They mean the same thing. While is standard everywhere and is the only form in general American use. Whilst is chiefly British, more formal, and sounds archaic to many readers — including many British ones. Neither is wrong; while is the safer default.
The core difference
Variants of one word, split by region and register rather than meaning.
- while — standard in all varieties; the only usual form in American English.
- whilst — chiefly British, formal, and increasingly dated.
The -st ending
Whilst belongs to a small group of English words that acquired a parasitic -st: amongst, amidst, unbeknownst. All are optional variants of shorter forms, all lean formal or archaic, and all are declining. If you avoid amongst, avoid whilst for the same reason.
A note on register
Writers sometimes reach for whilst to sound more careful. It tends to have the opposite effect on modern readers, reading as stiff rather than precise. While costs nothing and dates nothing.
Frequently asked questions
Is whilst incorrect?
No, it is a legitimate variant — chiefly British, more formal, and increasingly dated.
Do Americans use whilst?
Very rarely. While is standard in American English.
What other words have this pattern?
Amongst, amidst and unbeknownst all took a similar parasitic -st and all lean formal or archaic.