The GLES3 renderer is already in master, but it's pretty broken and missing a ton of features. Not usable for 3D right now, maybe for a simple 2D game, I don't know. If you build master from source, you can run the Godot 4.0 editor from the command line with this option.

--rendering-driver opengl3

Is there a software renderer for Windows ?

On Linux, the MESA libraries have lavapipe for Vulkan and llvmpipe for OpenGL. Which make me think of a low consumption PC with onboard graphics for development.

Will say: Godot 4.0 alpha 10 runs with the lavapipe renderer. At least it starts. If such a thing is available for Windows, it may be a (probably terribly sluggish) workaround until better hardware can be obtained.

Edit: False alarm. It was only the entry screen that obeyed to manual gpu selection. The Editor reported use of the GPU.

    I've tried lavapipe, Godot 4.0 does open, but it's basically not viable. I tried even some 2D stuff and it was so slow I could not use the editor properly and then it eventually crashed. In any case, if your computer is so old it doesn't have Vulkan support, then there is little chance it is fast enough to software render.

    Pixophir Is there a software renderer for Windows ?

    Yes, you can try SwiftShader, which is a cross-platform CPU implementation of Vulkan. I haven't tried it, but my guess is it would be too slow for serious development. Though perhaps for some simple 2D or PSX-style 3D it would be enough.

    https://github.com/google/swiftshader

    Understood. So that's why it says "lavapipe is not a conformant Vulkan implementation. Testing use only." :-)

    Thanks. Well, not for me, I was thinking about a workaround for the OP's or possibly other venerable entry level graphics hardware.

    The cheapest new GPU you can buy, that supports all the latest standards is the RX 6400.

    https://www.newegg.com/asrock-radeon-rx-6400-rx6400-cli-4g/p/N82E16814930068

    It's honestly a pretty weak card, but it's cheap, and for development of lower-end games it's probably okay (like I'm saying 2D games or classic 3D). However, you need a desktop computer and it looks like the OP is on a laptop. So their only option would be to buy a whole new laptop, which I would say is not a good idea to test alpha software. Godot 4.0 may be a year away from release, so it would make more sense to upgrade when it actually comes out (especially considering that GLES3 support may work by that time). Also, Godot 3.x still works fine and may be supported for another 2 years or who knows how long. So I think it would be premature to spend a bunch of money right now.

      All duly noted.
      for the noob indies (like me) ,which suck and filter info slow, it was enlightening for the recent developments.
      Now, I am aware about the possibilities and I can arrange the wide path to proceed regarding hardware, software, mobile market.

      Thank you for your intensive interest.

      cybereality The cheapest new GPU you can buy, that supports all the latest standards is the RX 6400.

      https://www.newegg.com/asrock-radeon-rx-6400-rx6400-cli-4g/p/N82E16814930068

      If one's really on a budget, there's always the gt 1030(gddr version) for ~ 95:
      https://www.newegg.com/gigabyte-geforce-gt-1030-gv-n1030oc-2gi/p/1FT-000A-000G5

      But if you go scouring the right places you might be able to score a used RX 470 for about the same price, so I'd go for that instead. Either ways you're going to end up with a vulkan capable gpu that is multiple generations newer than what you must currently have if your current gpu doesn't even support vulkan.

        cybereality Godot 4.0 may be a year away from release, so it would make more sense to upgrade when it actually comes out (especially considering that GLES3 support may work by that time)

        this also makes sense considering how technology gets cheaper every year:

        1 year ago i had bought a laptop for school. it costed 800€ and it's stronger than the 3-year-old (or older) tower i still use at home that had costed 1000€ when i got it as a christmas gift.

        2 or 3 years ago i had bought my computer monitor for 500€. it has a 34cm tall SRGB screen with a reesolution of 1920×1080px and a refresh rate of 60Hz. now i have heard reports that some equivelant screns today cost only 300€.

        Megalomaniak If one's really on a budget, there's always the gt 1030(gddr version) for ~ 95:

        It's not worth it even if it was free. I bought one a few years ago just for testing and it's worse than Intel integrated iGPU. You can barely run 720P 30FPS.

          cybereality I bought one a few years ago just for testing and it's worse than Intel integrated iGPU. You can barely run 720P 30FPS.

          And yet it's a viable option for a vulkan capable gpu and a noteworthy improvement if you are using a gts 240 or something, but as I said, I'd rather try to find a used gpu that would be in the same price range but significantly better if I was in that situation. Such as an RX 470 4gb, they do occasionally move in that same price range, if you know where to look(such as tech enthusiast forums that have a second hand trade section).

          Yes, though if you are going to spend money at least get something that can run at 1080p with low/medium settings. An RX 470 is pretty good and around equal to the RX 6400. Both can do 1080p. Personally, I like buying new, but I see you can get an RX 470 for around $100 on eBay so that's not a horrible deal.

          in 2021 i had bought an AMD RX 550
          because i experienced bad graphics support on Linux with the pre-installed NVidia GTX 750
          and read reports that AMD is the brand with the good Linux support.
          at the time i had recently installed Linux on the old tower because it could barely run Windows 10 anymore.

          for me it's not a big deal because i fulfilled my goal of better system stability in general, but i can't run Godot 4 (and i still can't run Gdot 4 alpha 11) with the AMD card.

          writing this comment, i have the feeling that Godot 4 not starting has nothing to do with graphics.
          here is the error log — as a screenshot because it has color:

          should i post this error in a issue on Godot's main GitHub repository?

          @Sosasees the issue is clearly with pulse audio and the relevant libraries mentioned at the top, libasound.so and libpulse.so

          Also, it seems to be finding a project(from 3.x I presume) that it fails to find a compatible project.godot file for. As for posting on github, the latter I believe to be a known issue, but perhaps I'm wrong. Search before you post a new issue, that should be the modus operandi always tho.

            Godot, in general, has all sorts of issues if you start without audio support. This will happen, even with an audio output device, if you, for example, launch Godot with the speakers or headset turned off, then you get those messages. They should not be an issue either but it's worth looking at.

            the closing reply in the GitHub issue said
            that Godot 4 not starting has nothing to do with any of the messages.
            it crashed because Debian 10's Vulkan Driver is unstable.
            after upgrading to Debian 11, i can now start Godot 4 without errors.

            Well, not nothing to do with it. The audio library messages were also likely in response to the debian 10's libraries being too old.

            Yeah, Debian's strength lies in stability, not necessarily in the latest features. But with the AMD proprietary driver it should have worked. I'm actually using Debian unstable now because of ray tracing support in the open source RADV driver. Maybe this feature is in testing, meanwhile. It's bean more than half a year since I last checked ...