Nextcloud is your own private cloud — think Google Drive, Dropbox or iCloud, except the files live on a server you control, there is no monthly per-user fee, and nobody scans your data. Once it is running, you reach it three ways: in a web browser, through the Windows desktop app, and through the Android app on your phone. This guide is a plain-English tour of all three, with the real focus on the part that confuses newcomers most: the sync options. For every option you will get what it actually does and, just as important, when you would choose it.
Nothing here assumes you have used Nextcloud before. If a section covers something you already know, use the “jump ahead” link at the top of it. This guide is about using Nextcloud — if you still need a server, start with How to Set Up Nextcloud on a Windows PC, then come back here.
What we’ll cover
- Nextcloud in your web browser — the basics
- The Windows desktop app — the three ways to sync
- Every desktop sync option, explained
- The Android app — browsing, offline files and auto upload
- Every Android auto-upload option, explained
- Which sync option should I use? (by scenario)
- All sync options at a glance
- Test that syncing actually works
- Troubleshooting
- Glossary
- Reference links
1 — Nextcloud in your web browser
The web interface is the “home base” that always works, on any device, with nothing installed. Open https://cloud.yourdomain.com (or the address your host gave you) and sign in. Even if you plan to live in the desktop and phone apps, it is worth knowing the web side, because a few things — sharing, restoring deleted files, seeing old versions — are easiest here.
Files
The Files app (the folder icon in the top bar) is the heart of Nextcloud. Drag files from your computer straight onto the page to upload them, use + New to make folders or documents, and click the star to mark favourites. Two things new users miss:
- Deleted files (bottom-left) is your recycle bin. Anything you delete lands here first and can be restored, so a mistake is recoverable for a while — how long depends on the server’s settings and free space.
- Versions. Open the three-dot menu next to a file → Versions to see and restore earlier saves. Edit a document, regret it, and you can roll back — no need to keep
report-final-v2-really-final.docxcopies.
Sharing
Click the share icon on any file or folder. You can share internally with another account on the same server, or create a public link that works for anyone — optionally with a password and an expiry date. Public links are read-only unless you grant edit permission, so people can view and download without touching your originals.
Photos, Calendar and Contacts
Nextcloud is more than files. Photos gives you a phone-style gallery of everything your phone backs up (see auto upload later). Calendar and Contacts replace Google Calendar/Contacts and sync to your phone and desktop using open standards (CalDAV/CardDAV). You do not have to use them, but they are there at no extra cost.
Accounts and admin
If you run the server, you have an admin account. Make a normal account for day-to-day use (avatar → Administration settings → Accounts) and keep admin for maintenance. On managed hosting you usually just have your one account, which is fine.
2 — The Windows desktop app: the three ways to sync
Already using the desktop app? Jump to every desktop sync option.
The Windows app puts a Nextcloud folder on your PC and keeps it in step with the server, the same way the OneDrive or Dropbox folder you may already know works. Install it from nextcloud.com/install (Desktop app → Windows), click Log in, enter your server address, and approve access in the browser window that opens — that step quietly creates a dedicated app password for this PC, which is why you never type your real password into the app.
During setup — and any time afterwards, per folder — you choose how the app syncs. There are three modes, and picking the right one is the whole game:
your Nextcloud server
|
+------------------------+------------------------+
| | |
Sync everything Choose what to sync Virtual files
(all files copied (only the folders you (everything shows,
to this PC) tick are copied) downloads on open)
Sync everything
What it does: downloads a full copy of everything in your Nextcloud to the PC, and keeps it that way. Every file is physically present and works offline.
Why you’d use it: a desktop PC with plenty of disk space where you want everything local — fast to open, available with no internet, and effectively a second copy of your data. The catch is space: if your Nextcloud holds 400 GB, this PC needs 400 GB free.
Choose what to sync (selective sync)
What it does: shows you the folder tree on the server and lets you tick only the folders you want copied to this PC. Unticked folders are simply not downloaded here.
Why you’d use it: you keep everything in Nextcloud but only need some of it on this particular machine — say, the Work folder on your laptop but not 200 GB of home video. It is the classic answer when a device does not have room for the whole library.
Virtual files (files on demand)
What it does: shows every file and folder in File Explorer, but they start as tiny placeholders that take almost no space. A file downloads automatically the moment you open it, then behaves normally. You can right-click and choose “Always keep on this device” to pin important files offline, or “Free up space” to turn a downloaded file back into a placeholder.
Why you’d use it: this is the best choice for most laptops, especially with a small SSD. You see your entire Nextcloud, browse it like a normal drive, and only the files you actually touch use space. It is the same idea as OneDrive’s “Files On-Demand.” The only trade-off: opening a file you have not downloaded needs an internet connection.
