Subly
Updated 2026-06-28
Add Captions to Any Video, Right on Your iPhone
Clear, tested guides for subtitling and captioning video on iPhone — including the things web tools can't do: fully offline, private, and watermark-free.
- iPhone-specific
- Offline & private
- No watermark
Captions that work fully offline
100%on-device
0uploads, ever
Nowatermark
SRT+VTTexports
Fully offlineTranscribe and export in airplane mode — your video never leaves the phone.
No watermarkClean exports in your own style, with no logo stamped across the video.
SRT & VTTBurn captions in for social, or export a subtitle file when you need one.
- SRT
- VTT
- MP4
- Reels
- TikTok
- Shorts
- Karaoke
- Hardcode
How captioning on iPhone works
Three steps, all offline — your footage never leaves the phone.
Pick your videoOpen any clip from your camera roll — no upload, no account.
Transcribe on-deviceSubly turns speech into captions right on your iPhone, even in airplane mode.
Style & exportBurn captions in, or save an SRT/VTT — clean and watermark-free.
Popular guides
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