Free Photo Library and RAW Editor, a Lightroom Alternative

A free photo library and RAW developer in your browser

MES Darkroom is a free alternative to paid photo-library apps such as Adobe Lightroom Classic. Open a folder of photos (with its subfolders), rate and flag the keepers, add colour labels and keywords, then develop them: white balance, exposure, highlights and shadows, whites and blacks, texture, clarity, dehaze, tone curves, a colour mixer, colour grading, sharpening and noise reduction, lens corrections, perspective, crop and straighten, vignettes, grain, healing spots and masks. Every edit is non-destructive: your original files are never changed, and you can step back through the history or compare before and after at any time.

Edits are kept in this browser, and can also be saved as small .mesdr files next to your photos, so they follow the folder to another computer (OneDrive, Dropbox, iCloud or a USB drive). Export finished photos as JPEG, PNG or WebP at any size, one by one, as a ZIP, or straight into a folder.

RAW files

Camera RAW files are decoded in the browser with LibRaw, the open-source library used by many photo apps, into 16-bit linear colour, so highlights and shadows can be pulled back much further than in a JPEG. While the RAW decodes (a few seconds), the camera's own preview is shown. Sony, Canon, Nikon, Fujifilm, Olympus / OM System, Panasonic, Pentax, Leica, Hasselblad and DNG files all work.

Coming from Lightroom?

In Lightroom Classic, select all your photos and choose Metadata › Save Metadata to Files (Ctrl+S / Cmd+S). That writes an .xmp file next to each RAW. When you open the folder here, ratings, colour labels, keywords and most Develop settings (exposure, tone, presence, white balance, tone curves, HSL, colour grading, sharpening, noise reduction, vignette, grain and crop) are read from those files. Lightroom profiles and masks can't be copied over; the photo may look slightly different. MES Darkroom is not made by, or connected with, Adobe; Lightroom is Adobe's trademark.

Simple and Pro

Simple shows big one-click Looks drawn from your own photo and a handful of sliders: light, colour, detail and effects. Pro shows every panel. Switch any time; nothing is lost.

Keyboard shortcuts

G / D

Library grid / Develop

← →

Previous / next photo

0 – 5

Star rating

P / X / U

Pick / reject / unflag

6 – 9

Red, yellow, green, blue label

\ and Y

Before / after, side-by-side split

R, Q, M, W

Crop, healing, masks, white-balance picker

J

Show clipped highlights (red) and shadows (blue)

Z or Space

Zoom 100% / fit

Ctrl+Z / Ctrl+Shift+Z

Undo / redo

Ctrl+Shift+C / Ctrl+Shift+V

Copy / paste develop settings (to every selected photo)

F

Fill the browser window

Questions

Are my photos uploaded?

No. Everything happens in this browser tab: your photos are read from the folder you open, processed on your graphics card (WebGL), and exported back to your computer.

Where are my edits saved?

In this browser's storage, keyed by file name and size. Turn on "Save edits next to the photos" in Settings to also write a small .mesdr file beside each edited photo, and use "Back up my edits" to keep a copy of everything.

Which browser works best?

Chrome, Edge, Brave or Opera on a computer can open a folder and save next to the photos. In Brave, turn on brave://flags/#file-system-access-api for that. Safari and Firefox can open a folder and edit, but save exports as downloads.

Can I retouch, add text or combine pictures?

Use "Edit in Photo Editor" (in Develop) to send the developed photo to the MES Photo Editor, which has layers, selections, a clone stamp, text and AI background removal.