Selenium 4.51 Released!

Today we’re happy to announce that Selenium 4.51 has been released!

By Diego Molina @diemol | Friday, October 09, 2026

Selenium 4.51 Released

[Java] Guava is no longer a dependency of the client bindings, so ExpectedCondition no longer implements Guava’s Function interface. See how to migrate if your code relies on it.
[JavaScript] The browser atoms, now written in TypeScript, are published as a standalone @selenium/atoms npm package, and the obsolete WebSQL and AppCache atoms were removed.
[Python] Added support for Python 3.15.
BiDi code generation keeps growing: Java gained a BiDi code generator, JavaScript can generate vendor specific classes, and the Firefox vendor CDDL is now pinned from the Firefox repository.
[JavaScript] The driver can install and uninstall web extensions through BiDi, falling back to the classic commands when BiDi isn’t available.
[Java] Added RemoteWebDriver.getClientFactory(), and the removal of the deprecated HttpCommandExecutor fields was postponed to 4.53 to give users more time to migrate.
[Build & Infra] Java artifacts are now signed in-process, and the release workflow can recover from an incomplete Java release.

Removed Guava from the client bindings; ExpectedCondition no longer implements Guava’s Function interface (migration guide).
Added RemoteWebDriver.getClientFactory() and moved the HttpCommandExecutor field removal to 4.53.
Stopped leaking the HttpClient when the driver fails to start.
Stopped passing a bare --proxy argument to Selenium Manager.
Added a BiDi code generator, decoded nested RemoteValues from the parsed tree instead of re-serializing each subtree, and typed field-less synthetic map records as Map<String, V>.

Escaped the Edge browser path on macOS.
Upgraded the test suite to NUnit 5, moved the NUnit infrastructure to its own project, and ran the internal tests in parallel.

Published the TypeScript atoms as the @selenium/atoms npm package as part of the npm release.
Removed the WebSQL and AppCache atoms.
Added driver methods to install and uninstall web extensions with BiDi, with a classic fallback.
Added vendor specific class generation for BiDi.

Degraded to empty metadata when the cache can’t be read, instead of failing.
Configured the Chrome sandbox after unpacking a Chrome for Testing build on Windows.

Signed Java artifacts in-process with in-memory PGP keys instead of gpg-agent.
Recovered from an incomplete Java release by dropping staged repositories, and generated release docs at approval time, committing them once the packages are published.
Pinned the Firefox BiDi vendor CDDL from the Firefox repository.
Sourced the Java and .NET versions from a root version.bzl, added a stub mode for using Selenium Manager with Bazel, and pinned the driver location once per test process.
Removed obsolete third party dependencies, Bazel patches with upstream fixes, and IntelliJ project files.

We thank all our contributors for their incredible efforts in making Selenium better with every release. ❤️

For a detailed look at all changes, check out the release notes.