iSubtitle

iSubtitle lets macOS users embed soft subtitle tracks, chapter markers, and full metadata into video files for seamless playback on iTunes or the TV app and across Apple devices such as iPhone, iPad, iPod, and Apple TV. It accepts a range of subtitle formats—including .srt, .ass/.ssa, .stl, .vtt—and can fetch subtitles online via the companion Submarine app, providing an instant preview before export.

The app automatically retrieves and applies movie or TV‑show metadata, artwork, and chapter information, while also allowing manual editing of all fields. Export relies on an integrated FFmpeg engine that analyses the source file, passing through compatible tracks without re‑encoding when possible, which speeds up processing and ensures device compatibility.

Resulting files contain resolution‑independent soft subtitles rendered in real time, supporting retina displays and preserving the original video quality. iSubtitle therefore serves as a streamlined tool for preparing media libraries that integrate tightly with Apple’s ecosystem.