Your files stay on your Mac.
Convertessa reads each .hdr file, encodes it as an AVIF image using the AV1 Image File Format specification, and writes the result alongside the original. The output retains the original resolution and strips embedded metadata. Because AVIF supports HDR content, the high dynamic range data from your source files is preserved through the conversion.
Drag one .hdr file or an entire folder of them onto Convertessa. Nothing is uploaded — all processing runs locally on your Mac.
Pick AVIF from the output format list. Set quality to control the trade-off between file size and fidelity before converting.
Click Convert. Convertessa processes every file and saves the AVIF images next to the originals. Embedded metadata is stripped from each output file.
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. AVIF supports HDR content, so the high dynamic range information encoded in your Radiance HDR source is carried through to the output file.
AVIF is a lossy format. A higher quality value retains more detail but produces a larger file; a lower value shrinks the file at the cost of some fidelity. Convertessa lets you set quality before each conversion run.
Yes. Drop a folder onto Convertessa or pass a directory on the command line (convertessa ./photos/ --to avif) and every Radiance HDR file inside is converted in one batch.