Meeting transcription that never leaves your Mac.

Who needs local transcription

Some calls simply cannot be uploaded to a transcription service: attorney–client conversations, patient sessions, source interviews, M&A discussions, anything under NDA. The moment audio hits a vendor’s cloud you inherit their retention policy, their subprocessors, their breach surface — and a data-processing agreement to negotiate. Local transcription removes that whole category of problem: there is no vendor in the loop, so there is nothing to agree, audit, or trust.

What “on-device” means in echo99 — precisely

• Recording — your microphone and your Mac’s audio output are captured as two separate WAV files, straight to local disk.
• Speech-to-text — recognition models are downloaded once to your Mac and run locally. After that download, everything works with Wi-Fi off.
• Speaker labeling — diarization also runs locally: your mic track is “Me”, other voices become “Them-1”, “Them-2”, …
• Networking — echo99 ships with limited telemetry: a launch-time update check that sends an anonymous install id. Nothing more. Audio and transcripts are never uploaded, and there is no account to create.

Your data lands in ~/Documents/echo99/ as plain WAV and JSON files. Deleting a folder there is the entire data-deletion story — helpful when your work is governed by data-minimization rules, though whether your recording practice satisfies any given regulation is a question for your counsel, not an app.

What you get after each call

• transcript.txt and transcript.json — the full conversation with speaker labels and timestamps, readable and machine-parseable.
• mic.wav + system.wav — the clean source audio, one track per side of the conversation, kept separate on purpose.
• metadata.json — when it was recorded and with what settings.

Honest limits

• The transcription models download once from the internet (a few hundred megabytes); after that, echo99 is fully offline-capable.
• On-device recognition is strong, but heavy accents, crosstalk, and bad audio still produce errors — same as any transcription, cloud or local. A custom-vocabulary option helps with names and jargon.
• Apple silicon transcribes fastest; Intel Macs are supported but noticeably slower.

New to echo99? See getting started for setup and your first recording.

Related guides: Transcribe interviews, Record system audio