What is Skim?

Skim is a free, open-source (MIT) email client for Windows that strips away everything you don't need. Built on a native Rust core with Tauri 2, it delivers a ~5 MB installer, sub-second cold starts, and instant full-text search. No calendar, no rules engine, no bloat — just email, done fast. It's local-first, works offline, and sends zero telemetry. The AI assistant is optional and runs on your own API key.

Who it's for

• Minimalists who want an email client that stays out of their way, with fewer buttons and zero cognitive load
• Privacy-conscious users who insist on local-first software with no telemetry, no subscriptions, and no third-party proxies
• Power users who want instant full-text search across their entire mailbox and a hotkey-driven interface for speed

Key features

Native Rust core with instant performance

Skim runs on a Rust core with a system WebView2 UI — no bundled browser like Electron. The installer is a few megabytes, cold start is instant, and idle memory is modest. It installs without admin rights and works offline, syncing mail over IMAP into a local SQLite database with FTS5-powered search.

AI on your terms with BYOK

Paste your own Anthropic (Claude) or OpenRouter key (Claude, GPT, Gemini, Grok, and hundreds more) and the AI features come alive. Requests go straight from your machine to the provider — no proxy, no markup. The key lives in Windows Credential Manager. No key? Skim still works as a fast email client.

Drafts in your voice and smart recaps

Skim can analyze up to a hundred of your sent messages and write the way you write — same greetings, sentence length, punctuation. It replies in the sender's language, even one you don't speak. The AI recap of your unread digests up to 20 emails, highlighting what needs a reply first with deadlines and cited sources.