Original
Changed
ignore case ignore trailing whitespace

## Compare two texts — or two Word documents

Paste the original on the left and the changed version on the right (or drop a file into each), then press Compare. Deleted lines are struck through in red ink, added lines are marked in green, and within a changed line the exact edited region is highlighted. Switch to the unified view for a classic patch-style reading, or copy it for a commit message or email.

Drop in a Word document and Proof Desk opens the Document view: the two files are laid out side by side with their formatting — headings, bold, lists, tables, and images, the way Draft Desk shows them — and the paragraphs that changed are tinted, added on the right in green and removed on the left in red. The Side-by-side and Unified views are still there for a line-level read.

## One comparison desk, growing a format at a time

Proof Desk started as a plain-text diff and is meant to keep learning formats. Today it reads plain text and code (.txt, .md, .csv, .json, .xml, source files) and Word documents (.docx — the text is pulled out with a hand-written ZIP + XML reader, the same machinery Draft Desk uses). Drop a .docx into either side and it compares as text. More formats (PDF, RTF, ODT) will land here rather than in a separate tool.

## Catch the gremlins hiding in your text

Flip on 🔍 Inspect and Proof Desk stops comparing and starts x-raying: it flags the characters that hide in pasted text and cause trouble — zero-width and other invisibles, bidirectional controls (the "Trojan Source" trick that makes code read one way and run another), no-break and other odd spaces, and homoglyphs (a Cyrillic "а" wearing a Latin "a"'s coat, the classic look-alike-domain phish). One button cleans a pane — stripping the invisibles and mapping look-alikes back to plain ASCII — while leaving your visible punctuation alone.

## Why this one is safe for private text

Most online diff tools send both texts to a server — a strange thing to do with contracts, unpublished writing, config files, or anything with names and secrets. This page has no server: the comparison runs as code in your browser tab, using a hand-written implementation of the same Myers algorithm Git uses. Save the page and it works with no internet connection at all.

## Honest limitations

- Comparison is line-based, with in-line highlighting for edited lines — it's about the words, not the formatting.
- For .docx, the Document view shows each file's formatting (headings, bold, lists, tables, images), but the comparison itself is by paragraph text — a paragraph counts as "changed" when its words change, not when only its formatting does.
- Old binary .doc (pre-2007) isn't supported — save as .docx first, or convert with File Mill.
- Extremely large or completely rewritten files fall back to a plain "everything changed" view rather than freezing your browser.
- Nothing is saved: reloading the page clears both panes.

Same shelf: Draft Desk edits the document once you've seen what changed · Sheet Desk does the same for spreadsheets · File Mill converts between document and data formats.

Part of K-Engine Local Tools — free, privacy-respecting utilities that run on your device. The diff engine, ZIP reader, and DOCX extractor are hand-written; view-source and you're reading them. MIT licensed, from the K-Engine workshop · download the source.