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About this tool
Swap casual wording for formal equivalents and back again using 112 register pairs, with risky swaps kept optional.
Formal Informal Word Swapper rewrites a block of text between registers using 112 paired equivalents — phrasal verbs, everyday vocabulary, connectives, contractions, hedges and email openings. Eighty of the pairs are marked safe, meaning the swap holds in essentially any sentence; the other thirty-two depend on the sentence and are applied only if you ask for them, because 'about' should not become 'regarding' in 'about ten kilos'. Longer phrases are replaced before shorter ones and your original capitalisation is preserved, so 'Can't' becomes 'Cannot' rather than 'cannot'.
Open Formal Informal Word Swapper on AltFTool — it loads instantly in your browser.
Paste or type the text you're working with.
Choose how it should be transformed or analyzed.
Copy the finished text into your document or post.
Context-dependent pairs are separated from the safe ones and only applied when you switch them on.
Formal to informal is included, which is useful for cutting bureaucratic padding out of a draft.
You see each replacement with its category and any warning attached, rather than a silently rewritten block.
Register shows up mostly in four places: phrasal verbs (find out versus determine), contractions (can't versus cannot), hedges and intensifiers (a bit, really, kind of), and greetings. Sentence length and passive constructions matter too, but swapping those four categories moves a text further than anything else.
In academic papers, contracts and official letters, yes — write cannot, do not, it is. In business email and most web copy, contractions now read as natural rather than sloppy, so the rule is about the document type, not about English generally.
It is longer, not better. Style guides consistently advise against 'utilise' where 'use' works, because it adds syllables without adding meaning. This tool includes the pair but marks it as context-dependent with that warning attached.
No. It substitutes words and fixed phrases only. Real formality also comes from sentence structure and from what you choose to say, so read the output before sending it — a word-level swap cannot fix a sentence that is rude or unclear to begin with.