Blockly v13.0.0 is available now

[Maribeth Moffatt]

Hello Block Builders! We have a very exciting release for you with v13.0.0! Highlights:

• Blockly is now both keyboard-navigable and screenreader-accessible by default! You can read more about our approach here. If you have custom blocks and/or fields, you'll want to update the aria roles and labels for those as described here. See below for more resources.
• If you were using the @blockly/keyboard-navigation plugin, you should uninstall it at the same time that you update to v13! Keyboard navigation is enabled by default.
• As usual, each of the breaking changes PRs linked below contains instructions for how to know if a change affects you and what to do if it does. Many of these breaking changes are quite niche so for many of you it should not be a huge lift to update. A big category of these is the addition of new keyboard navigation shortcuts. If these conflict with your existing shortcuts, you'll need to update one or the other. We recommend you keep our default keyboard navigation shortcuts if at all possible, to maintain parity with other block-based applications. Get in touch on the forum if you have questions!
• We updated the default renderer to thrasos. If you explicitly specify your renderer (as you probably should) then this does not affect you, but if not you may notice your blocks look very slightly different. Thrasos is more performant than geras so we recommend you keep using it if possible.
• We've added a new sound for when a block is dropped on the workspace. Our user testing validated that the new sound helped users understand when a new block is placed, in addition to the existing sound effect for when blocks are connected or disconnected. We know new sounds can be jarring but give it a chance :)
• We also updated the default location of sounds to blockly.com/media. Best practice is to host the sounds yourself, so if you're doing that be sure to also host the new sound. Or you can replace it with your own file if you prefer.
• The oldest browser we now support is Safari 15.4. This version is already no longer receiving security updates from Apple so we believe most applications should already have a minimum supported version newer than this. If this is an issue for you, you can polyfill the css :has selector and continue supporting older versions.
• Plugins are coming soon - we'll send another email when they're released. New this cycle is that all plugins will receive the v13.0.0 version number so it will be easy to tell how to update your plugins when required.

More accessibility resources:

• Be on the lookout for our Blockly Summit 2026 talks on YouTube which had tons of relevant talks! We'll post an update on the forum when these are live.
• Best practices for creating accessible applications
• How to audit your block-based app for conformance with accessibility requirements

See the full release notes on the GitHub release. And let us know if you have any questions or comments. Please file issues on GitHub if you notice any bugs. Thanks!

Maribeth on behalf of the Blockly team

[Maribeth Moffatt]

Whoops, here's the link to the GitHub release notes.

[Seb Seb]

Great !!!!! Very happy to see this work for accessibility, thanks a lot!

[Seb Seb]

Sorry, I forget... will you update the blockly factory (Blockly Developer Tools) to embed all this new features?