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About this tool
Preview RAW photos with a simple exposure control, then export to JPEG.
RAW Photo Developer opens a camera RAW file (DNG, NEF, CR2, ARW) or any ordinary image in your browser, applies a one-click exposure adjustment, and exports a high-quality JPEG using FFmpeg compiled to WebAssembly. You pick -1 stop, neutral, or +1 stop, and the tool runs an FFmpeg `eq` filter at brightness ±0.12 with a gentle contrast lift of 1.04 and saturation of 1.03, writing the result at JPEG quality -q:v 2. It is a fast exposure preview and format conversion step, not a colour-managed RAW pipeline, so treat it as a quick look rather than a replacement for a full raw converter.
Open RAW Photo Developer on AltFTool — it loads instantly in your browser.
Choose a Source file — the picker accepts .dng, .nef, .cr2 and .arw alongside ordinary image types.
Set Exposure to -1 stop, neutral or +1 stop and press Process locally; the button counts up as "Processing 45%" while FFmpeg WebAssembly runs.
The frame downloads as altftool-raw-photo-developer.jpg written at -q:v 2, and the Local processing report lists File, Size, Type and Profile with the FFmpeg decoder log underneath.
The file picker accepts .dng, .nef, .cr2 and .arw alongside standard images, so you are not forced to convert first.
Exposure collapses to three choices — -1 stop, neutral, +1 stop — mapped to a fixed brightness ±0.12 with a mild contrast and saturation lift.
Progress and the raw decoder output are visible while it runs, so when a camera format will not decode you can see exactly why.
The upload field accepts .dng, .nef, .cr2 and .arw, plus any regular image type. Whether a given file actually decodes depends on the browser FFmpeg build and the specific camera model, since some proprietary raw variants are not supported by the bundled decoder.
It sets the brightness term of an FFmpeg `eq` filter to +0.12 for +1 stop, -0.12 for -1 stop, or 0 for neutral, and in every case applies contrast=1.04 and saturation=1.03. That is a fixed adjustment rather than a true stop-accurate exposure calculation, so the labels are approximations.
Exports are written with FFmpeg's -q:v 2, the second-highest quality step on its 2-31 JPEG scale, so files are large but visually close to the decoded source. There is no option to trade quality for size here.
No. There is no colour management, no camera profile, no white-balance-by-temperature and no highlight recovery — it is a single fixed brightness/contrast/saturation pass plus a JPEG write. Use it to preview or hand off a file quickly, and use a real raw converter when the edit matters.