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SubAlign
SubAlign

Subtitle Format Converter

Convert subtitles between SRT, WebVTT and ASS/SSA. Drop a file in, pick a target format, and download the result, all in your browser.

100% private. Your files are processed locally in your browser and never uploaded to a server.

Drop a subtitle file

or click to browse · SRT, VTT, ASS/SSA

What this tool does

This converter changes a subtitle file from one format to another, for example from SRT to VTT, VTT to SRT, or to and from ASS/SSA. It reads the timings and text of every cue and rewrites them using the target format's conventions: SRT uses comma decimals (00:00:01,000), WebVTT uses period decimals and a WEBVTT header, and ASS uses centisecond timing inside a styled events section.

When you'd use it

About lossless vs. lossy conversion

Timing and text always convert exactly. Where a target format can't represent something, such as ASS positioning and styling tags when converting to SRT, those extras are stripped and the tool tells you. Converting into ASS applies a clean default style.

Is my file uploaded anywhere?

No. The conversion runs entirely in your browser using JavaScript. Your subtitle file is never sent to a server.

Frequently asked questions

How do I convert an SRT file to VTT?

Drop your .srt file into the converter, choose WebVTT (.vtt) as the target format, and click download. The timings are rewritten with the period decimals and WEBVTT header that VTT requires, all in your browser.

Can I convert VTT to SRT?

Yes. Upload a .vtt file, select SubRip (.srt) as the target format, and download. SubAlign converts the timestamps from period to comma decimals automatically.

Does converting subtitles lose any text or styling?

Timing and text always convert exactly. Advanced ASS/SSA styling and positioning that SRT and VTT cannot represent is stripped, and the tool tells you what was dropped.

Are my subtitle files uploaded to a server?

No. The format conversion runs entirely on your device using JavaScript. Your files never leave your browser.

More subtitle tools

Offset Shifter Move every subtitle earlier or later by a set number of seconds. Framerate Converter Fix PAL/NTSC speed drift by rescaling timings between frame rates. Encoding Repair Repair garbled accents and mojibake by re-decoding to UTF-8. Merge & Split Join multi-part subtitles or split one file in two. Cleanup Tools Strip SDH tags, remove formatting, and check reading speed (CPS).