Capsule — Single-file web apps that save their data into SQLite. It was shared on Show HN in 2026 and received 380 upvotes on Hacker News. Capsule keeps your tools and data inside a single .capsule file, with no servers to manage and no monthly fees. A canonical URL here once pointed all of /templates/* at the homepage, telling Google they were duplicates of it. Opening a file works immediately on desktop or via Capsule Web. Every note, checklist, or calculation you save is written directly into the file. There are no tracking scripts, no cloud databases, and no accounts. Because apps run locally, you can use them on a flight, on a train, or completely offline. When you share a file, you send the data and the interface together. 🛡️ Sandboxed Security Untrusted document code runs inside an isolated webview with a strict Content Security Policy. Apps cannot access your local files or make unauthorized network connections. 🗄️ Standard SQLite Format Data is stored in standard SQLite tables inside the file. 🔄 Safe Sync and Conflict Merging Writes are batched into atomic transactions so files stay intact across Dropbox, iCloud, or OneDrive. Your device ✦ Life.capsule 0 items · 1.2 MB 03 / CROSS-PLATFORM One file across every operating system Capsule files are completely cross-platform by default. Your apps launch with full desktop performance on any computer, with native iOS and Android support coming soon. Introducing it on Hacker News, the author wrote: "Hey HN, I always had the problem that building HTML pages is really simple now, but trying to save data required hosting it somewhere, and sharing it afterwards was not easy. Over the last few months, I've been building an app called Capsule (it’s also the file extension name) written in Rust with Tauri 2.0 that allows packing an HTML app and its data into a single SQLite file."