# Ask HN: Open source lightroom alternative, how do I improve it? > Source: > Published: 2026-11-04 19:22:20+00:00 #1 Ask ### Say what you want Type “golden hour”, “down exposure by ten points” or “paste the edits from the previous photo”. A small Rembrandt thinks it over, then moves each slider while you watch, with Undo. `⌘ K` Ask Develop RAW files, ask for a look in plain words, or just drag on the photo. Free on your own computer, the code is public, and your edits are plain XMP files next to your photos. #0 Develop We think you should *own* your editor the way you own your *camera.* So Rembrandt is free on your computer, *open* for anyone to read, and paid only where it costs us money every month: keeping your photos *online.* The code is under the GPL, so nobody, including us, can take it back or close it later. No investors and no ads. Your photos are never used to train anything. If we ever stop, you still have the app, the source and your edits in an open format. Every slider, mask and AI tool runs on your own machine. Your photos never leave it unless you send them somewhere. #2 Touch Drag up or down on any part of the picture to lighten or darken that tone, left or right to change that colour. A label shows what you’re about to change; the sliders follow. #3 Refocus Measures how far out of focus the photo is and brings the detail back, even from heavy blur, on the subject or the whole picture. Deconvolution on your GPU, no upload. #4 Super Resolution 2× and 4× with real detail, or Restore at the same size to sharpen soft and slightly out-of-focus shots. Runs on your GPU, through Metal on Apple silicon. #5 Masks Brush, linear and radial gradients, colour and tone ranges, each with its own sliders. Subject, background, object and depth masks are found by AI on your device. `M` Masks`O` Overlay #6 Remove Click a dust spot or paint over something you don’t want. Rembrandt fills it from a matching patch; drag the source if you want a different one. `Q` Remove`H` Hide spots #7 Compare Split or side by side with a divider you can drag. The histogram updates as you work and can mark clipped highlights and shadows. `Y` Split`\` Original #8 Library Albums, stars, flags, smart collections and search. Point it at a folder and it stays in sync, or bring a Lightroom Classic catalog with its edits. #9 Self-host One command serves the editor and a photo folder to every browser on your network. It updates itself from Settings. Open a folder and keep your photos where they are, or bring a whole library over with its ratings, flags and edits. Computer · self-hosted $0 forever iPhone · iPad · Android // coming soon $30 once Yes. The desktop apps and the self-hosted web editor are free with nothing held back and no watermark. The only paid thing is the phone unlock. There is no Rembrandt Cloud yet; if it comes, it will be optional. No. There are no accounts: Rembrandt Cloud doesn’t exist yet, and everything works offline on your own computer. In XMP sidecar files next to your photos. Your originals are never changed, and other editors can read the edits. RAW files from about 1,000 camera models, decoded with LibRaw. JPEG, PNG, WebP, AVIF and TIFF work everywhere; HEIC where your system can open it. Your photos and edits on your devices stay where they are. Photos stored online stay readable so you can download them. Yes. Import the .lrcat file and Rembrandt brings over your photos, ratings, flags and the edits it can translate. Something broken, an idea, or a camera that doesn’t open? Open an issue on GitHub. New versions are announced on the releases page.