# GenOffice fork that works with any local LLM instead of a cloud account > Source: > Published: 2026-08-18 09:03:41+00:00 **A free, open-source AI Office suite — this fork drops the cloud-account requirement and talks to any OpenAI-compatible endpoint instead: a local server (Ollama, LM Studio, vLLM, llama.cpp server, text-generation-webui) or a hosted API (OpenRouter, or any other OpenAI-compatible provider).** Forked from [genspark-ai/genoffice](Apache-2.0). Changed per Apache-2.0 §4(b): the AI provider defaults (`packages/ai-provider/src/providers.ts` ) and settings UI (`apps/shell/src/renderer/src/SettingsModal.tsx` ) — see git history for the full diff. Everything else is upstream GenOffice, unmodified. [Demo](https://www.youtube.com/watch?v=B2pLdMX95v4) — upstream's video; the editor features it shows are unchanged in this fork, only the AI provider setup differs. GenOffice is a free, open-source alternative to Microsoft Office for macOS, Windows, and Linux, built around AI editing as a first-class workflow rather than a bolted-on chat box. It opens and saves the real Microsoft Office formats — Word (`.docx` ), Excel (`.xlsx` ), PowerPoint (`.pptx` ) — and edits PDF and Markdown too: a word processor, spreadsheet, presentation editor, PDF editor, and Markdown editor as six Electron apps sharing one engine layer. [Watch the demo video on YouTube](https://www.youtube.com/watch?v=B2pLdMX95v4) **Real PDF editing**— retype text and edit images in the page itself, original fonts preserved.** Microsoft Word–compatible, byte-preserving**— only what you touched changes; Word never notices.`.docx` editing**Word-faithful pagination**— page breaks land where Word puts them.** Excel-compatible spreadsheets**— in-house engine with a Rust`.xlsx` sidecar, own charts, pivot tables, slicers.**PowerPoint-compatible presentations**— in-house`.pptx` engine with masters, layouts, smart guides, non-destructive crop.**Markdown to Word, fully local**— the same OOXML engine, no Pandoc, no cloud.** AI that edits documents**— block-level edits with snapshots and diffs, document-aware agents.** Agent tools built in**— web/image search, image generation, media analysis.** Light / dark / system themes.****macOS, Windows, Linux.****Free & open-source (Apache-2.0).** This fork does not publish prebuilt installers — build from source (see [Development](#development) below: `npm install` , then `npm run dist:mac` / `dist:win` / `dist:linux` ). Upstream's own prebuilt installers, linked from [genspark-ai/genoffice](https://github.com/genspark-ai/genoffice), default to the Genspark cloud provider — they are not this fork. | App | Product | What it is | |---|---|---| `apps/docs` | GenOffice Docs | `.docx` word processor. Byte-preserving round trip: only dirty paragraphs are regenerated (paragraph patch), everything else in the original file is kept byte-for-byte, so opening and saving never breaks layout in Word. Paginated view whose line metrics reproduce the original document's layout, tracked changes, comments, styles, equations, ink. | `apps/sheets` | GenOffice Sheets | `.xlsx` spreadsheet. UI built on the open-source `.xlsx` import/export runs through an in-house Rust sidecar (calamine + IronCalc), charts are rendered in-house (Konva), plus pivot tables, slicers, conditional formatting, and formula tracing. | `apps/slides` | GenOffice Slides | `.pptx` presentations. In-house `.pptx` parse/render/edit engine with masters, charts, cropping, ink, and text shaping (HarfBuzz metrics). | `apps/pdf` | GenOffice PDF | `.pdf` viewer/editor on | `apps/markdown` | GenOffice Markdown | `.md` / `.markdown` editor: Tiptap block editor over plain Markdown files — headings, lists, tables, images, code blocks — saved back as plain Markdown, hosted in shell tabs. | `apps/shell` | GenOffice | The suite shell: home screen, tabbed hosting of the five editors, light/dark/system theme, auto-update. | Every app embeds the same AI panel: block-granular AI editing with version snapshots and diffs in docs, a tool-calling agent over workbook/slide/PDF state in the others. The whole suite ships light / dark / system UI themes built on shared design tokens (`packages/ui` ), with a CI guard that keeps chrome colors on the token system. Document surfaces stay light in dark mode — Word-style dark chrome around white paper — so files render and export identically in both themes. **AI backend.** On a fresh install this fork defaults to the **Local / Custom (OpenAI-compatible)** provider with the base URL, model, and key all blank — nothing is pre-configured, no account or cloud sign-in required. Point it at any server that speaks the OpenAI `chat/completions` wire protocol: | Server | Base URL | Model | API key | |---|---|---|---| | `http://localhost:11434/v1` `llama3.1` [LM Studio](https://lmstudio.ai/)`http://localhost:1234/v1` [OpenRouter](https://openrouter.ai/)`https://openrouter.ai/api/v1` `openai/gpt-4o-mini` Settings → AI Provider → Local / Custom (OpenAI-compatible), fill in the three fields, then Test connection. Upstream's other providers are still selectable in the same screen and work as upstream describes: **Genspark** signs in via a device-code flow (no key needed) and also unlocks the Genspark ("gsk") tool endpoints the agents build on — web/image search, image generation and editing, media analysis, audio transcription (`packages/ai-search` ); **Claude / Gemini / DeepSeek / OpenAI** need that vendor's own API key. All pure TypeScript, no Electron dependency, unit-tested (except the UI kit): `packages/docx-engine` — docx parsing → block tree (with`docxIndex` anchors and passthrough), OOXML fragment generation, byte-level paragraph patching.