British and American English- Spelling

Here are the principal differences in spelling between English and American English.
English American English
Final -l is always doubled after one vowel in stressed and unstressed syllables in English but usually only in stressed syllables in American English, for example: rebel > rebelled
travel > travelled rebel > rebelled
travel > traveled
Some words end in -tre in English and -ter in American English, for example: centre
theatre center
theater
Some words end in -ogue in English and -og in American English, for example: analogue
catalogue analog
catalog
Some words end in -our in English and -or in American English, for example: colour
labour color
labor
Some verbs end in -ize or -ise in English but only in -ize in American English, for example: realise, realize
harmonise, harmonize realize
harmonize
Common Differences
English American English
all right all right, alright (disputed)
analyse analyze
centre center
cheque check
colour color
counsellor counselor
criticise, criticize criticize
defence defense
doughnut donut
favour favor
fibre fiber
flavour flavor
fulfil fulfill
grey gray
honour honor
humour humor
jewellery jewellery, jewelry
judgement, judgment judgment
kerb curb
labour labor
license, licence (verb)
licence (noun) license (verb)
license (noun)
litre liter
metre meter
mould mold
neighbour neighbor
offence offense
practise (verb)
practice (noun) practice (verb)
practice (noun)
pretence pretense
programme program
pyjamas pajamas
realise, realize realize
savour savor
speciality specialty
theatre theater
travelled
travelling travelled, traveled
travelling, traveling
tyre tire
valour valor