Syncthing Conflict Files What Sync Conflict Copies Mean and How to Clear Them
You open a folder and find a stranger next to your document: the same name, with "sync-conflict" and a date inside it. Nothing is broken — Syncthing just refused to choose a winner for you. Here is how to read, resolve and prevent these files.
✍️ Technical Anshu🖥️ Windows / Linux / Android⏱️ A 10 minute clean up, then prevention
🎥 The main Syncthing video shows normal sync running — this guide covers the day two edits collide
A conflict file appears when the same file is changed in two places while the devices are apart, and then they meet. Your laptop edited the report on a train; your office PC edited it at the same hour. Neither version is “the newer one” in any honest sense — they are two different futures of the same file. Syncthing will not silently destroy one of them. It keeps the version it judges primary, and saves the other beside it with a name like Report.sync-conflict-20251024-153012-ABCDEFG.docx. That file is not an error. It is a question, addressed to you.
A conflict in the wild — one file, two futures (example names)
Office Files folder, after laptop and PC edited offline:
Project Report.docx
Project Report.sync-conflict-20251024-153012-PBIKQTO.docx
│ │
│ └── device ID of the
│ copy that "lost"
└── date and time of the conflict
The plain file .......... the version Syncthing kept live
The conflict file ....... the other edit, preserved whole
Nothing was deleted. A human must merge or choose.
Illustrative panel — conflict names follow this documented pattern
1
Why Conflicts Happen — the Real Causes
Almost every conflict traces back to one of these:
Two editors, one file, no connection between them. The classic: a document edited on the laptop during travel and on the office PC the same day.
A device that was off for days wakes up holding an old edit, while the world moved on. Syncthing sees two changed versions with no clean ancestry.
Applications that rewrite whole files on save — some office and accounting programs touch the file even for a look, which counts as a change on that device.
Clock and filesystem oddities are rare causes; genuine simultaneous editing explains nine conflicts out of ten.
2
Resolving a Conflict Without Losing Work
Stay calm and treat it as a two-minute merge, not a disaster:
Open both files. The plain-named one is live; the conflict copy holds the other edit. Read both — the difference is usually one paragraph, one table or one section.
Merge by hand into the live file. Copy across whatever the conflict copy has that the live file lacks. For documents, your office suite's compare feature helps, but eyeballs are fine for small files.
Save the live file and let it sync. Once the merged version is saved on one device, it propagates everywhere as the single truth.
Delete the conflict file. Its deletion also syncs, and the folder is clean. Do this only after the merge — the conflict file is the only place that other edit exists.
If the conflict copy turns out to be the better version wholesale, close the apps, rename it over the live file on one device, and let that sync instead. One device, one decision, then stop touching it.
3
The Habits That Prevent Most Conflicts
You cannot remove the possibility — offline editing is real life — but you can make it rare:
One editor at a time. The simplest rule in shared work: a document has one person actively editing it. Tell the team; it works better than any setting.
Let devices wake up before you work. Open the laptop, give Syncthing a minute to show "Up to Date", then edit. Editing a stale copy in the first thirty seconds is how conflicts are born.
Close files before you move. Leaving a document open on the office PC, then editing it on the laptop at home, asks for a collision. Close it at the desk; the lock is social, not technical.
Keep the hub always on. A hub that is awake gives every device a fresh copy quickly, shrinking the window in which two stale copies can diverge.
4
What Not to Do
Three reactions make conflicts worse:
Do not bulk-delete conflict files unread. That is deleting someone's work — possibly your own, from the train, that you forgot about.
Do not rename one copy and keep both "just in case" forever. A folder littered with near-identical documents becomes unsearchable, and the next person edits the wrong one.
Do not treat conflicts as corruption and start reinstalling or re-sharing folders. The sync engine is healthy; it is asking a question only a human can answer.
One more reassurance: Syncthing caps how many conflict copies it keeps per file, so an ignored conflict problem clutters rather than explodes — but a weekly glance at your main folders keeps it that way.
🔴 The mindset that fixes conflicts permanently: a conflict file is Syncthing choosing your work over its own guess. Tools that silently overwrite would give you a tidier folder and quietly destroy the other edit. When you see a conflict, the correct feeling is not annoyance — it is relief that both versions survived.
🎥 Watch Healthy Sync Running in the Video
The main Syncthing setup video shows folders reaching Up to Date across three devices — the state that keeps conflicts rare.
Which of the two files is newer — the plain one or the conflict copy?
Neither label means newer in a simple sense. Syncthing keeps one version as the live file based on its internal history tracking, and preserves the other as the conflict copy. The timestamps inside the conflict file's name tell you when the conflict was detected, not which edit is better. Open both and judge the content.
Can I turn conflict files off?
You can set the maximum number of conflict copies to zero in advanced folder settings, but think carefully: Syncthing will then discard the losing edit automatically. On a folder only you ever edit, that may be acceptable. On anything shared or valuable, it removes exactly the safety this guide describes.
A conflict file appeared for a file I never edit. How?
Some programs rewrite files on open or on close — accounting packages, sync-unfriendly editors, and anything that updates an internal timestamp inside the file. From Syncthing's side, the file changed on that device. If it keeps happening with one application, keep that application's data out of two-way sync, or have only one device ever open it.
This guide is part of the Syncthing series by Technical Anshu • Watch the main setup video for the full live build 🙏