ONLYOFFICE Docs

Last reviewed Sep 13, 2026 · 781 words

ONLYOFFICE Docs wants about 4 GB of RAM to be comfortable, and the free Community Edition stops at 20 simultaneous editing connections. Those two numbers decide whether it belongs in your stack before any discussion of features. Inside those limits, it is the self-hosted editor that round-trips Word, Excel and PowerPoint files most cleanly, and that fidelity, not the collaboration, is the reason to run it instead of the lighter alternatives.

It is an editing engine, not a place to keep files

Docs does not store documents and has no file browser of its own. It is a server that renders and edits a file some other application hands it. In a self-hosted stack that other application is almost always Nextcloud, Seafile or ownCloud, each of which has a connector that handles authentication and storage while Docs handles the editor. ONLYOFFICE's own Workspace and DocSpace products bundle a file layer, but for most people they are the wrong shape: you already have file sync, you want editing added to it.

The compose that works, and the secret that must match

services:
  onlyoffice:
    image: onlyoffice/documentserver:latest
    ports:
      - "8080:80"
    environment:
      - JWT_ENABLED=true
      - JWT_SECRET=a-long-random-string-you-generated
    volumes:
      - ./oo/data:/var/www/onlyoffice/Data
      - ./oo/logs:/var/log/onlyoffice
      - ./oo/db:/var/lib/postgresql
    restart: unless-stopped

The image bundles its own PostgreSQL and RabbitMQ, which is most of why it is heavy and also why it is one container rather than 3. The JWT_SECRET goes into the Nextcloud connector settings verbatim; a mismatch produces an unhelpful "document could not be saved" rather than an auth error, and it is the number one support question. Put the server behind your reverse proxy with a real certificate, because the browser loads the editor directly from the Docs server while the file itself is fetched by the Docs server from Nextcloud: both directions have to be HTTPS or the browser blocks the frame as mixed content. If both services sit on the same private network, Nextcloud's allow_local_remote_servers setting has to be true or it refuses to call a private address.

Fidelity is why you pick it over Collabora

The other serious option is Collabora Online, which is LibreOffice's engine served over the web. Collabora stores and thinks in ODF and converts Microsoft formats on the way in and out. ONLYOFFICE uses OOXML as its internal model, so a DOCX with tracked changes, comments, nested tables and a pivot table comes back out looking like it went in. If your documents live and die inside your own team, either is fine. If they are exchanged with people on Microsoft 365, ONLYOFFICE produces noticeably fewer "why did my formatting move" emails. The interface is also a deliberate copy of the ribbon-and-tabs Office layout, which matters for users who do not want to learn anything new.

What the 20-connection limit actually means

A connection is an open editor tab, not a user, and the counter is per Docs server. A household or a 10-person team never approaches it. A 30-person office with people leaving spreadsheets open all day hits it by Tuesday, and the failure mode is a polite refusal to open the 21st document. The Enterprise Edition removes the cap for a per-server fee that is reasonable for a business and absurd for a homelab. If you are near the line, that is the moment to reconsider Collabora, which has no equivalent hard limit in its free build, or CryptPad if end-to-end encryption matters more than Word fidelity.

Fonts and the first-open delay

Two smaller things. Custom fonts go into /usr/share/fonts/truetype/custom inside the container, followed by running /usr/bin/documentserver-generate-allfonts.sh; without that step, corporate templates render in a substitute font and users report it as corruption. And the first document opened after a restart takes several seconds while the editor bundle warms up, so check it yourself before a colleague does.

What I'd do

Give it a dedicated 4 GB VM or a host with that much headroom, deploy the compose above with a generated JWT_SECRET, put it behind Caddy on its own hostname, and connect it to Nextcloud. Then open one real DOCX from your archive and one XLSX with formulas before announcing it to anyone. For a team under 20 concurrent editors that exchanges files with the Microsoft world, it is the best Google Docs replacement you can run yourself. For a solo user who mostly writes Markdown, it is 4 GB of RAM you will regret.