British β American Spelling
Convert colour/color, organise/organize, centre/center and more, both ways.
About this tool
Choose British β American or American β British, paste your text and the converted version appears straight away, with capital letters kept and every changed word listed. When converting to British English, words with two British spellings depending on meaning, such as check/cheque and program/programme, are flagged for you to decide rather than changed. Tick Oxford spelling to keep -ize endings. Nothing is stored.
British vs American spelling rules
Most differences follow a few patterns, many of them dating from Noah Webster's American dictionary of 1828. British -our becomes American -or (colour, color; favourite, favorite). British -ise/-yse becomes -ize/-yze (organise, organize; analyse, analyze). British -re becomes -er (centre, center; theatre, theater; metre, meter). -ogue becomes -og (catalogue, catalog; dialogue, dialog). -ence becomes -ense (defence, defense; licence, license). British English doubles the final l before a suffix (travelled, cancelled, jewellery), while American English usually doesn't. ae and oe simplify to e (anaemia, anemia; oestrogen, estrogen). Some words are one-offs: grey, gray; aluminium, aluminum; tyre, tire; cheque, check; plough, plow. Going from American to British is harder because some British words change spelling with meaning. A cheque is money but you check a list, a tyre is on a wheel but you tire when exhausted, and a programme is on TV but a computer runs a program. Practice is a noun and practise a verb. -ize isn't wrong in British English: Oxford spelling and many publishers use it. Honest limits: the tool changes spelling only, not vocabulary (lift, elevator; flat, apartment) or grammar, and its word list covers the common cases rather than every word. Find and replace and the case converter are related.
Frequently asked questions
Why do British and Americans spell words differently?
Mostly because of Noah Webster's spelling reforms in his 1828 American dictionary, which simplified spellings like colour to color.
Is -ize British or American?
Both. -ize is standard in American English and accepted in British English (Oxford spelling), though -ise is more common in the UK.
Does it change words like check and program?
Going to British English, those are flagged for you to decide, because the British spelling depends on meaning.
Is my text stored?
No. It's converted in your browser and never saved or sent.