Text Diff Checker — Compare Two Texts Word by Word
Quick answer
This text diff checker compares two texts at word level: paste an original and a revision, and the exact changed words highlight inline in seconds — ideal for prose, contracts, essays and documentation. It runs entirely in your browser, is free with no signup, and never uploads your text anywhere.
Last updated: October 16, 2026
Line-based diff tools treat text like code, and that is exactly wrong for writing: change one word in a sentence and the whole line floods red. This checker has a word mode built for prose — the changed words highlight inline, unchanged text stays quiet, and you read the revision as a natural edit instead of a rewrite. Contracts, essays, press releases, documentation and AI-revised paragraphs are its home ground; line mode is still one click away for structured text.
Use the tool below| 1 | function greet(name) { | 1 | function greet(name: string): string { |
| 2 | var message = "Hello, " + name + "!"; | 2 | const message = `Hello, ${name}!`; |
| 3 | console.log(message); | 3 | console.log(message); |
| 4 | return message; | 4 | return message; |
| 5 | } | 5 | } |
| 6 | 6 | ||
| 7 | // TODO: add farewell | 7 | function farewell(name: string): string { |
| 8 | greet("CodeLive"); | 8 | return `Goodbye, ${name}.`; |
| 9 | } | ||
| 10 | |||
| 11 | greet("CodeLive Studio"); | ||
| 12 | farewell("CodeLive Studio"); |
Text Diff Checker runs entirely in your browser — nothing you paste or type is uploaded to any server, and no account is needed.
How do I compare two texts word by word?
- 1
Press Words in the view selector (next to the editors) to switch the comparison from lines to words.
- 2
Paste the original text into the left editor and the revised text into the right — the inline diff appears immediately.
- 3
Read the merged result: inserted words glow green, deleted words glow red with a strike-through, and untouched text stays plain.
- 4
Refine with Ignore case or Ignore whitespace when formatting noise does not matter, and edit either side live to re-check instantly.
Word-level comparison done right
Inline word highlighting
The merged view shows one text with edits marked in place — green for insertions, red struck-through for deletions. Reading a revision becomes reading a sentence with two colored words in it, not scanning two full-text columns for differences.
Built for prose, contracts and essays
Punctuation-aware tokenization splits on words and spaces, so sentences, paragraphs and long lines all diff cleanly. It is the right granularity for documents where a single swapped word changes the meaning.
Line mode stays one click away
The same tool still compares line by line with aligned side-by-side rows and unified patch output — switch over for code, configs or logs without changing pages. Both modes share the same exact computation.
Live re-checking while you edit
Tweak a phrase on either side and the highlights update instantly. That turns the tool into an editing aid, not just a checker — try a rewording on the right, see exactly what it touched, undo it just as fast.
Your documents never leave the tab
Drafts, NDAs, academic work and personal text are compared in your browser with no upload path whatsoever. Server-based diff sites necessarily receive both documents; this architecture makes that impossible.
Free, no account, auto-saved
No signup stands between you and the comparison, and both texts persist locally between visits — a scratchpad for revisions that lives on your device, not in someone's cloud.
Why word-level diffing matters for writing
Writing revisions are surgical: a swapped adjective, a softened qualifier, a corrected figure. Line-based diffs exaggerate those edits into full-line replacements, which makes them exhausting to review and easy to skim past — the reader's eye gives up on walls of red and green. Word-level diffing keeps the signal-to-noise ratio honest: two words highlighted in a paragraph is an edit a reviewer can actually evaluate in place.
It is also the honest lens for machine-assisted text. Paste your draft and an AI's rewrite, switch to words, and the tool shows precisely which words the rewrite touched — catching both improvements and silent meaning changes. Writers use it the same way editors do: not to judge the text, but to see the delta without squinting.
Accuracy you can quote
The comparison uses the Myers algorithm — the same family behind git — applied at word granularity. That means results are minimal and deterministic: the highlights show a shortest edit script between your two texts, not a heuristic guess. Deterministic output also means re-running the same comparison always produces the same highlights, which matters when you are describing an edit to someone else.
The ignore-case and ignore-whitespace toggles map to real editorial questions — "did anything change besides capitalization?" — and the tool answers them directly instead of making you filter noise by eye. Combined with live re-checking, the loop of revise-compare-revise takes seconds per iteration.
Questions this tool answers
- text diff checker
- compare two texts word by word
- word diff online
- document diff checker free
- compare paragraphs online
Frequently asked questions
How is this different from a code diff checker?
Granularity and defaults. This page centers the word-level merged view that prose needs; the code diff checker leads with line-level side-by-side and patch export that code review needs. Both tools offer both modes — the difference is which one is in front of you.
Is my text uploaded to a server?
No — comparison happens in your browser tab and nothing is transmitted. For contracts, unpublished writing and personal documents that is the whole point: the tool works exactly as well with the network disconnected after load.
Can it handle long documents?
Yes — articles and chapters of several thousand words compare comfortably. For very long documents the word-level result is one long merged paragraph, so most people diff section by section; line mode handles whole documents at once.
Does it highlight punctuation changes?
Yes — punctuation attaches to words during tokenization, so a moved comma or changed quotation mark appears as part of the highlighted word. It catches the small mechanical edits that human eyes reliably miss.
Can I compare text with different formatting (bold, fonts)?
The tool compares plain text — paste from anywhere and formatting is stripped automatically. That is usually what you want when checking wording; visual formatting belongs to the document editor, not the diff.
Is it free to use?
Completely — word mode, line mode, options and live editing are all free with no account and no limits. The computation is local, so there is no usage cost to meter or monetize.
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