Megaphone

Megaphone is a free, open source dictation app for Mac that transcribes speech and cleans it up entirely on the device. Apple's SpeechAnalyzer provides live transcription while the speaker talks, and Apple's on device Foundation Models then tidy the result, so voice data is not sent to the cloud. Its main capabilities are a private personal dictionary of names, products, acronyms and technical terms that improves both transcription and cleanup; three cleanup modes named Smart, Basic and Exact, where Smart uses the on device language model with a deterministic fallback; and app context awareness, so output adapts to the application in use. Voice macros are supported, and a run log records activity. Saying the wake phrase Hey Megaphone starts Inline AI, where the on device model answers or rewrites text inside whatever app has the cursor, with no separate chat window or copy and paste. The site shows it used alongside coding agents such as Claude Code, Codex and Cursor. Dictionaries can be exported to and imported from a JSON file to move between Macs. It is aimed at Mac users, especially developers, who want fast, private voice input. The app requires macOS 26 and Apple silicon. Megaphone is free and the source is published for inspection.