They mean the same, but allt can also be used to mean all of... for uncountable ett-words.
"Alla" means "Everyone".
"Allt" means "Everything".
Alternatively, when used with a noun, "All/Allt/Alla" change according to the gender of the noun. The same way adjectives do.
Can someone get me a Shia LaBeouf meme with this sentence? Allt är möjligt om du försöker. gor de bara! (my alt command for umlaut o isn't working and gor doesn't show up in my swedish spellcheck). Also, would it be "gor de bara!" or "bara gor de!" or something else?
Both works, though it's "det". They're pronounced the same but spelled differently; your sentence translates to "Just do they!"
Wouls it be possible to say 'varjeting' to mean everything? Also, what is the difference between 'sak' and 'ting'
Nope, that doesn't work. :) They're synonymous, but ting is old-fashioned if not borderline archaic on its own.