Subly — AI subtitles on device

Subly turns your short videos into caption-ready clips in seconds — and everything happens right on your iPhone. Your video never leaves your device for transcription: speech recognition runs fully offline, powered by Whisper AI. Perfect for Reels, Shorts, Stories and any vertical clip up to a few minutes long. Pick a video from your gallery, get an accurate transcript, polish it, choose a style — and save a finished video with burned-in subtitles back to your gallery. WHY SUBLY • 100% on-device transcription — no cloud, no account, no uploads • Works offline — transcribe on a plane, in the subway, anywhere • Fast: optimized Whisper models tuned for mobile • Multilingual: recognizes speech in dozens of languages POWERFUL SUBTITLE EDITOR • Word-accurate segments synced to your video • Tap any subtitle to fix text, timing or position • Drag, resize and reposition captions directly on the video • Video pauses automatically while you edit — never lose your place BEAUTIFUL CAPTION STYLES • A library of ready-made caption styles, live-previewed on your actual video • Fonts, colors, backgrounds and sizes that look identical in preview and in the final export • Apply a style to one segment or to the whole video at once EXPORT YOUR WAY • Burn subtitles directly into the video and save to your gallery • Share the finished clip to any app • Or export subtitles as SRT / VTT files for use in other editors PRIVATE BY DESIGN Speech recognition happens entirely on your device. Your videos and audio are never sent to a server for transcription. CHOOSE YOUR MODEL Download the Whisper model that fits your needs — smaller for speed, larger for accuracy. Models are stored on-device and work without a network connection. Subly speaks your language: the app interface is available in 34 languages. Got feedback or a feature request? We'd love to hear from you — leave a review or reach out through the support page.