Can you put Infinity on a crossbow?
No. You can't put Infinity on a crossbow in Java 26.3, not even with an anvil.
Why not
Infinity is not on the crossbow's list. Here is what a crossbow can take instead: Curse of Vanishing, Piercing, Multishot, Quick Charge, Unbreaking, Mending.
What that means in practice
Infinity is a bow-only enchantment. A crossbow loads one arrow per shot instead, and Piercing arrows can be picked up again, which saves ammunition in a different way. Multishot also fires three arrows for the price of one.
What to use instead
Infinity is a bow-only enchantment. Crossbows use Multishot, Piercing and Quick Charge instead. Mending keeps the crossbow repaired. On a fresh crossbow, Multishot costs 2 levels and Piercing IV costs 4 levels as a book.
If arrows are your worry, a bow with Infinity is the answer. Otherwise, a Piercing crossbow loses very few arrows, because you can pick each one up again after the fight. Arrows are cheap anyway: one flint, one stick and one feather make four.
See Multishot and Piercing, or the full crossbow build.
Why the game says no
Infinity only goes on bow. A crossbow is not on that list. That matters because each enchantment's data file lists the items it supports, and the anvil checks that list. So the anvil gives no result, and the enchanting table never offers it.
No survival trick changes that. Combining two items, renaming or using a grindstone first all leave the list the same.
The best crossbow build instead
So a max crossbow has Multishot, Quick Charge III, Unbreaking III and Mending. In the cheapest order it costs 17 levels over 4 anvil steps, and no step goes above 6. Open it in the calculator.
The best crossbow enchantments page explains every book, and the crossbow enchant order shows each anvil step.
Where Infinity goes
- Infinity goes on bow. The enchanting table can offer it there directly.
Commands and creative mode
The /enchant command refuses too, because a crossbow can't support Infinity. Only /give with the enchantments component can attach it, which makes a command-only item that survival can never produce. The command generator writes the right syntax for your edition.
Java and Bedrock
As far as the item list goes, the answer is also the same in Java and Bedrock. The anvil differs, though: Java charges the full new level of every book. This page follows Java 26.3.
About Infinity
Infinity lets you shoot forever with a single normal arrow in your inventory. Special arrows are still used up.
Infinity has a max level of I. If you need a book, you can get it from the enchanting table, librarian villagers and enchanted loot from fishing and chests. A librarian sells an Infinity book for 5 to 19 emeralds. Before you buy, read everything about Infinity, including what each level does.
What else a crossbow can take
Instead, a crossbow can take Piercing, Multishot, Quick Charge, Unbreaking and Mending. Then the best crossbow enchantments page ranks them and gives the max build.
Related questions: Mending on crossbow, Multishot and Piercing on crossbow.
Questions
Can you put Infinity on a crossbow?
No. You can't put Infinity on a crossbow in Java 26.3, not even with an anvil.
What else can Infinity go on?
bow.
Is there an Infinity for crossbows?
No. Piercing comes closest: its arrows can always be picked up again.
Does Multishot use three arrows?
No. Multishot fires three arrows but only uses one from your inventory.
Can a crossbow have Mending?
Yes. Crossbows take Mending, and since they can't take Infinity, there is no conflict to worry about.
What is the best crossbow build?
Multishot, Quick Charge III, Unbreaking III and Mending. Swap Multishot for Piercing IV if you prefer collectable arrows.
Can a crossbow get Infinity from an enchanting table or a villager?
No. The enchanting table only offers enchantments an item supports. A villager's Infinity book still can't go on a crossbow, because the anvil checks the same list.