American and British spelling, counted
Research
The English Wiktionary gives 364 pairs of English words in written use as American or British spellings of each other. The largest group is -ize / -ise (207 pairs).
The patterns
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).
Examples of each pattern
| Pattern | Pairs |
|---|---|
| -ize / -ise | organisation / organization, realise / realize, recognised / recognized, recognise / recognize, apologise / apologize, specialised / specialized |
| -or / -our | favorite / favourite, colour / color, honour / honor, behaviour / behavior, favour / favor, neighbourhood / neighborhood |
| other | grey / gray, dependant / dependent, focussing / focusing, jewelry / jewellery, ageing / aging, aluminum / aluminium |
| e / ae, oe | encyclopaedia / encyclopedia, haemorrhage / hemorrhage, ischaemic / ischemic, oestradiol / estradiol, maneuverability / manoeuvrability, haematoma / hematoma |
| one l / two | canceled / cancelled, modelling / modeling, enrolment / enrollment, labelled / labeled, councilor / councillor, instalment / installment |
| -er / -re | centre / center, manoeuvre / maneuver, spectre / specter, kilometer / kilometre, saber / sabre, millimeter / millimetre |
| -o- / -ou- | mould / mold, colter / coulter, smoldering / smouldering, molt / moult, molder / moulder |
| -ense / -ence | licence / license, offence / offense, pretence / pretense |
| -ter / -tre | centred / centered, centerpiece / centrepiece |
| -og / -ogue | catalog / catalogue, travelog / travelogue |
| -yze / -yse | analyse / analyze, paralyse / paralyze |
| -m / -mme | programme / program |
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).
The pairs people search most
| Pair | Google a month | Bing a month |
|---|---|---|
| canceled / cancelled | 201,000 | 0 |
| catalog / catalogue | 6,600 | 290 |
| dependant / dependent | 5,400 | 0 |
| licence / license | 1,300 | 190 |
| center / centre | 1,900 | 140 |
| traveler / traveller | 4,400 | 0 |
| recognise / recognize | 2,900 | 10 |
| jewellery / jewelry | 2,400 | 20 |
| program / programme | 1,300 | 70 |
| favorite / favourite | 1,600 | 50 |
| authorisation / authorization | 1,900 | 10 |
| saber / sabre | 1,000 | 20 |
| dike / dyke | 0 | 60 |
| cosy / cozy | 590 | 30 |
| humor / humour | 480 | 30 |
| moustache / mustache | 480 | 30 |
| neighbor / neighbour | 390 | 30 |
| rigor / rigour | 110 | 30 |
| minimise / minimize | 480 | 10 |
| honored / honoured | 320 | 10 |
| somber / sombre | 90 | 20 |
| wilfully / willfully | 0 | 20 |
| flavored / flavoured | 70 | 10 |
| councillor / councilor | 50 | 10 |
| capitalise / capitalize | 40 | 10 |
Sources: Google Ads keyword data through DataForSEO and Microsoft Advertising keyword data through DataForSEO, the average month from September 2025 to August 2026, United States.
Method and limits
A pair is counted when Wiktionary defines one word as the regional spelling of the other (“Commonwealth and Ireland standard spelling of color”, “US spelling of …”), both are single words in written use (Zipf 1 or more), they differ by at most three letters, and neither is an inflected form of the other. Patterns are matched on the letters that differ; “other” holds the pairs no pattern covers (grey and gray, aluminium and aluminum). Written frequency cannot separate American from British use (the corpus mixes both), so this page counts pairs, not usage by country.
How this was written
The text of this analysis was written with AI tools; its figures are queries on PlainSpell's database, and the text was checked against them. No figure is typed by hand. Editorial policy · Report an error.