In This Guide
You wrote in American English and now your client, school or readers want British English. Colour, organise, centre and travelling look like small changes, but doing them by hand across a long document is slow and easy to get wrong. Here is how to do it properly.
Quick Answer
Set your document's proofing language to English (UK) so your editor flags US spellings, then fix them. For long text, paste it into a US to UK converter such as the free Spellense US to UK converter to change the spelling in one go, and read through the result once.
In Microsoft Word
- Select the whole document with Ctrl+A (Cmd+A on Mac).
- Open the Review tab, click Language, then Set Proofing Language.
- Choose English (United Kingdom) and click OK.
- Use Review → Spelling & Grammar. US spellings now show as errors.
Word flags the differences but does not rewrite them for you, so you still accept each correction. Use Set As Default in the language dialog if you want new documents to start in British English.
In Google Docs
- Open the document and choose File → Language.
- Select English (UK).
- Run Tools → Spelling and grammar and review the suggestions.
In Canva and Other Web Editors
Web editors usually rely on your browser's dictionary. In Chrome, open Settings → Languages, add English (United Kingdom), and select it for spell check. Reload the editor and US spellings should show a red underline. If nothing is underlined, see Canva Spell Check Not Working? 7 Fixes.
The Main Rules: US vs UK Spelling
A handful of patterns cover most differences:
| Pattern | US | UK |
|---|---|---|
| -or / -our | color, favorite, neighbor | colour, favourite, neighbour |
| -ize / -ise | organize, realize | organise, realise |
| -yze / -yse | analyze | analyse |
| -er / -re | center, theater | centre, theatre |
| single / double L | traveling, canceled | travelling, cancelled |
| -ense / -ence | defense, license (noun) | defence, licence (noun) |
| -og / -ogue | catalog, dialog | catalogue, dialogue |
| Other | gray, tire, aluminum | grey, tyre, aluminium |
Watch-Outs Before You Convert
- Do not blindly find-and-replace. Replacing color with colour will also change code, file names, CSS, product names and quotations that must stay as they are.
- Exceptions exist. The verb license keeps an s in British English, a computer program keeps one m, and meter is still the measuring device while metre is the unit of length.
- Vocabulary is separate from spelling. Elevator and lift, apartment and flat, truck and lorry are word choices, not spelling rules.
- Pick -ise or -ize and stay consistent. Mixing them in one document looks careless.
- Proper nouns stay as written: Pearl Harbor, United States Department of Defense, and a brand called Color Run.
Convert Any Text in Seconds
- Open the US to UK converter.
- Paste your text in the input box with US to UK selected.
- Read the converted British version and the changes it made.
- Copy the result back into your document, then give it one quick read-through.
The converter runs in your browser, so your text is not uploaded. It works on text you paste, so for a formatted Word file copy the text across, or use the proofing-language method above to keep your formatting. Switch the direction toggle to convert UK spelling back to American.
Frequently Asked Questions (FAQ)
The most common questions are answered in the FAQ section below. If you also proofread designs or scanned documents, see how to find spelling mistakes in a scanned PDF.
Have a Text to Convert?
Paste American English into the free US to UK converter and get British spelling instantly. Switch direction any time to go from UK back to US.