Your files stay on your Mac.
Convertessa decodes each Nikon RAW (NRW) file and re-encodes it as WebP, a modern lossy image format with efficient compression. You pick the quality level before converting, letting you balance file size against visual fidelity. Everything runs locally on your Mac — no upload, no internet connection required.
Drag individual .nrw files or an entire folder into Convertessa. The app reads Nikon RAW files directly — no third-party pre-processing step needed.
Choose WebP from the output list, then set your preferred quality level. Higher quality retains more detail; lower quality produces a smaller file.
Click Convert. Convertessa processes every file on your Mac and saves the resulting WebP images. No upload, no cloud, no waiting on a server.
Images, audio, video, documents, archives and eBooks — all converted natively, right on your Mac.
Pick a format you have — see everything Convertessa can turn it into.
Convert hundreds of files at once with per-type group defaults and individual overrides.
First-class support for HEIC, AVIF and WebP — encode and decode, both ways. Read JPEG XL and a dozen more modern formats too.
Drop files anywhere on the window. Native, instant, and exactly what you’d expect on a Mac.
Dial in compression, resolution and bitrate. Keep originals pristine or shrink for sharing.
Never overwrite a file by accident. Convertessa appends safe suffixes automatically.
Every job is logged locally. Re-run a previous conversion or revisit recent outputs in a click.
Bundle your converted files straight into a single ZIP, TAR or 7z — packaged and ready to share the moment a job finishes.
Right-click any file in Finder and choose Convert. A Quick Action handles it on the spot — no need to open the app first.
Shrink Convertessa to a tidy mini window that tucks into a corner — just a drop zone and a format picker for quick, one-off conversions.
No cloud. No account. No upload. Every conversion happens entirely on-device, using the power already in your Mac. What you convert is nobody’s business but yours.
Script conversions, wire them into your build, or batch a folder from the terminal. The same engine, no GUI required.
Read the full CLI documentation →Shrink Convertessa down to a small, focused window — drop, convert, done, with your recent conversions one click away.
macOS 14+ · Apple Silicon & Intel
New formats, new features, and fixes — every release, on the record.
Yes. Convertessa preserves the full resolution captured by your Nikon camera. No scaling occurs during conversion.
That depends on the quality value you set before converting. At high quality values the difference from the original is negligible; lower values produce smaller files with a more visible reduction in fidelity. Convertessa lets you choose the trade-off.
Yes. EXIF and embedded metadata — including location data and camera model info — are removed during conversion and are not carried over to the WebP file.