Co-Author Documents with OnlyOffice: How-To

Updated 14 November 2026 · Standard formula, shown below

Yes, you can co-author documents with ONLYOFFICE. The editors include a real-time collaboration mode that lets multiple people work on the same document, spreadsheet, or presentation simultaneously, with changes syncing in seconds and a chat panel for quick discussion. This guide explains how to set up co-authoring, what features you get, and the common pitfalls to avoid.

What Co-Authoring in ONLYOFFICE Means

ONLYOFFICE is a suite of office applications (Document Editor, Spreadsheet Editor, Presentation Editor) that runs in a web browser or as a desktop app. Its co-authoring feature is not just a shared file: it is a live, synchronous editing session. When two or more people open the same document, each user sees the others’ cursors and selections in real time. Changes appear almost instantly, and the document is saved automatically to the server. This is different from older “track changes” workflows, where edits are reviewed later; co-authoring is simultaneous editing.

The feature works on documents stored in a cloud (like Nextcloud, ownCloud, or Seafile), in the ONLYOFFICE cloud, or on your own server using the ONLYOFFICE Docs (formerly Document Server) integration. For a small team, the free desktop editors can also connect to a cloud service that supports the ONLYOFFICE protocol.

How to Start a Co-Editing Session

The exact steps depend on where your document lives, but the general flow is the same:

Open the document in ONLYOFFICE (web or desktop).
Click the “Share” button (usually top-right) and add the email addresses of your collaborators.
Set permissions: choose “Full access” (can edit, comment, and share) or “Review” (can only suggest changes).
Send the invitation link or let them open the document from the shared folder.
When everyone is in, you’ll see their colored cursors and avatars. Start typing—changes appear live.

If you are using the desktop editor and want to co-author, you must open a file from a cloud connection (e.g., add your Nextcloud account) rather than a local file. Local files are not synced live.

Key Co-Authoring Features

Real-time cursor tracking: You see exactly where each collaborator is editing.
Version history: You can view and restore previous versions of the document, even after many edits.
Comments and mentions: Leave comments on specific text or cells, and use @mentions to notify someone.
Built-in chat: A side panel for quick messages during the session (available in web editors).
Track changes: For review workflows, you can switch to “Review” mode and accept/reject suggestions.
Locking: When you are editing a cell in a spreadsheet, that cell is locked for others, preventing conflicts.

Comparing Co-Authoring Modes: Fast vs Strict

ONLYOFFICE offers two co-editing modes, which you can choose from the File tab (or in the settings before starting):

Fast mode (default): All changes are saved automatically, and everyone sees them immediately. This is best for brainstorming and quick edits.
Strict mode: Changes are not applied until you press “Save”. This is similar to working offline and then merging. Use this when you want to review every change before it goes into the shared document.

If you are working on a complex spreadsheet with many formulas, strict mode can reduce confusion, but fast mode is fine for most text documents.

Common Problems and Solutions

Co-authoring usually works smoothly, but you may hit a few snags:

“File is locked” message: This usually means someone else has the file open in a non-collaborative editor (like Microsoft Word) or the server didn’t release the lock. Ask the person to close the file, or wait a few minutes. If it persists, check the server’s “lock” settings.
Changes not appearing: Ensure everyone is connected to the internet and that the file is saved to the cloud, not just locally. In the web editor, check the connection icon.
Version conflicts: If two people edit the same paragraph at the same time, ONLYOFFICE keeps both but may show a conflict. In fast mode, it usually merges automatically; in strict mode, you may need to resolve manually.
Missing chat: The chat panel is only available in the web version, not in the desktop app. Use an external messenger instead.
Slow performance: Very large documents (hundreds of pages) can lag. Try splitting the document or using the desktop app for better performance.

Cost and Setup Options

ONLYOFFICE has a free tier and a paid one. The free desktop editors are open-source and allow co-authoring if you connect them to a cloud service that supports the ONLYOFFICE integration (like Nextcloud). The web-based editors require a server component called ONLYOFFICE Docs, which is free for up to 20 connections (users) when you self-host. For more users or additional support, you need a paid license.

If you don’t want to manage your own server, you can use ONLYOFFICE’s hosted cloud service, which has a free plan with limited storage and paid plans for more space and users. For most small teams, the free self-hosted option is sufficient.

Alternatives to ONLYOFFICE Co-Authoring

If ONLYOFFICE doesn’t fit your needs, consider these popular alternatives:

Google Docs: The most widely used real-time editor, free with a Google account, but it requires you to store files in Google Drive.
Microsoft 365 (Word/Excel): Offers real-time co-authoring when files are stored in OneDrive or SharePoint. It’s a paid subscription.
Zoho Writer: A free online word processor with real-time collaboration and a clean interface.
Collabora Online: A LibreOffice-based suite that integrates with Nextcloud and offers similar co-authoring features.

ONLYOFFICE stands out for its strong compatibility with Microsoft Office formats (docx, xlsx, pptx) and its ability to be self-hosted, which is a big plus for privacy-conscious teams.

Frequently Asked Questions

Can I co-author a document with someone who uses Microsoft Word?
No. Co-authoring requires all participants to use ONLYOFFICE editors. However, you can save the document as a .docx file and share it with a Word user, but they won’t be able to edit simultaneously with you.

Does co-authoring work on the mobile app?
Yes, the ONLYOFFICE mobile apps (Android and iOS) support co-editing, but the interface is more limited. You can view and edit, but some features like chat are not available.

How do I see who made a specific change?
Open the version history (File > Version History) and select a version. You’ll see a list of changes with the author’s name and timestamp. You can also turn on “Track changes” to see edits inline.

Is there a limit to the number of people who can co-author?
Technically, the limit depends on your server capacity. The free self-hosted version supports up to 20 simultaneous connections. The cloud plans have higher limits, but practical performance degrades with very large groups.

Can I co-author a document offline?
No. Co-authoring requires an internet connection to sync changes. You can work offline on a local copy, but you won’t see others’ edits until you reconnect.

What happens if two people edit the same paragraph?
In fast mode, ONLYOFFICE attempts to merge changes, but if it can’t, it keeps both versions and may show a conflict for you to resolve. In strict mode, you’ll need to manually merge after saving.

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