[Guide] Factorio item GUI ordering
Posted: Mon Jul 06, 2026 8:33 pm
As far as I didn't find any usefull (understandable) help or article about how ordering in Factorio GUI working - I decide to close this gap for new young modders.
Here the already existing doc or post:
- https://lua-api.factorio.com/latest/types/Order.html
- viewtopic.php?p=23818#p23818
But I will provide some pictures and hopes this will be more usefull to understand, then just abstract text:)
The general structure of GUI ordering system is:
1) Item group
2) Item subgroup
3) Item order string
4) Item name
So, to find a place where your new item would be placed in GUI, first of all you need to understand a core source of base Factorio items\recipes:
https://github.com/wube/factorio-data
Here you can find basic descriptions of all items and recipes in the game.
You are interesting in several files:
- base/prototypes/item-groups.lua
- base/prototypes/fluid.lua
- base/prototypes/recipe.lua
- space-age/prototypes/item-groups.lua
- space-age/prototypes/fluid.lua
- space-age/prototypes/recipe.lua
According to names - they are split between base game and Space Age DLC.
Let's dive into code and try to understand how al this works
1. Group (aka, Logistics, Production, etc) - this is a tabs, you can see on the right side, when pressing E.
Here is how describing tabs look like in code:
Keep eyes on order field - there's key field, which define ordering. It's just a string and all ordering based on alphabetical sorting.
2. Subgroups (aka Storage, Belt) - this is how items orders inside each tabs. In each tab ordering starts from the begining.
Here is how it look in code:
3. Item order string - this is most confusing thing, which you maybe already saw in item description - order = "a-b-c', etc
This string describes how item ordered inside subgroups. In the past devs used more hard way with just "a-b-c", but now it moved to more understandable format - "a[storage]-b[wooden-chest]". So the text in [] used just for describing section inside subgroup.
Here ho it look in code:
Again, keep eyes on subgroup and order fields
Here the good example to understand the whole concept - we have subgroup Storage. And this subgroup divided into two internal groups - a[items] and b[fluids].
a[items] contains 3 items - wooden-chest, iron-chest, steel-chest. b[fluids] contains just 1 item - storage-tank.
Also, each chests has their own defined position - a[wooden-chest], b[iron-chest], c[steel-chest].
(The text insidde [] - does nothing, except more readable view). storage-tank also has dedicated position a[storage-tank] - which is the first position in b[fluids].
And finally, as far as 'a' comes before 'b' in EN aplphabet - the GUI will know how to order this items. First a[items], then b[fluids]. And inside a[items] will be clear that first will be a - wooden-chest, then b - iron-chest and then c - steel-chest.
So, for example, to add some new storage tank type - you can write a code like this:
4. Item name - GUI will use the item\recipe name, if you will omit some of ordering path definitions. I think this part is simple enough:)
To summarize - if you want to place you new modded items in the dedicated place in GUI items' list - you need to find closest already existed items, look at their subgroup and order string, and produce your own based on this info.
That's it:)
Hopes this will helps to understand how this system works:)
Here the already existing doc or post:
- https://lua-api.factorio.com/latest/types/Order.html
- viewtopic.php?p=23818#p23818
But I will provide some pictures and hopes this will be more usefull to understand, then just abstract text:)
The general structure of GUI ordering system is:
1) Item group
2) Item subgroup
3) Item order string
4) Item name
So, to find a place where your new item would be placed in GUI, first of all you need to understand a core source of base Factorio items\recipes:
https://github.com/wube/factorio-data
Here you can find basic descriptions of all items and recipes in the game.
You are interesting in several files:
- base/prototypes/item-groups.lua
- base/prototypes/fluid.lua
- base/prototypes/recipe.lua
- space-age/prototypes/item-groups.lua
- space-age/prototypes/fluid.lua
- space-age/prototypes/recipe.lua
According to names - they are split between base game and Space Age DLC.
Let's dive into code and try to understand how al this works
1. Group (aka, Logistics, Production, etc) - this is a tabs, you can see on the right side, when pressing E.
- 07-06-2026, 22-37-36.png (32.81 KiB) Viewed 128 times
Code: Select all
{
type = "item-group",
name = "logistics",
order = "a",
icon = "__base__/graphics/item-group/logistics.png",
icon_size = 128,
},
{
type = "item-group",
name = "production",
order = "b",
icon = "__base__/graphics/item-group/production.png",
icon_size = 128,
}
2. Subgroups (aka Storage, Belt) - this is how items orders inside each tabs. In each tab ordering starts from the begining.
