The past tense, and past participle of "split" is "split". I don't think that "splitted" is grammatical, though I dare say it gets used.
What is the meaning of the following sentence? You have successfully split a hair that did not need to be split. Source: this post on the Programmers Stack Exchange.
idioms - What does "You have successfully split a hair that did not ...
What should be used in below sentence: “split” or “split up”, and why? We need to split up the background image of the website into two parts.
When to use split and split up - English Language & Usage Stack Exchange
For the most part, the words are interchangeable. Distinguishing between multiple examples of such things can be aided by their individual connotations: crack a line on the surface of something along which it has split without breaking into separate parts A crack tends to be a visible flaw that can splinter or spider into larger cracks with many smaller, attached cracks. The defining point of ...
In the sentence I have a bibliography page which I'd like to split in/into sections which would you rather use: split in or split into? Why?
"Split in" vs "split into" - English Language & Usage Stack Exchange
Does the "in" imply multiplication, in which case split in half is correct, or is it division? It sounds like the latter to me, but I've heard it used both ways.
"Split in half" vs. "split in two" — which one is correct?
The problem with this is that unlike the runs or scissors or the heebie-jeebies or any other example I can think of, The Splits has multiple forms of use that necessitate a singular form. No one is ever concerned about having "a run" in regard to making it to the toilet. The Splits starts out sounding wrong but then quickly devolves into being un-useable when you have to describe a particular ...