BYTETOOLS

British to American Spelling Converter

Convert text between British and American spelling in both directions, with guarded rules, an Oxford -ize mode and a full list of every change made.

Paste some text above to convert it between British and American spelling, with every change listed and highlighted.

Rules are applied only where they are safe. “Advise”, “surprise”, “exercise” and about sixty other words keep their -ise; “size”, “prize” and “seize” keep their -ize; “laboratory”, “humorous” and “honorary” never gain a u; and “obliterate” is never turned into a -re word. A few pairs are converted one way only, because the reverse would be wrong — American “story”, “check”, “tire” and “curb” have meanings that British “storey”, “cheque”, “tyre” and “kerb” do not. Everything runs in your browser and nothing is uploaded.

What is the British to American Spelling Converter?

British to American Spelling Converter rewrites text in either direction using orthographic rules — -ise/-ize, -isation/-ization, -yse/-yze, -our/-or, -re/-er, doubled-l inflections, -ogue/-og and the ae/oe digraphs — each one guarded so it never over-applies.

  • Both directions, plus an Oxford spelling mode that keeps -ize
  • Rules for -ise, -yse, -our, -re, doubled l, -ogue and the ae/oe digraphs
  • Guarded by exception lists so advise, size, laboratory and obliterate are never touched
  • Around 250 hand-written irregular pairs and exceptions on top of the rules
  • One-way pairs marked with a note where the reverse would change the meaning
  • Every change listed with its count, the rule that made it and any warning

How to use the British to American Spelling Converter

  1. 1

    Paste your text into the box.

  2. 2

    Choose the target: American English, British English with -ise, or British English with Oxford -ize.

  3. 3

    Turn the -ogue shortening and the -t past tense conversion on or off.

  4. 4

    Read the converted text with every change highlighted, and check the change table for the rule and any caveat.

  5. 5

    Copy the result or download it as a .txt file.

About the British to American Spelling Converter

British to American Spelling Converter rewrites text in either direction using orthographic rules — -ise/-ize, -isation/-ization, -yse/-yze, -our/-or, -re/-er, doubled-l inflections, -ogue/-og and the ae/oe digraphs — each one guarded so it never over-applies. “Advise”, “surprise” and “exercise” keep their -ise; “size”, “prize” and “seize” keep their -ize; “laboratory”, “humorous” and “honorary” never gain a u.

On top of the rules sits a hand-written list of irregular pairs — tyre and tire, kerb and curb, aluminium and aluminum, programme and program — and a set of one-way pairs whose reverse would be wrong, because American “story”, “check” and “tire” mean things British “storey”, “cheque” and “tyre” do not.

There is an Oxford spelling mode that keeps -ize while converting everything else, every change is listed with the rule that produced it, and the whole conversion runs in your browser with nothing uploaded.

Frequently asked questions

What is Oxford spelling?

It is British spelling that uses -ize rather than -ise for verbs from the Greek -izein — organize, realize — while keeping everything else British, so it is still colour, centre and travelling. The Oxford English Dictionary and several academic publishers use it.

Why wasn't “advise” changed to “advize”?

Because the -ise in advise is not the Greek suffix — it is part of the root. About sixty words behave this way, including surprise, exercise, comprise, televise and promise, and they are all in the tool's exception list.

Why are some words converted in only one direction?

Because the reverse would be wrong. British “storey” becomes American “story”, but American “story” is usually a tale, not a floor. The same applies to cheque and check, tyre and tire, kerb and curb, and licence and license — those pairs are marked with a note.

Does it convert vocabulary as well as spelling?

Only where the difference is genuinely orthographic, such as aeroplane and airplane. It does not swap lift for elevator or boot for trunk — those are word choices that depend on the sentence and belong to a human editor.

Is British English -ise or -ize?

Both are correct British spellings. -ise is far commoner in general British use and is what most UK style guides specify; -ize is the Oxford convention and is standard in some academic publishing. Pick the mode that matches your house style.

Is my text uploaded?

No. Every rule and word list ships with the page and runs in your browser, so your text never leaves your device and the converter keeps working offline.

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