3 — Every desktop sync option, explained
Beyond the three modes, the desktop app has a handful of settings worth knowing. You reach them from the Nextcloud icon in the system tray → the gear/settings, or the Settings window.
| Option | What it does | When to use it |
|---|---|---|
| Local folder | Sets where the Nextcloud folder lives on your PC. | Point it at a bigger drive (e.g. D:\Nextcloud) if your C: is small. Set this at first setup — moving it later means re-syncing. |
| Add folder sync connection | Creates an additional sync pairing — a second server folder synced to a second local folder. | Advanced setups where you want, say, a shared team folder synced to a different place than your personal files. |
| Ask for confirmation before synchronizing folders larger than X MB | Prompts you before a big new folder floods onto your PC. | Leave it on. It stops a shared 50 GB folder someone adds you to from silently filling your disk. |
| Ask for confirmation before synchronizing external storages | Prompts before syncing storage that is mounted into Nextcloud from elsewhere (another drive, an S3 bucket, etc.). | Leave on if your server uses external storage; it avoids pulling down huge mounted volumes by accident. |
| Always keep on this device / Free up space | (Virtual files only.) Pins a file for offline use, or turns a downloaded file back into an online-only placeholder. | Pin the handful of files you need on a plane; free up space on large files you rarely open. |
| Limit bandwidth (Network settings) | Caps upload and/or download speed. | Throttle uploads so a big sync does not choke your video calls or your housemates’ internet. |
| Pause / resume sync | Temporarily stops syncing. | On a tethered/mobile connection where you do not want to burn data, or while copying in a large batch of files. |
| Launch on startup | Starts the app when Windows starts. | Leave on — otherwise nothing syncs until you remember to open the app. |
How desktop sync actually behaves (and conflicts)
Desktop sync is true two-way sync: change a file on the PC and it updates on the server; change it on the server (or another device) and it updates on the PC. Deletes flow too — delete locally and it deletes on the server (into the server’s Deleted files bin).
If the same file is changed in two places before they sync, Nextcloud does not silently pick a winner — it keeps both, saving one as a conflicted copy with the date in its name. Open both, keep the right one, delete the other. This is a feature, not a failure: nothing is lost.
4 — The Android app: browsing, offline files and auto upload
Already set up on your phone? Jump to every auto-upload option.
Install Nextcloud from the Play Store (or F-Droid), tap Log in, enter your server address, sign in and grant access. The phone app works a little differently from the desktop, and understanding that difference saves confusion.
On the desktop, a whole folder is mirrored two ways. On the phone, that is not the default. Instead the Android app does two separate jobs:
- Browse and fetch. You can see everything on the server and open any file; it downloads on demand. Mark a file or folder “Available offline” (three-dot menu) to keep a copy on the phone and have the app keep it current — useful for documents you need without signal.
- Auto upload. The phone’s main “sync” job: automatically send new photos and videos (or any folder) up to Nextcloud. This is one-way, phone → server, and it is what replaces Google Photos backup.
5 — Every Android auto-upload option, explained
Open the app menu → Auto upload. You enable it per folder on the phone (Camera, Screenshots, a WhatsApp folder, anything). For each folder you set the options below.
| Option | What it does | When to use it |
|---|---|---|
| Source folder | The folder on the phone to watch (e.g. DCIM/Camera). |
Add Camera for photos; add others (Screenshots, downloads) if you want those backed up too. |
| Remote folder | Where on Nextcloud the files land (e.g. /Photos/Camera). |
Keep phone photos in their own tidy folder so they show up in the Photos app. |
| Upload with — Wi-Fi only | Only upload on Wi-Fi, never mobile data. | Turn on if you have a limited data plan. This is the setting that saves your data allowance. |
| Upload with — only while charging | Only upload when plugged in. | Turn on to protect battery — big video backups run overnight while charging instead of draining you during the day. |
| Only on unmetered Wi-Fi | Skips Wi-Fi networks flagged as metered (e.g. a phone hotspot). | On if you sometimes tether through another metered connection. |
| When a file already exists | Whether to skip or rename if the name clashes on the server. | Leave on the default; it stops accidental overwrites. |
| Original file will be… Kept | Uploads a copy; the photo stays in your phone gallery untouched. | The safe default — recommended for almost everyone. Your gallery keeps working normally. |
| Original file will be… Moved to app folder | Moves the file into the app’s own folder after upload. | Niche; only if you deliberately want the files out of the normal gallery location. |
| Original file will be… Deleted | Deletes the local file after a successful upload. | To free phone storage — but only once you trust the backup and ideally have a second copy. This is the one option that can lose a photo if something is wrong. |
| Use subfolders (by date) | Sorts uploads into year/month folders automatically. |
On, if you like photos organised by date rather than one giant folder. |
| File naming | How uploaded files are named (original name, or with a timestamp). | Timestamps help avoid clashes and sort cleanly; original names are more familiar. |
A gotcha worth knowing: Android aggressively “optimises” battery, which can pause background uploads. If auto upload seems to stop when the screen is off, exempt Nextcloud from battery optimisation in Android’s Settings → Apps → Nextcloud → Battery (set to Unrestricted). Also note that files already queued keep the settings they had when queued — change a setting and it applies to new uploads.
