Your files stay on your Mac.
WebM packages video and audio in a single container; converting to Ogg Vorbis strips the video stream and re-encodes the audio track into the open Ogg format. The result is an audio-only file accepted by browsers, media players, and Linux software alike. Convertessa runs the conversion entirely on your Mac — your files never touch a server.
Drag one WebM file or an entire folder into Convertessa. Batch mode queues every file at once.
Choose Ogg Vorbis from the output list. Set quality to control how the audio track is encoded — higher settings preserve more detail at the cost of a larger file.
Click Convert. Convertessa extracts and re-encodes the audio offline; your WebM files are never uploaded.
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.
Ogg Vorbis is a lossy format, so re-encoding always involves some quality trade-off. Use the quality slider in Convertessa to balance file size against audio fidelity — higher quality settings preserve more detail.
No. Convertessa converts entirely on your Mac using local codecs. Your WebM files are never uploaded to any server, so the tool works offline and keeps your media private.
Yes. Drop a folder onto Convertessa or run convertessa /path/to/folder --to ogg in the terminal to batch-convert every WebM file in one pass.