US / UK / Canada Spelling Converter

Most of them follow a handful of patterns. American spelling was simplified in the 1800s, largely thanks to Noah Webster's dictionary, while British spelling kept more of its French and Latin forms.

• -or and -our: color and colour, favorite and favourite, behavior and behaviour.
• -er and -re: center and centre, theater and theatre, fiber and fibre.
• -ize and -ise: organize and organise, realize and realise. Both are correct in Britain, though -ise is more common.
• -yze and -yse: analyze and analyse, paralyze and paralyse.
• Doubled L: traveled and travelled, canceling and cancelling, but fulfill and fulfil go the other way.
• -ense and -ence: defense and defence, offense and offence.
• -og and -ogue: catalog and catalogue, dialog and dialogue.
• ae and oe: pediatric and paediatric, estrogen and oestrogen.

Then there are one-offs that don't fit any pattern, like gray and grey, tire and tyre, aluminum and aluminium, and jewelry and jewellery.

A mix of both. Canadian English mostly keeps the British -our and -re endings (colour, centre, theatre), the doubled L (travelled), and words like cheque and catalogue. But it uses the American -ize and -yze endings (organize, analyze) and American spellings such as tire, curb, and program. That's why converting American text to Canadian changes fewer words than converting it to British.

Either is correct. Most British newspapers, websites, and government writing use -ise. Oxford University Press, and many academic and international organizations, use -ize. This is known as Oxford spelling, and it's otherwise British. Pick "UK English, Oxford" as the target to get Oxford spelling, or convert from UK to UK to switch an existing British text from one style to the other. Whichever you choose, use it consistently.

Because their spelling depends on what they mean, and a find-and-replace can't tell. In British English, practice is the noun and practise is the verb. A meter measures something but a metre is a length, a computer program stays a program while a TV programme doesn't, and a check you write is a cheque. These words are left as written and marked in orange, so you can click each one and choose.

No. Those are different words rather than different spellings, so changing them automatically would often go wrong. Instead, the converter lists the ones it finds, like sidewalk and pavement or zip code and postcode, so you can decide.

It's built on VarCon, an open-source list of American, British, Canadian, and Australian spellings maintained alongside the SCOWL spell-checking word lists and checked against Oxford and Merriam-Webster dictionaries. It covers more than 10,000 word forms, including plurals and verb endings, so colors, colored, and coloring are all converted, not just color.