exfret's randomizer

by exfret

Randomizes game properties, like belt speeds, inserter speeds, and more. Over a hundred game properties are touched. Download for the ultimate randomization experience that will force you to think in different new ways!

7 days ago
2 years ago
Latest Version:
0.2.12 (7 days ago)
Factorio version:
Downloaded by:
3.23K users


WARNING: Do not update this mod mid-run! Unfortunately, I am a single person working on this and not particularly known for making stable, compatible releases. I also am looking to overhaul the randomization process in the future, which would change everything.

If you run into any issues (or have suggestions), post in the Discussion tab of this page, or join my discord! https://discord.gg/ebHX7Yek9T


If you came here for the link to the properties spreadsheet for overrides, here it is: https://docs.google.com/spreadsheets/d/197McGR_7onmQJy4FRb207Owgaax0KpNFrHm_ZKFel8A/edit?usp=sharing


As featured in prominent youtuber DoshDoshington's video... https://www.youtube.com/watch?v=GlPREQ55kzc

I present, exfret's Randomizer

This mod randomizes various game properties, like belt speeds, inserter speeds, bot flying speeds, cliff sizes, and so on. Yep, you heard me, even cliff sizes can be randomized by checking a mod setting! Listing everything that's randomized would be difficult, since after two years of development, this mod now touches over a hundred different in-game properties.

With this mod enabled, you will be forced to reconsider many aspects of your build. If burner mining drills get randomized to 0.6 speed and electric mining drills to 0.3 speed, do you switch to burner mining drills? What if fast belts actually have terrible underground distance despite their increased speed? How do you deal with these inserters that take items from three tiles away??

Can you come up with creative solutions to the problems the randomizer throws your way before you lose your sanity completely?


  1. Balanced randomization (Sorta) Every property has been tested and fine-tuned so that the game is still completable and interesting. (I may have missed some things, please report anything egregious in the Discussion tab on on my discord).

  2. Personalized settings Choose which properties you want randomized or not, with more customization settings on the way!

  3. Consistent randomization Randomization is determined by a seed that you can change in the mod settings, so you don't have to worry about rebuilding your base each time because things were randomized differently.

  4. Active development New things are being added, for an even more randomized experience. See "Future Directions" below for more information!

Examples of things randomized...

  • Bot flying speeds
  • Bot charging speeds
  • The amount of energy a bot uses to fly
  • The amount of inventory slots for bots in a roboport
  • The amount of repair pack slots for bots in a roboport
  • The logistic connection distance of a roboport
  • The construction area of a roboport
  • The mining speed of pumpjacks/mining drills
  • The number of module slots that anything accepting modules can have
  • Module effects and their magnitudes
  • Pollution released by machines
  • The health of anything that has health
  • Ammo damage
  • Gun range
  • Inserter pickup/dropoff positions
  • Tech costs
  • Stack sizes
  • Cliff sizes
  • ...and more!


This mod doesn't randomize recipes. Try with Vill's randomizer for recipe randomization: https://mods.factorio.com/mod/ZRecipeRandomizer

Make sure to check the mod settings (Main Menu --> Settings --> Mod Settings, most are under the "Startup" tab) to customize your randomization experience.

Ctrl + Shift + E opens the "prototype explorer", which you can use to search the properties of things in factorio and to check if some things are better/worse than normal. Some modding experience might help here since it's hard to navigate.

Alternatively, try Extended Descriptions by NotNotMelon (https://mods.factorio.com/mod/extended-descriptions) for a more user friendly but less complete source of information.

Future Directions

This mod is being actively worked on and I'm planning exciting new features. Here are some of the things I have planned! The estimated time of completion for all these features is soon™.

  1. Complete Randomization Better recipe randomization, now with technology randomization and more added!
  2. Statistics Screen See how "lucky" you were in various areas and the normal values of things
  3. More Customization Specify blacklists/whitelists/all sorts of lists of the things you do or don't want randomized
  4. Preservation of Upgrade Lines Guarantees that Assembly Machine 2's will have some redeeming properties over Assembly Machine 1's instead of occasionally being just strictly worse, and so on for other upgrade lines.

Known Issues

  • Having very high/low bias and very high chaos factor can cause problems with certain seeds when things get too random. Use at your own risk.
  • Icon randomization seems to not be fully compatible with some mods.
  • Incompatible with expensive mode. (Note that expensive mode is being reworked in the upcoming version 2.0 anyways).
  • Info mods other than NotNotMelon's Extended Descriptions may report incorrect values.

Other Randomizers

I like to appreciate and draw attention to others in the community who contribute to the growing number of randomization mods, each with its unique niche. I highly recommend you try out these randomizers by other talented modders

AI's Science Shuffle, forked an maintained by Chembot, by Alrecenk and Chembot
* https://mods.factorio.com/mod/zChemsScienceShuffle
* Randomizes science pack ingredients like Science-Randomizer.

Archipelago Randomizer
- https://archipelago.gg/tutorial/Factorio/setup/en
- An inter-game randomization experience where milestones in one game give random unlocks in a different one.

Icon Randomizer, by RedRafe
- https://mods.factorio.com/mod/icon-randomizer
- Randomizes icons very similarly to the icon randomization setting in this mod. Doesn't go as far as BenCat's visual item randomizer, which also works with the item names. However, I think RedRafe's is more compatible with other mods with a few tests.

Keniras' Random Recipes, by Keniras
- https://mods.factorio.com/mod/zKenirasRandomRecipes
- Randomizes properties, the original inspiration for this mod. Also can randomize the ingredients/results of recipes by multiplying their amounts by a random number.

Random Factory Plus, by Kintharo
- https://mods.factorio.com/mod/RandomFactoryPlus
- Adds new content in a random manner.

Random Science, by MelonDude360
- https://mods.factorio.com/mod/Zrandomscience
- Procedurally generates new science packs.

Randomtorio, by CosmicWolf
- https://mods.factorio.com/mod/randomtorio
- Randomizes the recipe products, which actually has additional implications over just randomizing ingredients due to tech unlock orders. This is dual to the way vill's randomizes things, which is by just switching out ingredients.

Science-Randomizer, by redart
- https://mods.factorio.com/mod/science-randomizer
- Randomizes science pack costs. Doesn't have to deal with as much balancing due to implicit assumption that science packs aren't often used as intermediates.

Vill's Recipe Rnadomizer, by Villfuk
- https://mods.factorio.com/mod/ZRecipeRandomizer
- Randomizes recipes only, but does so in a very balanced way.

Visual Item Randomizer, by BenCat
- https://mods.factorio.com/mod/Item_Visuals_Randomizer
- Randomizes icons and other visual components where possible. Doesn't seem compatible with space exploration, and probably not with other overhauls either.


  • Villfuk02#6009 on discord for his PRG, which is used in this mod.
  • u/capslawl on reddit for the thumbnail.
  • u/Scuba-Cat- on reddit for the first image in the gallery.