- 07-06-2026, 22-51-15.png (50.72 KiB) Viewed 128 times
Code: Select all
{
type = "item-subgroup",
name = "storage",
group = "logistics",
order = "a"
},
{
type = "item-subgroup",
name = "belt",
group = "logistics",
order = "b"
},
{
type = "item-subgroup",
name = "inserter",
group = "logistics",
order = "c"
}
This string describes how item ordered inside subgroups. In the past devs used more hard way with just "a-b-c", but now it moved to more understandable format - "a[storage]-b[wooden-chest]". So the text in [] used just for describing section inside subgroup.
- 07-06-2026, 22-58-22.png (37.87 KiB) Viewed 128 times
Code: Select all
{
type = "item",
name = "wooden-chest",
icon = "__base__/graphics/icons/wooden-chest.png",
subgroup = "storage",
order = "a[items]-a[wooden-chest]",
inventory_move_sound = item_sounds.wood_inventory_move,
pick_sound = item_sounds.wood_inventory_pickup,
drop_sound = item_sounds.wood_inventory_move,
place_result = "wooden-chest",
stack_size = 50
},
{
type = "item",
name = "iron-chest",
icon = "__base__/graphics/icons/iron-chest.png",
subgroup = "storage",
order = "a[items]-b[iron-chest]",
inventory_move_sound = item_sounds.metal_chest_inventory_move,
pick_sound = item_sounds.metal_chest_inventory_pickup,
drop_sound = item_sounds.metal_chest_inventory_move,
place_result = "iron-chest",
stack_size = 50,
random_tint_color = item_tints.iron_rust
},
{
type = "item",
name = "steel-chest",
icon = "__base__/graphics/icons/steel-chest.png",
subgroup = "storage",
order = "a[items]-c[steel-chest]",
inventory_move_sound = item_sounds.metal_chest_inventory_move,
pick_sound = item_sounds.metal_chest_inventory_pickup,
drop_sound = item_sounds.metal_chest_inventory_move,
place_result = "steel-chest",
stack_size = 50
},
{
type = "item",
name = "storage-tank",
icon = "__base__/graphics/icons/storage-tank.png",
subgroup = "storage",
order = "b[fluid]-a[storage-tank]",
inventory_move_sound = item_sounds.metal_large_inventory_move,
pick_sound = item_sounds.metal_large_inventory_pickup,
drop_sound = item_sounds.metal_large_inventory_move,
place_result = "storage-tank",
stack_size = 50
}
Here the good example to understand the whole concept - we have subgroup Storage. And this subgroup divided into two internal groups - a[items] and b[fluids].
a[items] contains 3 items - wooden-chest, iron-chest, steel-chest. b[fluids] contains just 1 item - storage-tank.
Also, each chests has their own defined position - a[wooden-chest], b[iron-chest], c[steel-chest].
(The text insidde [] - does nothing, except more readable view). storage-tank also has dedicated position a[storage-tank] - which is the first position in b[fluids].
And finally, as far as 'a' comes before 'b' in EN aplphabet - the GUI will know how to order this items. First a[items], then b[fluids]. And inside a[items] will be clear that first will be a - wooden-chest, then b - iron-chest and then c - steel-chest.
So, for example, to add some new storage tank type - you can write a code like this:
Code: Select all
{
type = "item",
name = "storage-tank-mk2",
icon = "__base__/graphics/icons/storage-tank-mk2.png",
subgroup = "storage",
order = "b[fluid]-b[storage-tank-mk2]",
inventory_move_sound = item_sounds.metal_large_inventory_move,
pick_sound = item_sounds.metal_large_inventory_pickup,
drop_sound = item_sounds.metal_large_inventory_move,
place_result = "storage-tank",
stack_size = 50
}
To summarize - if you want to place you new modded items in the dedicated place in GUI items' list - you need to find closest already existed items, look at their subgroup and order string, and produce your own based on this info.
That's it:)
Hopes this will helps to understand how this system works:)