Convert Canon CR3 to JPG without uploading your photos

You can convert Canon CR3 raw files to JPEG in your browser without sending them to anyone: open them in Light, Madosuite’s raw developer, and export JPEG. The photos stay in a Linux machine that runs inside your browser tab, on your own device.

Here is how, which CR3 files work today, and what to check first.

Why “no upload” matters for raw files

Raw files are large, and a shoot is often hundreds of them. Upload-based converters have to send every file to a server and send the JPEGs back. That takes time, and your photos sit on someone else’s computer: a client’s event, your family, your home.

Madosuite works differently. It runs a Linux machine in the browser on your device. Files you bring in go to that machine’s home folder, in your browser. They are not uploaded to us. No account is needed. One thing to know: clearing the site’s data in your browser deletes those files, so download what you want to keep.

Which CR3 files Light can open

CR3 is Canon’s raw format, and it comes in more than one variant. Light’s documentation lists what it decodes today:

Lossless CRX Bayer CR3 files
C-RAW CR3 files, versions 0x100 and 0x200

Other CR3 variants do not decode yet. For those, Light uses the JPEG preview the camera embedded in the file, when there is one. You can look at that preview, but you are not developing the raw sensor data. Light’s documentation also notes that colour for Canon CR3 is a guarded estimate built from camera JPEGs, not a measured calibration.

If your photo opens and edits look right, your variant works. If it looks like a fixed preview, it is likely one of the variants not supported yet.

How to convert CR3 to JPG

Go to madosuite.com and open the desktop.
Open the Store and add Light. It takes one click.
Open Files, press Upload, and pick your .cr3 files.
Open the photos with Light.
Develop each one (see the next section), or leave it as it is.
Export as JPEG. You can set the size, a file-size limit, output sharpening and naming, and export a batch.
Open Files and download the JPEGs.

A quick develop before you export

Light is non-destructive. Your CR3 is never changed; edits are stored as settings. A short pass is often enough:

White balance: use Auto, a preset, or the eyedropper on something that should be neutral grey.
Light: Exposure, Contrast, Highlights, Shadows, Whites and Blacks. Pulling Highlights down helps a bright sky.
Effects: a little Texture or Clarity for detail.
Crop and straighten, with locked ratios such as 3:2, 4:5 or 16:9.

To give a whole set the same look, edit one photo, then copy and paste or sync its settings to the others. There are also 41 built-in presets, each with an Amount slider.

Keep the original

A JPEG is good for sharing, but it cannot be developed again the way the raw can. Keep the CR3 files.

If you want an open raw format for archiving, Light can also export DNG (raw or rendered).

What may not carry over

Light is an alpha. Its documentation calls it “young and moving fast”. Know these limits before you rely on it:

Some CR3 variants do not decode yet, as above. Light falls back to the embedded preview.
Camera colour is estimated, not measured, so colour may differ from Canon’s own look.
AI Denoise in Light needs separately installed weights and works on Bayer raws. Super Resolution and generative fill are not there.
Camera lens profiles of its own are not there yet. Lens corrections embedded in DNG files are used.
In the browser, GPU rendering through WebGPU is still in progress, so large raws can take time to render.

Light is one of the ArtCraft team’s open-source Crafting Apps (MIT or Apache-2.0), under a Madosuite name.

For the converter page, go to CR3 to JPG.