Your files stay on your Mac.
Convertessa reads MPEG-TS transport streams and rewraps the audio into Matroska (.mka) files entirely on your Mac—no upload, no internet required. Set quality before you export to control the fidelity-to-size trade-off. Convert a single clip or batch-convert a whole folder in one pass.
Drag one or more .ts files—or an entire folder—into Convertessa. The app reads each transport stream and queues it for conversion.
Choose Matroska from the output list. Because Matroska Audio is a lossy format, you can set quality here to dial in the fidelity-to-file-size balance before committing.
Click Convert. Convertessa processes every file locally on your Mac—files never leave your machine and no internet connection is needed. Your .mka files are ready in moments.
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 runs entirely offline. Your MPEG-TS files never leave your Mac and no internet connection is required at any point.
Yes. Drop a folder onto Convertessa, or run convertessa /path/to/folder --to mka in the terminal to batch-convert every .ts file inside in one pass.
Matroska Audio encodes with a lossy codec, so the quality slider trades file size against audio fidelity. Higher quality produces larger files with better fidelity; lower quality produces smaller files.