Drag a large text/json text file and start exploring it with regular expressions and searches in realtime and with a smooth UI.
Use it and try it here: https://jsilveira.github.io/text-explorer/text-explorer.htm dragging your JSON file*
.json files are parsed as JSON (as one large array of strings or objects where values are the strings), any other kind of file is splitted and read line by line.
Everything runs in the client, a Google Chrome page. It loads the file in a separate service worker, and all the searches and processing runs there without blocking the UI. Searches on large files have instant feedback on a smaller subset of documents so you can create and tweak your regular expression without waiting for the full search on the whole data set. The data never leaves your browser, nothing is uploaded.
The only limit in file size is Chrome's memory. It will let you know when it's too big, by smoothly crashing. A modern laptop should handle at least 100mb of text with ease.
Host folder in any kind of static http server (for example, if you load the project in an IDE such as Webstorm and right-click text-explorer.htm and then 'Open in browser')