About
About SubAlign
SubAlign is a free collection of subtitle tools that run entirely in your browser. No uploads, no accounts, no waiting; just open a file, fix it, and download the result.
Why we built it
Fixing a subtitle file is usually a small job. Shift the timing a few seconds, convert SRT to VTT, repair some garbled accents. Yet the typical options are clunky desktop apps or sketchy "upload your file" websites that send your data to a server you know nothing about. We thought a faster, more private approach was possible, so we built one.
Modern browsers are powerful enough to do all of this work locally. SubAlign takes advantage of that. The processing happens on your own device, instantly, and your files never touch a server.
Privacy by design
This is the core principle behind everything here: your files never leave your device. There is no backend, no database and no file upload. When you use a tool, the entire operation runs in JavaScript inside your browser tab. Close the tab and the data is gone. It is private because it is technically incapable of being anything else.
What you can do here
- Auto-Sync to Reference · Automatically retime a subtitle to match a correctly-synced one.
- Subtitle Editor · Edit subtitle text and timings cue by cue, then export any format.
- Add Subtitles to Video · Play your video with any subtitle file and fix the sync live.
- Subtitle Converter · Convert between SRT, VTT, ASS/SSA, SBV, SUB, SMI, LRC and TTML.
- Text to SRT Generator · Turn a plain-text transcript or script into a timed SRT file.
- Frame Rate Converter · Rescale timings between frame rates to fix subtitles that drift.
- Encoding Repair · Fix garbled subtitle characters by re-decoding them to UTF-8.
- Merge & Split · Combine two SRT files into one, or split one file in two.
- Cleanup Tools · Remove SDH/hearing-impaired tags, strip formatting, check CPS.
- Subtitle to Text · Strip timecodes to get a clean transcript from any subtitle file.
Free, and built to stay that way
SubAlign is free to use. Because everything runs in your browser, there are no server costs to pass on, which keeps the tools fast and the model simple. The site is supported by unobtrusive advertising so it can stay free for everyone.
Who's behind it
SubAlign is built and maintained by Paarth Sonkiya, an independent software developer. It is a small, hands-on project, and the same person who writes the parsing code answers the contact emails. Every tool is tested against real subtitle files, the messy kind with overlapping cues, broken encodings and mixed line endings, because that is what people actually have.
Have feedback?
We are always improving the toolkit and adding new features. If you have run into a bug, have a subtitle format that does not convert cleanly, or want a tool that does not exist yet, we would genuinely like to hear it. Head to the contact page to get in touch.