A cross-platform desktop app (macOS, Windows, Linux) for viewing, editing and comparing OOXML and
OpenDocument packages: .docx, .xlsx, .pptx and their macro/template variants (.docm,
.xlsm, .pptm, .dotx, .xltx, .potx, …) as well as .odt, .ods, .odp and the other ODF
formats.
Grab the build for your system from the latest release:
| Platform | File |
|---|---|
| macOS — Apple Silicon / Intel | OOXML-Toolkit-<version>-mac-arm64.dmg / …-mac-x64.dmg |
| Windows 10/11 (64-bit) | OOXML-Toolkit-<version>-win-x64-setup.exe (installer) or …-portable.exe |
| Linux (64-bit) | OOXML-Toolkit-<version>-linux-x86_64.AppImage |
The builds are not notarized yet, so each system asks for a one-time confirmation on first launch:
- macOS — open the app once (macOS blocks it), then go to System Settings → Privacy & Security
and click Open Anyway. On macOS 14 and earlier, right-click → Open works instead. In a terminal:
xattr -dr com.apple.quarantine "/Applications/OOXML Toolkit.app". - Windows — SmartScreen: More info → Run anyway.
- Linux —
chmod +xthe AppImage (and install FUSE 2 if it does not start).
Details are in the release notes. Prefer to build it yourself? See Getting started.
- A tree of the whole package on the left, details on the right — folders, parts and every XML element, or the relationship graph.
- Edit with confidence — change XML in the editor or the inspector; every edit is undoable, and saving only rewrites the parts you touched (everything else stays byte-for-byte identical).
- Compare two files, or your unsaved edits against the saved file, down to a side-by-side XML diff.
- Find things fast — text / regex / XPath search across all parts, go-to-part, bookmarks and recent files.
- Diagnose broken packages: malformed XML, dangling relationships, missing content types.
To run from source you need Node.js 24 (see .nvmrc; with nvm, nvm use) and npm.
npm install
npm run dev # start the Electron app with hot reload
npm run samples # optional: generate sample .docx/.xlsx/.pptx files in ./samples to play withOpen a file with File → Open (⌘O / Ctrl+O), drop it onto the window, or pass it on the command
line. See Development for installers and the other scripts.
The screenshots below were taken from the real app using the files in samples/
(npm run samples creates them). A complete reference lives in the user guide.
| 1 Tabs — open documents and comparisons (a dot means unsaved changes), Save (with Save As…) and Compare buttons | 6 Detail tabs — which ones appear depends on what is selected |
| 2 Activity bar — Explorer, Search, Bookmarks, Recent files, Package check | 7 Editor toolbar — validity, pretty-printing, format, wrap, find |
| 3 Tree mode (Parts / Relations), back / forward, collapse all | 8 Source editor, with the selected element highlighted |
| 4 The tree: folders → parts → XML elements | 9 XPath of the caret and Locate in tree |
| 5 Breadcrumb of the selection, bookmark / copy / export | 10 Status bar — type, part, size, caret, encoding, unsaved parts |
Open a file and click the root node of the tree. The overview shows how many parts the package has, the largest ones, the document properties and a one-click package check.
Expand folders and XML parts to drill down. Switch to Relations to follow the .rels graph the
way Office does — here from presentation.xml to its slides — and pick a slide to see it rendered.
Press ⇧⌘F / Ctrl+Shift+F, type what you are looking for, and click a hit: the part opens at the
match. Options for case, whole word and regular expressions sit inside the search box.
Switch to XPath for structural queries. Prefix x: addresses a default namespace — in a
worksheet, //x:c[x:f] finds every cell that contains a formula.
Select an element and open the Inspector: edit attribute values, add or remove attributes, edit
text, duplicate, move, delete or insert XML. Here the heading style Heading1 becomes Heading2.
The tab shows a dot, the status bar counts the unsaved parts, and ⌘Z / Ctrl+Z undoes it.
