Subtitle Converter & Editor

What does this tool do?

Subtitle Converter and Editor reads six common subtitle formats, converts between them, fixes their timing, and lets you edit the cues — entirely inside your browser. Paste subtitles or open a file, choose an output format, and download the result.

How to use

1. Convert existing subtitles — in the Convert tab, paste or open a file, choose the output format, then copy or download.
2. Create from scratch — switch to Create / Edit and start a blank project or generate cues from plain text.
3. Edit — change each cue's start and end time and text in the table, add or remove rows, and split or merge as needed.
4. Finish — pick a format in the export bar at the bottom and download.

Supported formats

• SRT (SubRip)
• WebVTT (.vtt)
• ASS (Advanced SubStation Alpha)
• SSA (SubStation Alpha)
• MicroDVD (.sub, frame based)
• SAMI (.smi)

The format is detected automatically, and you can override it if a file is ambiguous. ASS and SSA keep their script header and styles when they stay in ASS/SSA; converting to SRT or WebVTT strips the override tags so the text stays readable.

Timing and sync

• Shift every cue by a number of seconds, forwards or backwards.
• Convert frame rate between 23.976, 24, 25, 29.97, and 30 fps, useful when subtitles were timed for a different release.
• Fix overlaps so one cue never runs past the next.
• MicroDVD files use frames, so a frame rate is needed; it is read from the file header or can be set manually.

Editing cues

The cue table lists every subtitle with editable start and end times and text. Add, delete, split at the midpoint, or merge a cue with the next one, and reorder rows with the arrow buttons. Cleanup helpers strip formatting tags, drop empty cues, and re-wrap long lines to a chosen character width.

Create subtitles from scratch

No subtitle file? Start a blank project with New subtitle and add cues by hand, or paste plain text into From text and let the tool build the timeline. Text can be split by line, paragraph, or sentence (English and Chinese punctuation), and each cue is timed by reading speed (15 characters per second by default) or a fixed duration, with a configurable start time and gap.

Timed preview

Press Play to run the subtitle timeline without a video: the current cue is shown as the clock advances, with pause, stop, and loop controls. Use the page-level Fullscreen button to expand the tool for a bigger preview.

Privacy

Everything — parsing, conversion, and editing — runs locally in your browser. No subtitle file is uploaded.