Your files stay on your Mac.
Convertessa reads your Flash FLV files and writes Ogg Vorbis audio directly on your Mac — no upload, no internet required. Set quality to balance file size against fidelity, then convert a single file or a whole folder in one pass. The output carries no embedded metadata from the original.
Drag one or more FLV files into Convertessa, or point it at a folder to queue every Flash file inside.
Pick Ogg Vorbis from the output list. Dial in the quality setting to control how much fidelity you trade for smaller files.
Hit Convert. Convertessa processes every file locally — nothing leaves your Mac — and writes the Ogg Vorbis files alongside the originals or to a folder you choose.
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. Ogg Vorbis is a lossy format, so a lower quality setting produces smaller files at the cost of some audio detail. Convertessa lets you set quality before conversion so you can tune the result to your needs.
No. Convertessa runs entirely offline. Your Flash files are read and written on your Mac only — nothing is sent to a server.
Yes. Drop a folder onto Convertessa or run convertessa ./folder --to ogg in the terminal and every FLV file inside will be converted to Ogg Vorbis in one pass.