Subtitle Editor

Subtitle Editor - Edit SRT & VTT Files Online

Subtitle Editor opens, edits, and converts SRT and VTT subtitle files entirely in your browser — no upload, no account, no watermark. Adjust timing with millisecond precision, merge or split entries, shift the whole track ±0.1 to ±60 seconds to fix sync drift, search-and-replace text across hundreds of lines, and convert between SRT (universal player support) and WebVTT (HTML5 video) with one click. Built for content creators fixing fan-translated subs for YouTube uploads, podcasters generating accessibility captions, language learners polishing subtitle translations, video editors syncing dialog to a re-cut, and accessibility professionals adding closed captions for compliance with WCAG and ADA requirements. Supports drag-and-drop, undo/redo, and instant download of the edited file.

What is a Subtitle Editor?

A subtitle editor is a tool for creating and modifying subtitle files. This editor supports:

- SRT (SubRip) - Most common format
- VTT (WebVTT) - Web standard format

You can edit timing, text content, merge entries, split entries, and shift all timestamps. Perfect for syncing subtitles or fixing timing issues.

How do I use this tool?

Using the Subtitle Editor:

1. Load a subtitle file (SRT or VTT) or create a new one
2. Edit entries in the table:
- Modify start/end times
- Edit subtitle text
- Add or delete entries
3. Use toolbar actions:
- Shift Times: Move all timestamps
- Merge: Combine selected entries
- Split: Divide one entry into two
4. Export as SRT or VTT format

All changes are made in real-time in the table.

What is the difference between SRT and VTT?

SRT (SubRip Subtitle):
- Most widely supported format
- Simple text-based format
- Uses comma for milliseconds (00:00:00,000)
- Works with most video players

VTT (WebVTT):
- Web standard for HTML5 video
- Supports styling and positioning
- Uses period for milliseconds (00:00:00.000)
- Required for web video players

Both formats contain the same basic information: timing and text.

How do I sync subtitles?

To sync subtitles with video:

1. Find an entry that's out of sync
2. Note how many seconds off it is
3. Use 'Shift Times' to adjust:
- Positive value: Delays subtitles
- Negative value: Makes subtitles earlier
4. Apply to all or selected entries

For example, if subtitles appear 2 seconds too early, shift by +2 seconds.

Can I merge multiple subtitles?

Yes! To merge subtitle entries:

1. Select the entries you want to merge (use checkboxes)
2. Click 'Merge' in the toolbar
3. The entries will combine into one:
- Start time from first entry
- End time from last entry
- Text combined with line breaks

This is useful for combining short entries into longer ones.

Is my data safe?

Yes, completely safe:

- All processing happens in your browser
- No files are uploaded to any server
- Your subtitles never leave your device
- No data is stored or tracked

This is a 100% client-side tool. You can even use it offline after the page loads.

How precise is the millisecond timing in SRT and VTT files?

SRT timestamps use HH:MM:SS,mmm where mmm is 0-999 milliseconds; WebVTT uses HH:MM:SS.mmm with the same resolution. Both formats are accurate to 1 ms in theory, but real-world playback precision depends on the video player and frame rate. At 24 fps a single frame is 41.6 ms wide, at 30 fps it's 33.3 ms, at 60 fps it's 16.7 ms — so timing finer than one frame interval is imperceptible to viewers. The editor stores times internally as floating-point seconds and rounds only on export, so repeated shift operations don't accumulate rounding error. For broadcast-grade workflows that need frame-accurate sync, use SMPTE timecode and tools like Subtitle Edit or EZTitles instead — SRT and VTT are designed for streaming and web video where 1-frame slop is acceptable.

When should I use SRT versus WebVTT for my subtitle file?

Use SRT when you need maximum compatibility: it works in VLC, MPC-HC, mpv, MX Player, Plex, Jellyfin, every smart-TV media player, every desktop video player, and is the format YouTube, Vimeo, and Facebook accept for uploaded captions. Use WebVTT when you're embedding HTML5 <video> elements directly on a website — VTT is the only format the <track> element natively supports, and it allows CSS styling, positioning cues (line:0 align:start), karaoke-style timing, and chapter markers that SRT cannot represent. Both encode UTF-8 text, support multi-line entries, and store the same start/end timestamps. For most use cases SRT is the default; convert to VTT only when targeting a specific HTML5 player or browser-based video API that requires it.

Key Features

• Edit SRT and VTT subtitle files
• Modify start and end times
• Edit subtitle text with multi-line support
• Add, delete, and insert entries
• Shift all timestamps at once
• Merge multiple entries into one
• Split entries into two
• Renumber entries automatically
• Convert between SRT and VTT formats
• Preview output before download
• Copy to clipboard
• 100% client-side processing
• No file upload required
• Dark mode support
• Mobile-friendly interface