Your files stay on your Mac.
Radiance HDR (.hdr) is a high dynamic range image format that stores floating-point luminance data, capturing a far wider tonal range than standard formats. Convertessa reads your .hdr files and converts them to AVIF, JPG, PNG, TIFF, or WebP — entirely on your Mac, with no files uploaded anywhere. Drop a single image or point Convertessa at a whole folder to batch-convert in one pass.
Drag a single .hdr file — or an entire folder of HDR images — onto Convertessa. The app reads every file locally; nothing leaves your Mac.
Pick AVIF, JPG, PNG, TIFF, or WebP from the output list. Each option converts the full HDR image to that format using your Mac's processor.
Click Convert. Convertessa processes every file and places the results in the folder you choose — resolution preserved, EXIF stripped.
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 — JPG and PNG are standard dynamic range formats and cannot store the extended luminance data in an HDR file. If retaining more tonal detail matters, choose TIFF or AVIF from the output list instead.
Yes. Convertessa removes EXIF and embedded metadata from the output files, leaving clean images ready for publishing or archiving.
Yes. Drag a folder onto Convertessa, or run convertessa ./folder/ --to png in the terminal. Every .hdr file inside is converted in one pass.