---
title: "ReactJS.NET 3.4 and 4.0 beta"
layout: post
author: Daniel Lo Nigro
---

I'm happy to announce the release of ReactJS.NET 3.4! This is a minor release with a few performance-related changes contributed by [Daniil Sokolyuk](https://github.com/DaniilSokolyuk):

 - [#529](https://github.com/reactjs/React.NET/pull/529) - Cache whether component names are valid.
 - [#528](https://github.com/reactjs/React.NET/pull/528) - Fast React ID generator.
 - [#532](https://github.com/reactjs/React.NET/pull/532) - Avoid large object allocations and reuse everything.

A few other changes have also been included. Thanks to Dustin Masters for most of these changes:

 - [#558](https://github.com/reactjs/React.NET/pull/558) - Fix crashes related to loading React 16.4.1
 - [#541](https://github.com/reactjs/React.NET/pull/541) - Use `ReactDOM.render` rather than `ReactDOM.hydrate` for ClientOnly components. *Thanks to [Suhail Ansari](https://github.com/suhailnaw) for his first open-source contribution! :)*
 - [#537](https://github.com/reactjs/React.NET/pull/537) - Added benchmarking tool for benchmarking changes to ReactJS.NET itself.

ReactJS.NET 4.0 beta has also been released. This release includes all the above changes, and also upgrades JavaScriptEngineSwitcher to 3.0.0 beta. Upgrade instructions can be found in the [How to upgrade applications to version 3.X](https://github.com/Taritsyn/JavaScriptEngineSwitcher/wiki/How-to-upgrade-applications-to-version-3.X) document.


Have fun, and as always, please feel free to send feedback or bug reports
[on GitHub](https://github.com/reactjs/React.NET).

— Daniel and Dustin
