Files never uploaded
Everything is processed on your device — no uploads, no content collection, no sensitive permissions.
Beijing Haichuan Youbang Technology Co., Ltd. Good tools,
Good tools,
for users everywhere.
One Office is a lightweight, privacy-first document toolkit built natively for Android, iOS and HarmonyOS — about 13 MB to install, with rich tools to preview, edit, convert and process PDFs entirely on your device. Files are never uploaded.
2018
Founded in Beijing
3 platforms
Android · iOS · HarmonyOS
Global
China + overseas release
Product
Open, edit and convert — in one app
One Office is light to install and never uploads your files, with a rich set of tools for preview, editing, format conversion and PDF processing — natively on Android, iOS and HarmonyOS.
Light and fast
About 13 MB on Google Play — a tiny install with rendering tuned for mobile, so large files stay smooth.
All-format preview
Open PDF, Word, Excel and PowerPoint directly — plus ODF, CSV/TSV and common text formats.
In-place editing
Rich text in DOCX, cells in XLSX, text boxes in PPTX and plain TXT — changes write back to the original file.
Format conversion
Convert Word/Excel/PPT to and from PDF, turn images into PDFs — one tap, saved locally.
PDF toolbox
Merge, split, extract pages, add or remove watermarks, encrypt and decrypt — the everyday tools are all here.
Download
Native on Android, iOS and HarmonyOS
Lightweight, no uploads, rich tools. Download the Android APK directly — all three platforms are built natively.
Download Files never uploaded Light install · about 13 MB Rich tools · preview / edit / convert / PDF
Going global
Built for the global market from day one
Utility apps are naturally global. One product serves many markets — released overseas and in China in parallel, so good tools stay within reach.
Dual-market release
Google Play for users worldwide, plus the leading stores in China — one product, two growth channels.
Multilingual products
The app ships in Simplified Chinese and English, the website is bilingual, and the architecture is ready for more languages.
A focused app portfolio
We concentrate on work and productivity tools — small, sharp apps that iterate fast and grow the global portfolio step by step.
About
A team focused on building good tools
Founded in 2018 and based in Beijing, HCYB Tech focuses on taking utility apps global. We put our energy into software engineering and product craft. Good tools should not need a manual.
About the company 01
Product driven
Getting every detail right matters more than a long feature list.
02
User perspective
Products start from real usage scenarios, not from technology.
03
Long term
Sustained R&D investment to build tools people keep using.
Want One Office to work even better?
New features, rough edges, or partnerships — tell us what would make it better for you.
Make a wishservice_hcyb@163.com