Subtitle Searcher & Downloader for Youtube is a free Chrome add-on developed by autosubtitle.service. This handy tool automatically downloads and stores subtitles when you watch YouTube videos, making it easy to search for words in the subtitles across a wide range of videos.

Once installed, the extension will automatically download the subtitles of the videos you watch on YouTube and save them to your browser's local storage. To search for subtitles using keywords, simply click on the Puzzle piece icon on the right side of your browser's address bar to pin the extension. Then, click on the extension icon to open the search page and enter your keywords in the search box.

On the search results page, you can click on the language button to download the subtitle file. Alternatively, you can click on the time code to open a new tab and start playing the video from the specified time, or click on the text content to play the video from the specified time directly on the search result card.

It's important to note that when your hard-disk space is insufficient, the browser may automatically erase all downloaded subtitle data, so make sure to keep an eye on your storage capacity.