Sentence Rewriter — Free Offline Synonym Tool

Click any word to swap in a synonym, or rewrite a whole paragraph at once. A private, offline thesaurus — your text never leaves your browser.

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What it does

Paste a sentence or paragraph and this tool highlights every word it has synonyms for. Click a highlighted word to pick a replacement from a small menu, or hit “Rewrite all” to swap every eligible word at once. It’s a lighter-weight, fully private alternative to sending your text to an AI paraphrasing tool — nothing you type is ever sent anywhere.

How it works

The tool uses a curated, built-in synonym dictionary covering several hundred common English words — common enough that it works entirely offline, instantly, with no loading delay for a CDN library. When you paste text, it’s split into words and everything-else (punctuation, spaces, numbers) so that reconstructing the sentence around a swapped word is always exact — your original spacing and punctuation are never disturbed.

Case is preserved intelligently: swapping a word at the start of a capitalized sentence keeps the capital, and an ALL CAPS word stays ALL CAPS. Simple plurals are handled too — swapping “problems” gives you a pluralized synonym like “issues,” not the singular “issue.” You can lock a word after picking a synonym so a later “Rewrite all” shuffle leaves your manual choice alone.

How to use it

1. Paste or type your text into the box.
2. Click any highlighted word to open its synonym menu and pick a replacement — or choose “(original)” to keep it as-is.
3. Use Rewrite all to swap every eligible word at once; click it again to reshuffle.
4. Lock any word you want to keep from a future shuffle, from the same menu.
5. Turn on diff view to see the original word struck through next to each replacement.
6. Copy the result or download it as a .txt file.

Limitations

This is a curated dictionary of common English words, not an exhaustive thesaurus — it won’t have synonyms for every technical term, proper noun, or rare word, and non-English text passes through untouched. Words are only ever swapped one-for-one; the tool doesn’t restructure sentences or change grammar.

FAQ

Does this send my text to a server or an AI model?

No — the entire synonym dictionary is built into the page and loaded once. There’s no network request involved in rewriting your text.

Why didn’t a word I expected to have synonyms get highlighted?

The dictionary covers common English vocabulary rather than every word. If a word isn’t highlighted, it simply isn’t in the built-in list yet — it passes through unchanged.

Will it mess up my capitalization or punctuation?

No — capitalization is detected and re-applied to whatever synonym you choose, and punctuation and spacing are preserved exactly since only the word itself is replaced.

Can I undo a change?

Yes — click the word again and choose “(original)” to revert it, or use “Reset to original” to undo every change at once.

What does “Lock this choice” do?

It protects that specific word from being changed the next time you click “Rewrite all,” so your manual picks survive a full reshuffle of everything else.

Does it handle plurals correctly?

For regular plurals, yes — a word like “problems” swaps to a pluralized synonym like “issues” rather than leaving you with a grammatically odd singular.

If you’re checking a draft for repeated wording before rewriting it, the Duplicate Word Finder will flag words you’ve used more than once, and the word/character counter is handy for keeping the rewritten version within a length limit.