest release is a pre-release marked v1.12-alpha1
- Built for Ethereum validators, so it has no use for general crypto users
- Requires comfort with command-line setup and validator operation
- Detailed guidance lives in an external wiki rather than inside the program
Is MEV Boost safe?
MEV Boost is not a wallet, but it sits in the path of validator operations, so treat it with care. Download only from the official website, which for this project is the GitHub Releases page of flashbots/mev-boost. Verify the SHA-256 checksum or signature of the file before running it, and never run a copy obtained from a forum, a chat message or an unknown mirror.
Never enter a seed phrase or validator key material into a third-party website or into any tool you cannot verify. Because the latest release is an alpha, expect changes between versions and check the latest version on the official website before you install or update.
- Official source only. Download from github.com/flashbots/mev-boost. Ignore ads and lookalike domains.
- Check the SHA-256. Compare the installer hash with the value the developer publishes before running it.
- Never share your seed phrase. No developer, support agent or website — including CryptApps — will ever ask for it.
Alternatives
MEV Boost has a narrow focus. It handles block production for Ethereum validators, while the other programs in this catalog cover different jobs. Trueblocks Core, for example, focuses on giving developers and analysts better access to blockchain data on EVM-compatible chains, including Ethereum mainnet. That makes it a tool for reading and querying chain history rather than for taking part in block building.
Randomx is a proof-of-work algorithm, a different consensus model from the proof-of-stake design that MEV Boost serves. If your goal is staking infrastructure, MEV Boost is the more relevant choice. If your goal is analyzing blockchain data, start with Trueblocks Core.
Specifications
- Price
- Free
- Type
- Open source
- License
- MIT
- Latest version
- v1.12-alpha1
- Last update
- 30 Jun 2026
- Windows support
- Yes (Windows build or installer)
- Source code
- github.com/flashbots/mev-boost
Frequently asked questions
MEV Boost is open source middleware that Ethereum validators run to access a competitive block-building market. It implements proposer-builder separation for proof-of-stake Ethereum, letting validators receive block offers from builders rather than assembling every block themselves. It is aimed at validator operators rather than casual users.
Yes, MEV Boost is free and released under the MIT license. Its source code is public on GitHub, so you can read it before you run it. Free software does not cover the cost of running a validator, which is a separate matter you should plan for on your own.
Yes. Each release includes a Windows binary alongside Linux and macOS builds, and the project also lists Docker as a platform. On Windows you run the binary from a command prompt and pass options such as the minimum bid setting.
The latest release is marked v1.12-alpha1, which means it is a pre-release. Pre-release software can change between versions and may contain issues that a later stable release would fix. Operators with significant stake should test thoroughly on a non-critical setup first.
The minimum bid setting, entered with -min-bid, sets the lowest value you will accept for a block from a relay. Offers below the threshold are filtered out. Choosing a value is a judgment call based on your revenue goals and risk tolerance, so test changes carefully before relying on them.
Hot reloading lets MEV Boost pick up changes from its config file while it runs. You must start the program with the -config option pointing to that file. After you edit and save the file, check the logs to confirm the new values were applied.
Verdict
MEV Boost suits Ethereum validator operators who want a free, open source way to access a competitive block-building market on Windows, Linux or macOS. It rewards careful setup, close reading of logs and a cautious attitude toward pre-release software. If you are a casual holder or you do not run a validator, this program is probably not for you. Start on a non-critical setup and expect to spend time learning the options before you rely on them.