The stack, and why Nextcloud alone isn't enough
Onyimadu describes Nextcloud as a very good file manager for storage, sharing, accounts and folder sync. It doesn't give him the full office editor he wanted. So he added ONLYOFFICE Docs and linked the two with a small connector app.
His reported versions are Nextcloud 35.0.1, ONLYOFFICE Docs 9.3.0 and connector 10.2.0. They run on Docker Desktop on his main computer. We could not independently confirm that exact three-version combination. The connector's public release notes do say that v10.2.0 is compatible with Nextcloud 35. Treat the rest of the version list as his claim.
He chose ONLYOFFICE because he handles DOCX and XLSX constantly. He notes that Nextcloud can also pair with Collabora Online. Nextcloud's own documentation confirms that Nextcloud Office is built on Collabora Online, which needs a dedicated service running next to the Nextcloud webserver stack. That is a different product with its own requirements. The article gives no evidence on whether Collabora and ONLYOFFICE behave the same.
The localhost trap
Starting the containers took minutes. Making them cooperate took longer. The connector needs two kinds of address:
- One the browser can reach.
- One the Nextcloud container can use to reach the ONLYOFFICE container.
He first typed localhost for both. That failed for the container-to-container link, because inside a container localhost points back at that same container, not at its neighbour.
ONLYOFFICE's integration documentation matches this model. Its Advanced server settings let you set an ONLYOFFICE Docs address for internal requests from the Nextcloud server, plus a returning Nextcloud address for internal requests from ONLYOFFICE Docs. The same documentation lists the matching config keys. DocumentServerUrl is the public address, DocumentServerInternalUrl is the internal address used for server-to-server communication, and StorageUrl is the internal Nextcloud address that ONLYOFFICE Docs uses.
Community threads show the usual fix. One ONLYOFFICE forum reply advises that if both run as containers, they should share a Docker network, and the connector's internal address fields should use the container name rather than an IP. The exact value depends on your container names and networks, so there is no universal URL to paste in. The same threads also show that fixing one direction doesn't guarantee the other. One user got Nextcloud reaching ONLYOFFICE by container name, but ONLYOFFICE's callback to Nextcloud still timed out.
A short checklist for the same setup
- Put both containers on the same user-defined Docker network.
- Keep the browser-facing address separate from the internal addresses.
- Fill in both internal-address fields in the connector, covering Nextcloud to ONLYOFFICE and ONLYOFFICE back to Nextcloud.
- Match the JWT secret on both sides. ONLYOFFICE says that since Docs v7.2, JWT is enabled by default, and the same secret must go in the connector settings.
- Read the 10.2.0 release notes. They say the
allow_local_addressconfig option is now required to check an ONLYOFFICE Docs address on the local network. If the address check fails on a LAN, look there first. This is my inference from the notes, not something the author reported.
What worked in daily use
The author says that clicking a DOCX in Files opens the editor in the browser, with no download and no "open with" prompt. Over about a week he edited drafts, built spreadsheets with charts and formulas, and made a slide for a talk. All of it opened from the same file list in a ribbon-style toolbar he compares to Microsoft's.
Files from other people held up well in his tests:
- Comments and tracked changes were visible.
- He could reply to comments and accept edits, then save back as DOCX.
- Conditional-formatting highlights on spreadsheets survived.
On the home network, two people could edit the same document at once. They could see each other's cursors and names, and sidebar comments appeared without a refresh. Away from home, he reaches Nextcloud over his Tailnet, so he doesn't expose the web interface to the public internet.
Where it hiccuped
Two problems stand out.
Fonts. A presentation used a font that wasn't installed on the ONLYOFFICE server. The title wrapped onto another line and rendered correctly only after he changed the font. The fix is simple: install the fonts your documents use on the server, or substitute them before sharing. He still opens each file one last time before sending it.
Offline editing. This was his one real loss. Google Docs in Chrome or Edge can keep working without a connection. His setup keeps no local browser copy to edit when Nextcloud is unreachable.
ONLYOFFICE's documentation also warns about format conversion. It says that some data might be lost when saving to formats such as csv, odp, ods, odt, rtf and txt. That is a good reason to keep DOCX, XLSX and PPTX as your working formats.
The part Google used to do for you
The article's most useful section is a comparison of who does which job:
| Job | With Google | On this setup |
|---|---|---|
| Updates | Happen in the background | Nextcloud, ONLYOFFICE Docs and the connector are updated separately |
| Backups | Google manages the service | He schedules copies of Nextcloud's data and database |
| Remote access | Google handles it | He maintains private access through his Tailnet |
| Availability | Managed for him | His computer and containers must be running |
He accepts this because he already maintains the rest of his self-hosted stack. He also acknowledges that many people would rather have the upkeep handled quietly for them.
Analysis: control isn't the same as safety
The appeal is real. You decide where your files live, and the browser workflow stays familiar. But the article offers no audit, benchmark or cost comparison. It would be a stretch to call this setup more private, more secure, cheaper or more reliable than Google Docs. The story doesn't mention backup frequency, restore testing, authentication settings, encryption at rest or protection of shared links. Don't assume any of those are covered just because the files sit on your own hardware.
Running the stack on a main desktop under Docker Desktop also ties the office suite's uptime to that PC. If the machine sleeps, reboots or loses its network, collaborators lose access. A dedicated always-on host would change that. That is general IT reasoning, not something the author tested.
Bottom line
This is a credible proof of concept for a self-hosted browser office. Nextcloud, ONLYOFFICE Docs and the connector can deliver a Google Docs-like experience for DOCX and XLSX work. Anyone copying it should:
- Check version compatibility.
- Get the two-address configuration right.
- Test representative files, including fonts, comments, tracked changes, formulas and slide layout.
- Plan backups and updates before trusting it with important work.
If you can accept no offline editing and the admin chores, it's a worthwhile weekend project. If you can't, Google's tab will stay open.