About SubToolbox

SubToolbox exists because subtitle tools have a trust problem. Your captions belong with your video — often someone else's footage, a client's cut, an unreleased film — and shipping them to a random web server to have them reformatted is a leap most people take only because they think they have to. You don't. Every format conversion, sync fix, merge and repair here runs in your browser with JavaScript; the file is read into memory, transformed, and handed back. There is no upload step to secure because there is no upload.

The second conviction is honesty about limits. Converting ASS to SRT loses styling — because SRT has no styling — so the pages say so before you convert. Auto-timing a transcript produces an estimate, not a sync — so the pages call it a draft. No page on this site promises translation, transcription, subtitle extraction from video, or burning captions into pixels, because a text tool cannot do those things, and tools that imply otherwise waste your afternoon.

What you get instead is the mechanical half of subtitling done properly: formats that convert without drift, timings that move only when you move them, a cue table that shows problems before players do, and repairs that fix overlaps and tags without touching anything else. The creative half — what to say, and when the words are actually spoken — stays with you, where it belongs.

The site is free, needs no account, and works offline once loaded. If a conversion surprises you, the contact page is one click away.