Collabora Online vs OnlyOffice: Which Office Suite?
Quick Verdict
OnlyOffice has the better UI — it looks and feels like Microsoft Office, which matters for user adoption. Collabora has better document format fidelity — it’s LibreOffice under the hood, so complex .docx and .xlsx files render more accurately. For most self-hosted Nextcloud setups, OnlyOffice is the better default. For environments where document format accuracy is critical (legal, publishing, government), Collabora wins.
Overview
Both are self-hosted office suites that integrate with Nextcloud for collaborative document editing. They compete directly for the same use case: “I want Google Docs-style editing on my own server.”
Collabora Online (CODE) uses the LibreOffice engine. It processes documents server-side, with the browser acting as a thin client. Developed by Collabora, a commercial Linux consulting company that contributes heavily to LibreOffice.
OnlyOffice (Document Server) uses its own rendering engine optimized for OOXML formats (.docx, .xlsx, .pptx). It runs as a Node.js application and renders documents client-side in the browser using JavaScript.
Feature Comparison
| Feature | Collabora Online | OnlyOffice |
|---|---|---|
| Document editing | Full (Writer) | Full |
| Spreadsheet editing | Full (Calc) | Full |
| Presentation editing | Full (Impress) | Full |
| Document fidelity | Excellent (LibreOffice engine) | Good (optimized for OOXML) |
| .doc / .odt handling | Excellent | Good |
| .docx handling | Very good | Excellent |
| Macro support | LibreOffice macros (partial) | VBA-compatible macros |
| UI style | Ribbon-like (different from MS Office) | Very similar to MS Office |
| Mobile editing | Browser-based | Browser-based + mobile apps |
| Collaborative editing | Real-time (server-side) | Real-time (client-side) |
| Track changes | Yes | Yes |
| Comments | Yes | Yes |
| PDF export | Yes | Yes |
| Draw / Diagram editor | No | Built-in |
| Form builder | Limited | Built-in (fillable forms) |
| Nextcloud integration | Via Nextcloud Office app | Via OnlyOffice connector app |
Architecture and Resources
This is where the practical difference matters most for self-hosters:
| Metric | Collabora Online | OnlyOffice |
|---|---|---|
| Engine | LibreOffice Core (C++) | Custom OOXML engine (C++/JS) |
| Rendering | Server-side | Client-side (browser) |
| Docker image | collabora/code | onlyoffice/documentserver |
| RAM (idle) | ~1.3 GB | ~500 MB |
| RAM (per user) | ~100 MB | ~50-100 MB |
| CPU | Lower per-user (rendering is server-side) | Lower server-side (rendering is client-side) |
| Containers | 1 | 1 |
| Setup complexity | Medium (aliasgroup config + reverse proxy) | Lower (simpler env vars) |
| WebSocket requirement | Yes (mandatory) | Yes (mandatory) |
The key difference: Collabora’s 1.3 GB baseline RAM is the main drawback for small servers. It preloads the LibreOffice engine into shared memory on startup. OnlyOffice starts at ~500 MB, making it more viable on 2-4 GB VPS instances.
Document Format Fidelity
Collabora wins on legacy and ODF format handling because it is LibreOffice. A .doc file from 2005 or a complex .odt with embedded objects renders correctly. LibreOffice’s format support is 20+ years mature.
OnlyOffice wins on modern .docx handling because its engine was built specifically for OOXML. If your workflow is entirely Microsoft Office formats (which, realistically, most businesses are), OnlyOffice renders them more faithfully.
In practice: if you exchange documents with Microsoft Office users and formatting fidelity in .docx is critical, OnlyOffice is the safer choice. If you need to handle diverse formats including legacy documents, Collabora is more reliable.
User Experience
OnlyOffice feels immediately familiar to anyone who uses Microsoft Office. The toolbar layout, keyboard shortcuts, and editing behavior closely mirror Word, Excel, and PowerPoint. This dramatically reduces training time when deploying to teams.
Collabora’s interface is functional but visually distinct from both Microsoft Office and Google Docs. Users transitioning from either will need an adjustment period. The editing experience is solid, but it doesn’t have the polished feel of OnlyOffice.
Use Cases
Choose Collabora Online If…
- Document format fidelity across all formats (including .odt, .doc, legacy) is critical
- You work in government, legal, or publishing where exact rendering matters
- You’re already invested in the LibreOffice ecosystem
- You have 4+ GB RAM available on your server
Choose OnlyOffice If…
- You want users to feel at home coming from Microsoft Office
- Modern .docx/.xlsx/.pptx format fidelity is the priority
- RAM is constrained (2-4 GB servers)
- You want the simpler Docker setup
- You need built-in form creation or diagram editing
Final Verdict
For most self-hosted Nextcloud deployments, OnlyOffice is the better default. The lower RAM footprint, simpler setup, Microsoft Office-like UI, and excellent OOXML format support make it the practical choice. Collabora is the right choice when document format diversity or legacy format support is a hard requirement — and when your server has the RAM to spare.
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