Frequently asked questions

Is it really free?

Yes. Free to download, free of ads, free of a subscription, and open source under the GPL. There is no paid tier and no plan for one.

Nothing funds it either. See how to help.

Does it upload my photos?

No. There is no network code in the app at all: no telemetry, no analytics, no account, no crash reporting. It works with the network switched off, and always will.

Is it an editor?

No. Cullant chooses which frames survive. Editing happens in Lightroom, Capture One, Darktable or wherever you already work, and Cullant hands over through XMP sidecars.

Will it change my files?

Only when you commit, and only in the ways you queued: a delete, a move, a copy, a sidecar. It never touches the pixels of a photo. Rotation is stored as a flag.

What does it put in my folder?

One .cullant folder holding a database and a thumbnail cache. Delete it and your photos are untouched. You lose your decisions, nothing else.

Why is a photo blank in the grid?

Three usual reasons:

• It is a HEIF and this machine has no decoder. See HEIF and iPhone photos.
• It is a video and ffmpeg is not installed.
• It is an older Panasonic .RAW, which holds no preview at all. See the formats page.

In the first two cases, installing the missing piece fills the blank in on the next look.

Why is my RAW preview soft?

You are seeing the JPEG your camera wrote inside the file, which is what makes Cullant fast. Most cameras write a full-size one. A few, such as a Sigma fp, write a very small one, and there is nothing to be done about it short of a full decode.

Does it work with Lightroom?

Yes, through XMP sidecars: rating, flag, colour label and orientation. Capture One reads them too. See XMP and Lightroom.

Can I use it on my phone?

On Android, yes. iOS and iPadOS are scaffolded but not built yet. See Cullant on Android.

What about macOS and Linux?

The code runs on both. Nobody produces a packaged build for either yet, so you build it yourself. See Build from source.

Is it stable?

It is beta and it says so on every page. It has a backend test suite and a corpus of real camera files that it is run against. It also has known gaps, listed on the formats page.

The design limits the damage a bug can do: nothing changes on disk except during a commit that you read first, and deletes go to the Recycle Bin.

Can I help?

Yes, and the most useful thing is not money. Send RAW files from your camera bodies. The decoder cannot be tested against a body nobody has files from. See how to help.