Subtitle Format Converter
Convert subtitles between SRT, VTT, ASS/SSA and plain text — free, instant, nothing uploaded
The input format is detected automatically from the file's content, not just its extension.
100% private — Files are converted right in your browser and never uploaded to any server.
How it works
- 1
Drop in a subtitle file — SRT, VTT, ASS or SSA.
- 2
Pick the output format you need.
- 3
Click convert and download the result.
Subtitle formats differ mostly in time syntax
Format detected from content
The input format is sniffed from actual file markers — a WEBVTT header, an ASS [Script Info] block — not from the file extension, which some video platforms serve incorrectly.
SRT, VTT and ASS/SSA round-trip
SubRip, WebVTT and SubStation Alpha files convert into any of the four output choices, including a plain-text TXT transcript — useful when a translation workflow only needs the spoken lines.
Cue timings stay intact
Start and end timestamps carry across every conversion, so subtitles stay in sync with the video after switching formats. Files are read and written as UTF-8, preserving accented subtitles.
Frequently asked questions
How is the input format detected?⌄
By reading the file's actual content — a WEBVTT header, ASS/SSA's [Script Info] section, or plain SubRip numbering and timestamps — not just the file extension, so a mislabeled file still converts correctly.
Will I lose any timing precision converting to ASS/SSA?⌄
ASS timestamps use centiseconds (hundredths of a second) instead of SRT/VTT's milliseconds, so times are rounded to the nearest 10ms. This is invisible in playback.
Is anything uploaded to your servers?⌄
No — parsing and conversion both happen entirely in your browser. The file never leaves your device.
Related tools
What Is a Subtitle Format Converter?
A subtitle format converter translates caption files between the formats that video platforms and players actually use: SubRip (.srt), WebVTT (.vtt), SubStation Alpha (.ass/.ssa), and plain text (.txt). Different tools accept different formats — YouTube, Vimeo, and most course platforms expect SRT or VTT, while players like VLC happily load ASS, and a translation workflow may need a plain-text transcript. This tool detects the input format from the file's content rather than trusting the extension, converts the cues while keeping their timings intact, and hands you a ready-to-download file. It is built for video editors, translators, content creators, and subtitle hobbyists.
What this tool can do
- ✅ Convert between SRT, WebVTT, ASS/SSA, and plain text
- ✅ Detect the source format by reading the file's actual content
- ✅ Preserve every cue's start and end timings across conversions
- ✅ Export a plain-text transcript from any subtitle file
- ✅ Run instantly in your browser — nothing is uploaded
When you would use it
- 🎬 Uploading subtitles to YouTube or a course platform that requires SRT or VTT
- 📺 Converting a styled ASS fansub into a simple SRT for a standard player
- 📝 Producing a plain-text transcript for translation or search
- 💾 Backing up captions in a neutral format that any tool can read
The whole conversion happens locally in your browser, so your subtitle file never leaves your device. Keep in mind that timings are preserved, but visual styling — colors, fonts, positioning, and effects found in ASS files — is dropped when converting to SRT, VTT, or TXT, which are plain-timing formats. Plain text is an output-only format, since it carries no timing information to convert from.