- Are my RAW files uploaded to a server?
- No. Every step of the conversion happens inside your browser using WebAssembly (a compiled version of dcraw) and the HTML Canvas API. Your files are never transmitted over the network. You can even disconnect from the internet after the page loads and the converter will still work.
- What is the difference between NEF, ARW, CR2, and DNG?
- These are proprietary RAW formats created by different camera manufacturers: NEF is Nikon's format, ARW is Sony's, CR2 (older) and CR3 (newer) are Canon's. DNG (Digital Negative) is an open standard from Adobe used by Leica, GoPro, Ricoh, and as a universal archival format. All store unprocessed sensor data. This tool converts them all to the universal JPEG (or PNG) format that any device or app can open.
- Why convert RAW to JPEG at all?
- RAW files are 10–30× larger than JPEGs and can only be opened by specialist software (Lightroom, Capture One, etc.). JPEG is universally supported on every device, social platform, and website. Converting is necessary before sharing, emailing, or uploading photos. PNG is an alternative if you need lossless compression without JPEG artefacts, useful for printing or compositing.
- What JPEG quality should I choose?
- Quality 85–92 is a good balance — it produces small files with no visible degradation compared to 100. Quality 100 makes files 3–5× larger than 90 with marginal visual improvement. For web sharing, 80 is often sufficient. For printing or archiving, 90–95 is recommended. PNG is lossless and is the right choice when file size is no concern and you need pixel-perfect accuracy.
- How large a batch can I convert at once?
- There is no hard limit, but each 20–40 MB RAW file decoded to full resolution may use 100–300 MB of browser memory during processing. Processing is done one file at a time to keep memory usage manageable. For very large batches (50+ files) it is best to convert in groups of 10–20. Modern browsers on a desktop machine handle typical batches of 20–30 RAW files comfortably.