There is no difference in meaning: anybody and anyone are interchangeable in every ordinary sentence. "Has anyone seen my keys?" and "Has anybody seen my keys?" say the same thing. Anyone is somewhat more common in writing, anybody a shade more conversational, and that is the whole of it.
Genuinely the same word twice
Both are indefinite pronouns meaning any person at all. They appear in the same places, take the same grammar, and can be swapped in either direction without changing sense. The same is true of the parallel sets: somebody/someone, everybody/everyone, nobody/no one.
What little difference exists is register and rhythm. Corpus evidence puts anyone ahead in edited writing; anybody is more at home in speech and informal prose. Neither is more correct, and no style guide treats one as an error.
How to choose
Read the sentence aloud and pick the one that scans better. Anybody has three syllables and adds weight; anyone is lighter and shorter. In a formal report, lean to anyone. In dialogue or a friendly email, either works.
- "Anyone wishing to attend should register by Friday." (formal)
- "Is there anybody down there?" (spoken)
The grammar both share
Both take a singular verb: "Anyone is welcome", not are. But both are routinely followed by they/their when the person's identity is unknown: "Has anyone lost their coat?" That combination is standard in modern English and has a long history in writing; "his or her" is heavier and no more correct.
The trap that actually matters
The real distinction is not between the two words above but between anyone and any one written as two words. Two words means any single member of a specified group, and the stress falls on one:
- "Any one of these keys will open the door." (any single key)
- "Anyone can open the door." (any person)
The test: if you can add of plus a group after it, or if you could substitute a single, use two words. The same applies to every one versus everyone, and some one is now almost always written closed.
Finally, both words are used with negatives and questions rather than plain positive statements — "I didn't see anyone", "did anybody call?" In a positive sentence, anyone shifts meaning to "it doesn't matter who": "anyone could have done it".
Frequently Asked Questions
Is anyone more formal than anybody?
Slightly. Anyone is more frequent in edited writing and anybody is more common in speech, but both are standard and neither will look out of place.
Should I write "anyone has" or "anyone have"?
"Anyone has" — both anyone and anybody are grammatically singular. "Has anyone seen it?" is correct; "have anyone seen it" is not.
What is the difference between anyone and any one?
Anyone means any person. Any one, as two words, means any single item or member of a group — "any one of the three routes". If you could say "a single", write two words.