Any good tools for generating world maps and land masses?

Basically wondering if there are any good tools for generating world maps, mostly looking for something that can simulate plate tectonics and generate realistic mountain ranges and rivers and different biomes, just something that can generate a landmass that would be a good start to start populating with cities and points of interest.

Just curious what tools other DMs are using?

Inkarnate has a button to create a random map. Iirc, it’s just landmasses, you have to fill them in/make adjustments to them, but it can be a start. At least on the free version. Not sure what the paid version might do for you. 

I've been thinking of buying Wonderdraft (for world maps) or Dungeondraft (for dungeons and smaller encounters). AFAIK they are paid only (haven't checked if they have a free trial), but it's a single payment, no subscription. But according to adequate Googling, they've received good feedback.

As for just random generation, there's also Azgaar's Fantasy Map Generator, which is a free open-source web based map generator.

Inkarnate is capable of creating the maps you need, but like most things in life has a learning curve. No automatically generated maps are going to give you what you need short of highly niche pieces of software. Wonderdraft is also good if you intend to learn how to use it. One is a minimal £25 per year subscription; the other is a one-time purchase equal to a few years' subscription costs to get hold of everything.

Your genuine best bet if you want something specifically realistic is to pick a piece of software and learn how to use it well. That way you get to ensure that the map is as accurate as you wish it to be. Generative software is universally garbage for anything outside of the narrow purpose it was designed for.

How realistic does it need to be? Do any of your players have degrees in Geology that would mean they will notice and be annoyed if the plate techtonics is wrong? IIRC most fantasy maps are not at all realistic but then they were created by gods and crazy magic not mundane plate techtonics. 

Quote from Agilemind >>

How realistic does it need to be? Do any of your players have degrees in Geology that would mean they will notice and be annoyed if the plate techtonics is wrong? IIRC most fantasy maps are not at all realistic but then they were created by gods and crazy magic not mundane plate techtonics. 

Basically I am trying to do a bigger more comprehensive world building project, not just for a single game. I understand it is fiction and not everything has to be realistic but I think understanding how things form and using that knowledge to inform your world and how it evolves leads to more interesting a believable stories, good realistic map creates good conflict and good stories

I get it does not need to be 100% realistic but I just want to increase my understanding of these things and the more accurate the better

If you just googled your question you could find: https://devotegames.itch.io/geographically-accurate-planet-simulator

But if you actually want to learn something, CrashCourse has a whole series on Geology, and National Geographic has a whole series of articles on geological processes which I highly recommend. 

To generate a realistic map you will need to do the following, and learn about the relevant topics as you go via Wikipedia, National Geographic, PBS or BBC articles & documentaries:

1. Decide the size of your planet, it's tilt and planetary spin. 

• The tilt will affect the seasons your planet experience in different locations.
• The spin affects the length of a day, the Coriolis effect (which affects dominant wind direction), and tides

2. Decide on which parts of your planet are covered in continental crust (lighter oxygen-rich stone) vs ocean floor (heavier metal-rich), and draw the size & shape of your techtonic plates.

• Continental crust is generally the stuff shallow enough to be relevant to your fantasy civilizations whereas the ocean floor will be completely unknown to them and only affects your plate techtonics.

3. Move your plates around, ocean floor always sinks under continental crust. Look up: rift valley, rift zone, plateau, and mountain formation on wikipedia. Watch the MinuteEarth video on plate techtonics. 

• Then apply erosion, and move them again in a different direction, and repeat at least 3 cycles of this. This is important so that you have mountains of different ages, e.g. the Appalacia mountains are very old, eroded mountains whereas the Himalayas and Rockies are young mountains. 

4. Add a recent Ice Age (this is important if you want your planet to feel earth-like to your players but not if you are making a more alien planet). Look up: glacial erratic, glacial erosion, glacial lake, glacial deposition. The National Park Service has a great series of articles on glacial effects on the landscape as most of the most dramatic and picturesque landscapes in upper 48 states are formed by glaciers.

• Draw out the paths of the major glaciers starting in the north and at the tops of mountains down towards the south and lower lying areas. Then have them melt and if they were on top on ancient mountains they should leave millions of tiny lakes (see Minnesota or Ontario), if they were on flat land they should scape it bare leaving thin soil giving rise to taiga and steppe biomes.

5. Using the latitude and intensity of solar radiation (and atmospheric composition), determine the latitudinal temperature bands of your planet. This can be found under "Geographical zone" on Wikipedia.

• Don't forget to account for the temperature effects of extreme altitude which can be found on Wikipedia under Lapse Rate. 

6. Add in the climatic cells such as the Hadley Cells within each of these zones. NASA has a nice article about it. And determine the dominant wind directions across your planet.

7. Using the dominant wind directions and oceans & altitude maps above determine the average precipitation maps. Look up the concept of "Rain shadow".

8. Using the precipitation & altitude maps, draw on the drainage basins. Use these drainage basins to create major rivers and lakes (in addition to the glacial lakes mentioned previously).

9. Combine the precipitation, altitude, wind, and temperature to Köppen climate classification of each region of your planet.

10. Determine the density of habitation and general living styles that are viable across your planet based on these climate classifications - i.e. where is agriculture possible? where is herding more viable than agriculture? where is fishing sufficient to sustain populations? 

11. Using the dominant winds, and water features, determine the viable trade routes for your populations.

12. Combining the viable trade routes and the areas most suitable for dense habitation (i.e. high agricultural fertility) determine where major civilizations are likely to arise.

• Use geographic barriers such as large deserts or mountain ranges, to split habitation into linguistic groups & cultures.

13. Use your plate techtonics to situate volcanos and create historical natural disasters such as major earthquakes, and volcanic eruptions.

• Use drainage basins and topography to determine major floods, and landslides, that might have spawned myths and legends.

14. Use the harshness of climate & frequency of natural disasters to inform the cultures living next to them.

• Places with hard weather and frequent natural disaster generally believe in gods that are pernicious or at least quick to anger and that need to be appeased in someway to stop them destroying everything, whereas those that live in safety and abundance tend to believe in generous loving gods.

15. Determine the level of technology available to your cultures to determine the extent of each one's knowledge of their own planet, and the overall geography.

• Remember; Europeans and the first peoples of the Americas had no idea of each others existence until giant sea faring ships were invented.

Inkarnate is definitely the tool you want. I'd also highly recommend checking out the video tutorials that they post. For example their video on Top Down mountains is actually fairly good and a great demonstration of how precise and accurate you can get with their tool. https://www.youtube.com/watch?v=Dr330rpsiz0

As I mentioned earlier though, it requires you to learn the tools and use them.