Your files stay on your Mac.
BMP is an uncompressed raster format with no built-in compression, producing files far larger than necessary for typical use. HEIC uses HEVC encoding to store the same image data at a fraction of the size — you control the quality trade-off. Convertessa does the conversion entirely on your Mac; no file ever leaves your machine.
Drag one BMP file or an entire folder into Convertessa. The app queues every BMP it finds for conversion.
Choose HEIC from the output format list. Because HEIC is a lossy format, you can set quality to balance fidelity and file size before converting.
Click Convert. Convertessa writes HEIC files at the destination you choose, strips EXIF metadata, and preserves the original resolution. Source BMP files are left untouched.
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.
HEIC uses lossy compression, so some image data is discarded. Convertessa lets you set quality before converting — higher values preserve more detail at the cost of larger files, lower values shrink files further with more compression.
Yes. Drag a folder onto Convertessa and every BMP inside is queued automatically. From the command line: convertessa ./folder/ --to heic processes the entire folder in one pass.
No. Convertessa runs entirely offline on your Mac. BMP files are read and written locally — nothing is sent to a server or cloud service at any point.