Prefer typing? The source editor is a full code editor with folding, find and syntax highlighting. Pretty re-indents minified XML for display only; the file changes only when you actually edit.
Slide order lives in presentation.xml. Right-click a p:sldId in the tree and choose Move Down.
On the overview (or via ⌥⌘D / Ctrl+Alt+D) choose Review changes to compare the saved file with
your edited version. Two lines swapped — and nothing else touched:
Saving (⌘S) then rewrites only presentation.xml; all other parts are copied unchanged.
Click Compare in the tab bar, pick the two files (open documents, recent files, or Browse…) and press Compare.
The tree lists every part with its status — Modified, Added, Removed, Formatting-only — and folder totals. Select a part to see the XML diff; switch between split and unified, step through changes with the arrows, ignore formatting or attribute order, and export a Markdown report.
Open the Package check (⇧⌘M / Ctrl+Shift+M). It reports malformed XML (with line and column),
relationships that point nowhere, parts without a content type and parts nothing refers to. Click a
problem to jump to it.
Worksheets, documents and slides have a Preview tab: a grid with a formula bar, a text outline, and positioned shapes, pictures and notes. Images get one too — including EMF and WMF metafiles, which are drawn as vector graphics (CAD and Visio exports, pasted Office charts).
⌘P/Ctrl+P— go to part: type a few letters of any part name.⌘D/Ctrl+D— bookmark the selected part or element. Bookmarks keep a name and a note and re-open their file when needed.- Recent files are kept (pin your favourites) and the previous session is restored on start.
.odt, .ods, .odp and the other ODF formats open like any other package. ODF has no relationships
or content types, so the app follows its own conventions instead:
- The overview reads
meta.xml— title, author, keywords, dates, editing time, slide / page / word counts and any custom properties. - Manifest (next to Parts in the explorer) lists every file in
META-INF/manifest.xmlwith its media type, flags entries that point at a missing file and collects files the manifest does not list. - Renaming or adding a part updates the manifest;
mimetypeis always saved first and uncompressed, as the format requires. - The package check verifies the
mimetypeentry and compares the manifest with the actual parts.
There are no slide, text or cell previews for ODF documents yet — you see (and edit) the XML.
Viewing — highlighted, foldable source; relationship tables (incoming and outgoing); image (PNG, SVG, EMF, WMF, …) and hex views; part info (content type, sizes, CRC-32, SHA-256, encoding); open embedded packages as their own document.
Editing — source editor, inspector, context-menu element operations; add, replace, export, rename
(relationships and content types are updated) and delete parts; undo/redo across everything;
atomic saves with an optional .bak; a warning before saving malformed XML; a warning (with a one-click
reload) when another program such as PowerPoint modifies a file that is open.
Comparing — two files or unsaved changes; part-level status with folder roll-ups and filters; split / unified diff; formatting-only differences detected; image comparison; Markdown report.
Productivity — search (text, regex, XPath), go-to-part, bookmarks, history, session restore, tabs, drag & drop, file associations, light / dark / system theme.
| macOS | Windows / Linux | |
|---|---|---|
| Open / Save / Save As | ⌘O / ⌘S / ⇧⌘S |
Ctrl+O / Ctrl+S / Ctrl+Shift+S |
| Go to part | ⌘P |
Ctrl+P |
| Search in package | ⇧⌘F |
Ctrl+Shift+F |
| Find in part | ⌘F |
Ctrl+F |
| Bookmark selection | ⌘D |
Ctrl+D |
| Compare files / review changes | ⇧⌘D / ⌥⌘D |
Ctrl+Shift+D / Ctrl+Alt+D |
| Package check | ⇧⌘M |
Ctrl+Shift+M |
| Back / Forward | ⌘[ / ⌘] |
Ctrl+[ / Ctrl+] |
| Undo / Redo | ⌘Z / ⇧⌘Z |
Ctrl+Z / Ctrl+Shift+Z |
| Toggle side bar | ⌘B |
Ctrl+B |
More in the user guide.
