Fairy Lantern

Checks the page you are on for hidden instructions aimed at AI assistants, and shows what they try to make the assistant do.

Some web pages hide instructions that are not meant for you. They are meant for the AI assistant you might ask to read or summarize the page. This is called a prompt injection: a line of invisible text, an HTML comment or an encoded passage tells the assistant to ignore its instructions, send your data somewhere else, or recommend something. Fairy Lantern shows you these traps before you hand a page to an assistant. What it does - Click the lantern in your toolbar to check the page you are on. - A window lists each suspicious passage: its severity, what it seems to attempt, where it is hidden, the addresses it mentions and an extract. - If the page looks trapped, the extension advises you not to have it read by an AI assistant. - The lantern keeps a mark in the toolbar for that page: the number of passages found, in red or orange. It only looks when you ask By default, the analysis runs in your browser, and only when you click the icon. The extension uses the activeTab and scripting permissions: it has no access to any site outside that click, and it does not run in the background on your pages. Automatic analysis, if you want it On the welcome page, you can turn on "Analyse every page automatically". It is off by default. Chrome then asks for access to the sites you visit, and you can turn it off at any time in the options, which gives that access back. With the option on, each page is analysed in your browser as soon as it has loaded, in small steps so that the page does not freeze. A page with a probable trap is replaced by a warning that lists every passage found, with its severity, what it tries to do, how it is hidden and the address it sends to. You can go back, or open the page anyway. Pages with only suspicious passages simply light up the lantern. Sharing is optional You can choose to share the traps you find to help build a list of trapped pages. The box is unticked by default, and you can change your choice at any time in the extension options. With your agreement, a report contains only the site, the page path without anything after ? or #, the suspicious passages, the extension version and the language. Without your agreement, nothing is sent. A clean result is not a guarantee: the extension sees what your browser sees, and a site can still show its traps to robots only.