How can I build a mobile-friendly app that blocks spoilers?

Spoiler detection is probably harder than the interface. You need to decide which content counts as a spoiler, how long the protection should last, and how to handle vague references, images, videos, and intentionally misspelled names. Start with a small, controlled use case—such as hiding posts containing selected titles—before trying to support the entire web.

A normal website generally can’t read or modify pages opened on other websites because of browser security restrictions. To scan and hide content across sites, you’d normally need a browser extension, a custom browser, or an app that loads pages through its own interface. Mobile support may be limited depending on the browser and operating system.

The first major design question is how you’ll define a spoiler. You could begin with a simple keyword and title filter: let users enter the movies, shows, games, or books they want to avoid, then hide text containing related terms. Blocking entire sites is easier, but it also removes harmless content and won’t work well for every platform.

A more advanced version could inspect the text of a page and use a language model to classify possible spoilers, but that would be expensive and slower than keyword matching. A practical beginner project would start with a browser extension that scans visible text, replaces matching sections with a warning, and lets users reveal them manually. Later, you could add a user-provided model or API for more context-aware detection.