| Script | What it does |
|---|---|
npm run dev |
Electron app with hot reload |
npm run dev:web |
The same UI in a plain browser at http://localhost:5199 (no Electron; files via file picker / drag & drop) |
npm test |
Unit tests for the core library |
npm run typecheck |
Type-check main/preload and renderer |
npm run e2e |
Build, then drive the real Electron app with Playwright (open → edit → save → restore) |
npm run build |
Type-check and bundle into out/ |
npm run pack |
Unpacked app for the current platform in release/ |
npm run dist |
Installers / archives (dmg, zip, nsis, portable, AppImage) in release/ |
npm run samples |
Generate the sample documents in samples/ |
npm run screenshots |
Regenerate every screenshot in docs/screenshots |
npm run demo |
Re-record docs/demo.gif (needs ffmpeg) |
npm run icon |
Re-render build/icon.png from build/icon.svg |
Builds are unsigned by default. To sign and notarize on macOS remove identity: null from
electron-builder.yml and provide the usual CSC_* / APPLE_* environment variables; the CI workflow
in .github/workflows/ci.yml builds all three platforms.
src/
core/ Framework-free logic (also used by the tests)
zip/ ZIP reader/writer: lazy extraction, verbatim re-use of untouched entries
xml/ offset-preserving parser, whitespace-safe formatter, element edits as text splices
package/ PackageModel (overlay + undo history), OPC content types & relationships,
part classification, folder tree, package validation
compare/ part-level package diff
preview/ worksheet / document / slide extraction, EMF / WMF → SVG conversion
search.ts full-text search and fuzzy part matching
main/ Electron main process: window, native menu, file access with a path allow-list,
atomic writes, JSON storage for history / bookmarks / settings / session
preload/ contextBridge API (sandboxed renderer, no Node access)
shared/ Host API contract and the command registry (menu and shortcuts come from one list)
renderer/ React + zustand UI, CodeMirror 6 editors; runs in Electron or a plain browser
tests/ Vitest unit tests e2e/ Playwright-driven Electron tests, screenshots, demo
Key ideas:
- The original archive is never mutated. Edits live in a per-part overlay; saving writes a new archive that re-uses the original compressed bytes of every unchanged entry. An open → save with no edits reproduces identical entries.
- The XML parser keeps source offsets, so selecting a node highlights its exact range in the editor and element edits are precise splices — quoting, entities, namespace prefixes and attribute order survive untouched.
- One undo history per package, with snapshots per part; typing is coalesced into single steps.
- The renderer talks to a small
HostApi; Electron implements it with IPC, the browser build with file inputs, downloads andlocalStorage.
- Password-protected Office files are OLE compound files, not ZIP packages, and cannot be opened.
Legacy binary formats (
.doc,.xls,.ppt) and.xlsbcontent are not parsed. - The package check verifies structure, not schemas: it will not tell you that an element is invalid according to the ECMA-376 schemas.
- The slide preview is a simplified rendering (positions, text, pictures, tables); fonts, fills, charts and SmartArt are not drawn. The worksheet preview shows raw values without number formats.
- EMF / WMF previews are converted to SVG with emf-converter: the picture is sized to the drawn content rather than to the header frame, and text uses the fonts installed on your machine. Very large metafiles (hundreds of thousands of records) take a moment.
- OpenDocument files have no slide, document or worksheet preview yet (the XML, properties, manifest and package check work). Encrypted ODF entries are listed but cannot be read.
- ZIP64 archives can be read but are not written (archives must stay below 4 GiB / 65 535 entries).
Contributions are welcome — bug reports, ideas, documentation and code. Please read CONTRIBUTING.md before opening a pull request, and note that the project follows a Code of Conduct. Security issues should be reported privately as described in SECURITY.md.
MIT — see LICENSE.