When people write aswell vs as well, they're usually just working from instinct about how the phrase sounds in speech. Spoken quickly, the two words blur into a single unit. On the page, though, only one form is correct: as well, always written as two separate words.
Why "aswell" is wrong
English does merge some two-word phrases into single words over time. Think of "everyone," "already," or "however." But that process isn't random. It follows patterns of frequency, grammatical role, and historical use. "As well" hasn't followed that path. No standard dictionary recognises "aswell" as a word, and no major style guide accepts it.
The error is driven by the way the phrase sounds in connected speech. When you say "I'll come as well," the two words run together almost seamlessly, and the brain files them as a chunk. Writers then reproduce that spoken chunk on the page. It's the same mechanism behind errors like infact vs in fact, where a common phrase gets compressed into a single misspelled unit.
What "as well" actually means
"As well" functions as an adverbial phrase. It means "also," "in addition," or "too," and it typically sits at the end of a clause. It can also mean "to an equal degree" in comparative constructions, though this use is less common in everyday writing.
- In addition: "She brought her sister as well."
- Also / too: "I'd like a coffee, and a glass of water as well."
- To an equal degree: "You might as well try."
All three uses require the two-word form. There is no context in standard English where "aswell" is the right choice.
Quick examples of correct use
"As well" works like "also" but carries a slightly more formal tone. You can place it at the end of a sentence, or use it in the fixed phrase "might as well" or "just as well." The phrase "might as well" means there's no strong reason not to do something. "Just as well" means it's fortunate something happened or didn't happen.
Here are clear examples of correct use:
"He speaks French and Italian as well."
"You might as well stay for dinner."
"It's just as well you checked."
And here are the same sentences with the error:
"He speaks French and Italian aswell."
"You might aswell stay for dinner."
"It's just aswell you checked."
Every version with "aswell" is wrong. The spell-checker in most word processors will flag it, but not all do, which is why the error still slips through in emails, reports, and social media posts.
How to remember the rule
The fastest fix is to treat "as well" the same way you treat "as much," "as soon," or "as often." None of those get merged into a single word, and neither does "as well." If you wouldn't write "asmuch" or "assoon," don't write "aswell."
Another reliable check: if you can replace "as well" with "too" or "also," the phrase is correct. If your replacement also sounds wrong, you probably have a different error entirely. Spacing errors like this one are a close cousin of other compound-word confusion, such as the question of standalone vs stand alone, where the correct form depends on grammatical role rather than sound.
Is "aswell" ever acceptable?
No. There's no regional dialect, informal register, or style guide that endorses "aswell" as a single word. It's purely a spelling error, not a variant. Unlike genuinely contested word pairs in English, this one has a clear, unambiguous answer.
Some writers worry that the correction might one day shift, given how freely English absorbs compound forms. That may be true of other phrases, but "as well" has resisted merger for centuries. It's not close to changing.
The quick summary
"Aswell" is always wrong. "As well" is always two words. Write it the way you'd write "as much" or "as soon," and you won't go wrong. Once you see the rule, it stays fixed.