Blog · Developing
Developing RAW
in a browser
Culling gets the attention, but the harder half is what happens to the frames you keep. Here is what a browser can develop locally, and precisely which of it survives the trip into Lightroom.
Published September 7, 2026 · 7 min read
Rawnd runs on a desktop browser — it needs access to the folder your RAW files are in. Open this page on your computer.
01 The short answer Before the detail
A browser can develop a RAW file properly: exposure in stops on Camera Raw's scale, a point curve, eight HSL bands, linear and radial masks, detail and a crop, all on the GPU with nothing uploaded. What it cannot do is hand all of that to Lightroom. An XMP sidecar carries the tone and colour sliders; the curve, HSL, masks, vignette and white balance stay behind, and knowing which is which is the difference between a round trip and a surprise.
What a browser actually develops now
The list is longer than most people expect, because the assumption is still that a page can show you a photograph but not work on one. Eight modules run here, and every one of them runs on your own GPU on decoded sensor data rather than on a JPEG preview.
- Tone: exposure, contrast, highlights, shadows, whites, blacks, temperature and tint.
- Curve: a point curve, the control that does what no slider combination quite does.
- Colour and HSL: saturation and vibrance, then hue, saturation and luminance across eight bands from red to magenta.
- Masks: linear and radial, feathered, invertible, each carrying its own set of tone and colour adjustments.
- Detail: texture, sharpening, luminance noise reduction, and chromatic aberration with an automatic mode.
- Effects and crop: vignette, rotation, quarter turns and aspect ratios.
Why any of it can travel at all
A sidecar does not carry an image. It carries numbers, and numbers only mean something to the program reading them if both programs agree on the scale. That agreement is the whole reason a round trip is possible here and the whole reason parts of it are not.
Exposure travels because it is written in stops and Camera Raw reads stops. A mask does not travel because there is no shared way to say where it sits and how hard its edge is. Everything in the table below sits on one side or the other of that single question, and nothing else decides it.
The round trip, stated exactly
Edits leave as XMP sidecar files written next to the originals, which is what Lightroom, Camera Raw and Bridge read on import. The format is the constraint here, not the ambition, and the honest version of this section is the list of what does not survive.
| Adjustment | Into an XMP sidecar |
|---|---|
| Exposure, in stops | Carried |
| Contrast, highlights, shadows, whites, blacks | Carried |
| Texture, vibrance, saturation | Carried |
| Sharpening, luminance noise reduction | Carried |
| White balance | Not carried |
| Tone curve | Not carried |
| HSL | Not carried |
| Masks | Not carried |
| Vignette and defringe | Not carried |
Why white balance is the one that surprises people
It looks like the easiest field on the list, and that is exactly why the row says not carried. The slider here is an offset from what the camera recorded; Camera Raw's is an absolute value in Kelvin. Converting between the two means guessing at the camera's own reference, and a wrong guess lands every photograph in the export on a colour cast nobody asked for.
So the sidecar says nothing about it, and Lightroom opens the file on As Shot, which is where it started. A field left blank is recoverable in one click. A field filled in wrongly across four hundred frames is an afternoon.
Which half of the work to do where
The practical answer is not that one tool wins. It is that the sidecar boundary tells you where to put each kind of edit, and that boundary is stable enough to plan around.
Do the culling and the tone pass in the browser, because that is the part that carries and the part that touches every frame. Export the JPEGs directly from here for the ones that are finished. Keep the curve, the HSL work and the masks for the frames that earn individual attention, and either finish those here and export the file, or start them again in Lightroom knowing the tone work arrived ahead of you.
Checked against the shipped build on 7 September 2026.
99 Questions Asked more than once
Will Lightroom see my ratings as well as the tone work?
Yes. Ratings and rejects are the part of a sidecar that has been standard the longest, so a cull done here arrives intact even where an adjustment would not.
What happens if I edit the same frame in both?
Whichever program writes the sidecar last wins, because there is one file and no merge. In practice that means finishing a frame in one place: send the tone pass over, then work in Lightroom, rather than moving back and forth.
Why does the tone curve not carry into Lightroom?
It is representable in XMP, and it is a mapping worth getting exactly right rather than approximating. Until it is right, writing nothing is the honest option — a curve that is close but wrong is harder to notice than one that is absent.
Does developing cost anything?
No. Every module described here is free and unlimited, one photo at a time. The paid tier is for what acts on a selection: assisted culling, batch export, pasted settings and your own presets.
Open a card. Nothing to install.
Ten seconds from now you are culling. Close the tab and your ratings are still here next time.
Rawnd runs on a desktop browser — it needs access to the folder your RAW files are in. Open this page on your computer.
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