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: your file never leaves your device. There is no upload step, no account, and no server-side copy of your document. The editing engine runs inside your browser, so the file goes from your disk to your tab and back — nothing in between.
That single property drives most of the design decisions here: no sign-up flow, no cloud storage, no telemetry that could carry document contents, and an offline mode that keeps working when the network does not.
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 — which is also why there is no upsell, no "free tier" that expires, and no reason for the site to want your files.
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 AGPL-3.0 at github.com/ranuts/document. The license means any hosted modification has to publish its source too.
- 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.
- No sync and no collaboration. There is no server holding your document, which also means no real-time co-editing and no cross-device sync.
- 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.