`packages/pptx-engine` /`packages/pptx-render` — pptx model and rendering.`packages/file-parse` — text extraction for AI attachments (office formats, text formats).`packages/agent-core` — the AI agent loop and skill composition shared by every app.`packages/ai-provider` — provider abstraction and streaming for the model backends.`packages/ai-search` — Genspark auth + web/image search tools.`packages/i18n` ,`packages/ui` ,`packages/project-store` ,`packages/electron-utils` — shared i18n core, React UI kit, recent-files store, and Electron main-process helpers. ``` npm install npm run fixtures # generate test .docx fixtures npm test # engine + app unit tests (docs/sheets/slides need no display) npm run typecheck # tsc --noEmit across every workspace npm run dev # all five editors + shell against Vite dev servers npm run dev:docs # a single app (same pattern works per workspace) npm run dist:mac # package macOS dmg (regenerates third-party notices) npm run dist:win # package Windows nsis installer npm run dist:linux # package Linux AppImage + deb + rpm ``` The sheets app additionally needs a Rust toolchain for its xlsx sidecar (`cargo` on PATH); `npm run build -w @genoffice/sheets` compiles it automatically. Local UI/e2e driver scripts (Playwright + Electron, for local acceptance, not committed by default) live in [ scripts/drivers/](/douglas168/open-genoffice/blob/main/scripts/drivers/README.md). ``` open docx ─► archive original by hash (never touched) ─► docx-engine parses word/document.xml top-level elements (w:p / w:tbl / …) ─► Block tree, each block anchored by docxIndex + original XML slice ─► Tiptap streaming editor (manual + AI editing, dirty tracking) save ─► dirty blocks → OOXML fragments (referencing existing styles only) ─► splice into original document.xml (untouched blocks keep original bytes) ─► repack zip; all other entries copied byte-for-byte ``` The same philosophy holds in sheets and slides: the original file is the source of truth, edits are applied as narrow patches, and everything the editor didn't touch survives the round trip untouched. **Is GenOffice free?** Yes. GenOffice is free and open-source under the Apache-2.0 license — no trial, no paid tier for the apps themselves. **Can GenOffice open Microsoft Word, Excel, and PowerPoint files?** Yes. GenOffice opens and saves native `.docx` , `.xlsx` , and `.pptx` files. Saving is byte-preserving: parts of the file you didn't touch are written back byte-for-byte, so documents keep working in Microsoft Office. **Does GenOffice work offline?** Document editing is fully local — files never leave your machine to be opened, edited, or saved. The AI features need a network connection to whatever endpoint you configure in Settings → AI Provider — a LAN-only local server (e.g. Ollama) keeps that traffic off the public internet too; a cloud provider (Genspark, OpenRouter, a named vendor) does not. **Can GenOffice edit PDF files?** Yes — real PDF text and image editing that rewrites the page content stream with the original fonts preserved, not cover-up annotations. See [SECURITY.md](/douglas168/open-genoffice/blob/main/SECURITY.md) for the process security posture (renderer sandboxing, IPC validation, external-link gating) and the threat models for AI-generated content. GenOffice would not be possible without these open-source projects: [Electron](https://www.electronjs.org/)— the desktop runtime for every app.[Univer](https://github.com/dream-num/univer)(Apache-2.0) — the spreadsheet UI core that Sheets extends.[PDFium](https://pdfium.googlesource.com/pdfium/)(BSD-3-Clause, bundled via[@embedpdf/pdfium](https://github.com/embedpdf/embed-pdf-viewer)) — the content-stream engine behind true PDF text and image editing.[pdf.js](https://github.com/mozilla/pdf.js)(Apache-2.0) and[pdf-lib](https://github.com/Hopding/pdf-lib)(MIT) — PDF rendering and document assembly.[Tiptap](https://tiptap.dev/)/[ProseMirror](https://prosemirror.net/)— the block editors in Docs and Markdown.[Konva](https://konvajs.org/)— canvas rendering for Slides and Sheets charts.[HarfBuzz](https://github.com/harfbuzz/harfbuzz)(wasm) — text-shaping metrics for complex scripts.[calamine](https://github.com/tafia/calamine)and[IronCalc](https://github.com/ironcalc/IronCalc)— the read and calc layers of the Rust xlsx sidecar.- Liberation, Carlito, Caladea, and Noto CJK fonts (OFL/Apache-2.0) — bundled document fonts. `npm run notices` regenerates the bundled third-party license summary (`tools/gen-third-party-notices.mjs` ); all runtime dependencies are MIT/Apache-2.0/BSD-3-Clause/OFL, and the bundled fonts (Liberation, Carlito, Caladea, Noto CJK subsets) are OFL/Apache. GenOffice is licensed under the [Apache License 2.0](/douglas168/open-genoffice/blob/main/LICENSE), with one exception: the `ee/` directory is reserved for future enterprise modules and is covered by the [GenOffice Enterprise License](/douglas168/open-genoffice/blob/main/ee/LICENSE). The GenOffice and Genspark names and logos are trademarks of Mainfunc, Inc. The Apache-2.0 license does not grant permission to use them (see section 6); forks should use their own branding.