What does Subtitle Utility do?
Tubelexity combines four practical subtitle tools: convert SRT and VTT, shift cue timing, merge two subtitle files and burn existing captions into video. It preserves multiline cues, validates common syntax problems and previews changes before download. Subtitle text and video remain local; the utility does not generate or transcribe captions.
How to use Subtitle Utility
- 1Choose Convert, Shift, Merge or Burn into video.
- 2Load local SRT or VTT files and review any validation warnings.
- 3Adjust timing, order or burn-in styling and preview the result.
- 4Download the converted subtitle or locally rendered video.
Supported inputs and outputs
Inputs
SRT, VTT, MP4/MOV/WebM for burn-in
Outputs
SRT, VTT, MP4 with burned-in subtitles
Practical uses
- Converting SRT captions to WebVTT
- Fixing a subtitle timing offset
- Combining two caption tracks
- Rendering permanent captions into a video
Browser and media limitations
- Malformed cues require correction before export.
- Negative shifts may clamp cues at zero.
- Burn-in rendering downloads FFmpeg on first use.
- Burn-in glyph coverage depends on the bundled subtitle font.
How local processing works
Subtitle parsing happens in the browser. Burn-in export uses locally loaded FFmpeg.wasm; subtitle text and video are not transmitted to Tubelexity.
Frequently asked questions
Can I convert SRT to VTT?
Yes. The converter preserves cue timing and multiline text, normalizes line endings and downloads a VTT file.
Can I shift subtitles earlier or later?
Yes. Apply a positive or negative offset in seconds or milliseconds and preview the changed cues.
Can I merge two subtitle files?
Yes. Choose their order, optionally offset the second file and review overlap warnings before download.
Can I burn subtitles into a video?
Yes. Load an existing SRT or VTT file, adjust styling and render captions locally into an MP4.
Does this tool generate subtitles automatically?
No. It edits subtitle files you already have and does not use transcription or AI.