Subtitle Converter
SRT ↔ SMI · Sync · Merge
Convert between SRT and SMI, adjust sync timestamps, and merge any two subtitle tracks into one. 100% private in browser.
Drop subtitle file here or click to browse (.srt, .smi)
Subtitle Preview
Total 0 cuesA free subtitle utility for converting and editing SRT and SMI subtitles for media players and Smart TVs.
Your subtitle files are never uploaded to a server. All parsing, conversion, and merging happen entirely in your browser memory, keeping your transcripts and personal subtitles 100% private.
- Bidirectional SRT ↔ SMI Conversion: Seamlessly converts timestamps, line breaks, and SAMI CSS tags.
- Precision Sync Adjustment: Shift subtitle timing forward or backward by milliseconds or seconds.
- Merge two subtitles: Aligns two tracks along the timeline and stacks them, with your choice of which goes on top. It matches on timing alone, so any pair of languages works.
Features
SRT ↔ SMI Conversion
Convert between SAMI (.smi) and SubRip (.srt) subtitle formats seamlessly.
Precision Sync Adjustment
Shift subtitle timing forward or backward using quick nudges (±0.5s, ±1s, ±5s) or custom millisecond offsets.
Merge two subtitles (top/bottom)
Pairs two tracks by overlapping intervals and stacks them, with your choice of order. Any language pair works.
Independent Sync Offsets
Shift each track separately before merging when their baselines differ.
Real-time Timeline Preview
Inspect cues, timestamps, and lines in real-time before downloading.
100% Private Local Processing
Zero server uploads. All processing happens on your local device.
Usage
- Price
- Free (No ads)
- Formats
- SRT (.srt), SMI / SAMI (.smi)
- Sync Unit
- Milliseconds (ms) / Seconds (s)
- Merge layout
- First on top / Second on top
- Data Storage
- Zero server storage (100% local)