What this is
An in-browser editor for office documents. You open a Word (DOCX), Excel (XLSX), PowerPoint (PPTX), CSV or PDF file and edit it directly in a browser tab.
The part that matters most for the local path: your file never leaves your device. There is no upload step for local editing, and the editing engine runs inside your browser.
You can also keep a durable library in this browser (IndexedDB) without an account, or optionally subscribe to cloud storage so the same workbook follows your account across devices ($5/year · 1 GB or $10 · 10 GB). Cloud is opt-in; local editing stays free.
Who builds it
This site is built and maintained by ranuts, the same author behind the ranuts GitHub account and the ran component/utility libraries.
It is a personal open-source project, not a company product. There is no sales team and no venture funding behind it — optional cloud storage is priced to cover hosting, not to gate the local editor.
How you can verify all of this
Claims about privacy are cheap. These are the ways to check them yourself:
- Read the source. The whole thing is open source under MIT at github.com/ranuts/document. Application code is MIT; the embedded ONLYOFFICE editors remain AGPL-3.0 — see NOTICE.
- Watch the network tab. Open your browser's developer tools, load a document, edit it, and look at the network requests. You will not see your file being sent anywhere.
- Turn off the network. Load the site once, go offline, then open and edit a file. It keeps working, which is only possible because the editing happens locally.
- Self-host it. The repository includes what you need to run your own copy.
What it is built on
The editing engine is based on ONLYOFFICE, compiled to run in the browser. This project wraps that engine with a local-first shell: file handling, format conversion, the offline layer, embedding support, and the interface you see.
Being built on an existing engine is deliberate. Document formats — especially DOCX and XLSX — are large, messy specifications, and a from-scratch implementation would render your files subtly wrong. Reusing a mature engine means what you see in the browser matches what you would see elsewhere.
Limits worth knowing
An honest list, because a page that only lists strengths is not useful:
- Large files are bound by your device. Everything runs in your browser, so a very large spreadsheet is limited by your own memory and CPU, not by a server you can pay to upgrade.
- Collaboration is not built-in. Optional cloud storage syncs your own files across devices; it is not real-time co-editing.
- Fidelity is very good, not perfect. Complex layouts, unusual fonts and macros can differ from a desktop suite.
If any of these matter more to you than keeping the file local, a hosted suite is the better tool — and that is a reasonable choice.
Getting in touch
Bug reports, format problems and feature requests are best filed as issues on GitHub, where they stay public and traceable. See Contact for the ways to reach the project.