Your files stay on your Mac.
Converting WebM to AIFF extracts the audio track and writes it as uncompressed PCM — the same format used in professional audio workstations. Files never leave your Mac; the conversion runs entirely on-device with no upload required. AIFF preserves the full resolution of the source audio without lossy re-encoding.
Drag one WebM file or an entire folder into Convertessa. Batch processing handles as many files as you need in one pass.
Pick AIFF from the output format list. Convertessa keeps the full audio resolution from the source WebM — no lossy step is introduced because AIFF is uncompressed.
Click Convert. The extracted audio is written to AIFF on your Mac — nothing is uploaded and no internet connection is required.
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.
No. AIFF stores audio as uncompressed PCM, so the conversion is lossless — the output preserves the full resolution of whatever audio was encoded in the WebM file.
Convertessa extracts only the audio track. The video content in the WebM file is discarded, and the output is a standalone AIFF audio file.
Yes. Drop a folder onto Convertessa or run convertessa *.webm --to aiff in your terminal to batch-convert every WebM file in one command.