6 — Which sync option should I use?
Match the option to the device and what you want from it:
| Your situation | Best option |
|---|---|
| Laptop with a small SSD, want to see everything | Desktop Virtual files, pin the few files you need offline |
| Desktop with plenty of space, want everything local and offline | Desktop Sync everything |
| Work PC that should only hold work files | Desktop Choose what to sync (tick just the work folder) |
| Back up phone photos automatically | Android Auto upload on the Camera folder, Wi-Fi + charging, original Kept |
| A phone document you need without signal | Mark it Available offline in the Android app |
| Phone almost full of photos already backed up | Auto upload with original Deleted — only after confirming the backup, ideally with a second copy |
7 — All sync options at a glance
| Option | Where | Direction | Uses local space | In one line |
|---|---|---|---|---|
| Sync everything | Desktop | Two-way | All of it | Full local copy of your cloud. |
| Choose what to sync | Desktop | Two-way | Only ticked folders | Copy just the folders you pick. |
| Virtual files | Desktop | Two-way | Only opened/pinned files | See everything; download on demand. |
| Available offline | Android | Two-way (that item) | That file/folder | Keep a chosen file current on the phone. |
| Auto upload | Android | One-way (up) | N/A (uploads) | Auto-back-up new photos/files to the server. |
| Browse & open | Android/Web | Download on demand | Temporary | Reach any file without keeping a copy. |
8 — Test that syncing actually works
Do not trust a green checkmark — confirm end to end:
- Desktop → server: drop a file in the Nextcloud folder on your PC, wait for the green tick, then refresh the web interface — it should appear.
- Server → desktop: upload a file on the web; it should appear in your PC’s Nextcloud folder within a minute.
- Virtual files: a file you have not opened should show an “online only” (cloud) icon and take almost no space; open it and the icon changes to a green check.
- Phone auto upload: take a photo, then check the remote folder on the web. With Wi-Fi-only on, connect to Wi-Fi first. It may take a few minutes.
- Phone offline: mark a file Available offline, turn on airplane mode, and confirm you can still open it.
9 — Troubleshooting
A desktop file will not sync / shows a warning. Check the app’s Activity tab for the reason. Usual causes: the file is open and locked by another program, the name contains a character the server rejects, or you are out of storage. Close the file or rename it and it clears.
You see a “conflicted copy” file. Not an error — the same file was edited in two places. Open both versions, keep the correct one, delete the other.
Virtual files will not open. Online-only files need an internet connection to download on first open. Offline, only files marked “Always keep on this device” are available. Reconnect, or pin the files before you go offline.
Android auto upload stopped. Almost always battery optimisation killing the background job — set Nextcloud to Unrestricted in the phone’s battery settings. Also confirm your Wi-Fi/charging conditions are actually met (Wi-Fi-only will wait for Wi-Fi).
“Insufficient storage” / uploads fail. Your account quota or the server disk is full. Check usage in Personal settings; on a self-hosted server, check free disk space.
A deleted file vanished everywhere. That is sync working as designed — but look in the server’s Deleted files bin, where it can usually be restored.
Glossary
Sync — keeping the same files in two or more places and making changes flow between them. Backup — a separate, safe copy you can restore from; sync is not a backup because deletions and bad edits copy across. Two-way sync — changes flow both directions (desktop app). One-way — changes flow one direction only (Android auto upload: phone → server). Selective sync — choosing which folders to copy to a device. Virtual files / files on demand — files appear but download only when opened. Available offline — a file kept on the phone and updated automatically. Auto upload — automatic upload of new phone files to the server. Conflicted copy — the extra file Nextcloud keeps when the same file changed in two places. Quota — the storage limit on your account. App password — a one-off password an app uses instead of your real password, revocable on its own. WebDAV — the standard protocol the apps use to read and write files on the server.
Reference links
- Nextcloud clients — desktop, Android and iOS downloads
- Nextcloud desktop client manual — sync connections and virtual files in depth
- Nextcloud user manual — files, sharing, versions and the mobile apps
- Nextcloud community forum — the fastest place to get a problem diagnosed
- How to Set Up Nextcloud on a Windows PC — if you still need a server
That is the whole picture: browse and manage on the web, mirror what you need on the desktop, and let your phone back itself up automatically. Pick the sync option that matches each device and Nextcloud quietly keeps everything where you want it — on storage you own.