No matter how much you test, sometimes something slips through. 1.9.0rc2 is incoming due to the octoprint_setuptools refactoring breaking most plugin installs on 1.9.0rc1 after all. Sorry for the inconvenience, new RC asap1.9.0rc2 has been pushed to fix this!

Originally planned for late 2022, I’m happy to finally present you the first release candidate of the upcoming 1.9.0 release. Given how long this has been brewing, the changelog has grown quite large (Gist since 1.9.0rc1 had to be pulled). Let’s take a look at some of the highlights, shall we?

  • The Webcam integration now offers a plugin interface and the existing webcam support has been extracted into its own (bundled) “Classic Webcam” plugin. Third party plugins will now be able to offer new webcam providers for snapshots, and also webcam templates for embedding streams. This also includes native multi cam support in the core UI - if there’s more than one plugin providing webcam templates, they will be offered to switch to, see this GIF.
  • With 1.9.0 plugins can now customize the temperature chart markers introduced in 1.8.0, thanks to the work by @rfinnie, who also promptly utilized it in recent versions of his BedCooldown plugin as can be seen in the below screenshot.
  • Thanks to a ton of work by @JoveToo, the memory footprint of the GCODE viewer has been greatly reduced, thanks to utilizing (optional) compression and asynchronous loading of the data. This should make the GCODE viewer much more usable on lower end devices, and also make it possible to load larger files without running into memory issues.
  • While no printer connection is yet established, OctoPrint will now automatically poll for serial ports and if new ones are found refresh the UI accordingly. This should improve user experience, as you will no longer have to manually refresh the UI to see new ports (and potentially get rid of the “no ports detected” warning added in 1.8.0). Contrary to the PortLister plugin, this will also work on Windows servers and for any kind of virtual ports. You can see this in action below.
  • You can now enqueue plugin installs from the plugin manager thanks to work by @jneilliii.
  • The plugin manager now also supports installing mulitple plugins from an export or simple json list either uploaded or passed in as an URL. This should make it easier to install a bunch of plugins at once.
  • In a similar vain, you can also now upload multiple files at once, thanks to work by @cp2004.
  • Announcements will now no longer trigger a popup (unless from a priority 1 channel like Important) but instead cause an unread counter to be rendered on the notification icon (1-9 and infinity symbol for more). The announcement reader has been extended by a default “Unread” tab that shows all unread news items, and a Mark All Read button has been added to quickly get rid of the unread counter altogether.
  • As always, there have also been a ton of bug fixes. Examples include fixing the permissions of anonymous API access (they were too strict), including line endings when copy-pasting from the plugin manager or software update log output, and even more.
  • … and even more.

Please also take a look at the following heads-ups:

Heads-up: OctoPrint's web interface now requires ES9 (EcmaScript 2018) support in your browser

Up until now OctoPrint still supported running its UI on browsers that only supported EcmaScript 5 as released in 2009. However, given that based on data about used browsers from the Anonymous Usage Tracking 98.96% of all browsers used to access OctoPrint support ES9 and being able to use these features allows things like asynchronous GCODE loading in the viewer (see #4559) and in general very much improves development experience and speed, the decision has been made to greenlight the use of these features in OctoPrint’s JS code base.

Given that pretty much all common browsers have had the required support for several years now, this change should not affect ~99% of all of you. For those 0.15% of you accessing the OctoPrint web interface with ancient browsers that don’t yet have support this means it is time to upgrade. For those 0.89% of you accessing the OctoPrint web interface with browsers for which we do not know about support, it might also be time to upgrade.

In any case, you can check whether your chosen browser supports all the features that OctoPrint uses in core & bundled plugins by going to the new check page at

Heads-up for plugin and third party application developers: Webcam integration has moved to a plugin interface

OctoPrint 1.9.0 has been refactored to extract the webcam integration into a new plugin type WebcamProvider as well as a _webcam template type. You may find the documentation of these here:

A new bundled plugin Classic Webcam has been created that implements the existing webcam integration (mjpg/hls/beta webrtc support as well as snapshotting).

A consequence of this refactoring is that there’s no longer a general webcam configuration in the settings but rather now there are WebcamProviderPlugin specific settings per plugin. A backwards compatible compatibility layer has been added so that plugin’s accessing any of the formerly available global webcam settings should still be able to access and change the data, however it should be considered deprecated and warnings will be logged. Please check your plugins and adjust as necessary when running on OctoPrint 1.9.0.

Heads-up for plugin developers: `octoprint_setuptools` has been extracted

In order to support plugin’s that want to use pyproject.toml, in which case current pip versions will build their package in isolated mode, leading to the required octoprint_setuptools dependency not being available and thus the install failing, octoprint_setuptools was extracted into its own pypi package to allow pyproject.toml based plugins to depend on it by adding this to pyproject.toml:

requires = ["setuptools>=40.8.0", "wheel", "octoprint-setuptools"]
build-backend = "setuptools.build_meta"

This should not affect plugins that don’t use pyproject.toml, however like with every OctoPrint release candidate plugin developers are strongly advised to test installing their plugin under 1.9.0.

You can find the full changelog and release notes as usual on GitHub.

Special thanks to everyone who contributed to this release candidate and provided full, analyzable bug reports, you help making the next release as stable as possible!

A special Thank You! to these 25 fine people for their PRs, and an extra warm welcome to our 16 first-time contributors! 🎉

As the past RCs have shown me that a lot of people appear to be unaware of this: Please do not install this RC if you expect a fully stable version. It is not a stable release, it is a release candidate: severe bugs may occur, and they might be bad enough that they make a manual downgrade to an earlier version necessary - maybe even from the command line.

You should feel comfortable with and capable of possibly having to do this before installing an RC.

If you want to and can help test this release candidate, you can find information on how to switch to the "Maintenance RCs" release channel in this guide if not already done (also linked below).

Please provide feedback on this RC. For general feedback you can use this ticket on the tracker. The information that everything works fine for you is also valuable feedback 😄. For bug reports please follow How to file a bug report - I need logs and reproduction steps to fix issues, not just the information that something doesn't work so make sure to fill out all fields of the issue template.


Depending on the feedback regarding this version I'll look into fixing any observed regressions and bugs and pushing out a follow-up version as soon as possible and necessary.


Multiple registered webcam views can be switched in the Control tab.
The markers on the temperature graph can now be extended by plugins through a new event. Here you can see how the BedCooldown plugin by @rfinnie makes use of that to add a Cooldown marker.
The port list will now autorefresh while no connection the a printer has yet been established.
Announcements will no longer trigger a popup (apart from priority announcements), but rather show up as a counter in the navbar.
The announcement viewer has been extended by a "Unread" tab and a "Mark all read" button.