About Subtitle Toolkit

Subtitle Toolkit is a small set of free utilities for people who work with subtitle and caption files: video editors, translators, podcast producers, accessibility specialists and anyone handed a .srt that won’t load.

Why it runs in your browser

Subtitle files are frequently confidential. An unreleased product demo, a client interview, a medical lecture or a legal deposition can all arrive as a caption file. Uploading those to an unknown server to change a comma into a period is a bad trade.

Every tool here is plain JavaScript that executes on your own device. There is no upload endpoint, no queue, no storage and no account. You can load a page, disconnect from the internet, and the tool will still work.

How the site is funded

The tools are free and have no usage limits. The site is supported by advertising, which is why you may see ads on the page. Ads are never placed inside the tool interface, and no subtitle content is ever shared with advertisers — the content never leaves your browser in the first place.

Accuracy and limitations

These tools perform deterministic text and timestamp transformations. They do not rewrite, translate or “improve” your text, because automated rewriting of captions risks changing meaning. Where a transformation could be lossy — such as discarding WebVTT cue settings when converting to SRT — it is documented on the relevant tool page.

Related project

For finding the tools that produce these files — transcription, captioning and translation services — see the AI tool directory.

Last updated 2026-09-21.