Let’s be honest: Grammarly is a deep, cloud-based grammar and writing assistant — and for exhaustive grammar checking across every device it’s still excellent. Shadowtype is a different thing. If what you want is private, local, free and open-source inline writing help — predictive ghost-text completion plus on-device rewrite — without sending your text to the cloud, paying monthly, or signing in, this is the alternative for you. It is not a full replacement for Grammarly’s grammar engine or its cross-platform reach, and we’ll say exactly where Grammarly still wins.
Two different categories. Shadowtype wins on privacy, offline use, true inline completion, and being free and open source. Grammarly wins on deep grammar checking and cross-platform reach — and we mark those rows plainly.
| Capability | Shadowtype | Grammarly |
|---|---|---|
| Inline ghost-text autocomplete | Yes | Deprecated |
| Works fully offline | Yes | No |
| Text stays on device | Yes | Cloud-processed |
| No account required | Yes | Sign-in required |
| On-device selection rewrite | Yes | Cloud |
| Local API + MCP server (OpenAI-compatible) | Yes | No · cloud-only |
| Deep grammar & style checking | Basic | Yes |
| Cross-platform (Win / iOS / Android / web) | Mac only | Yes |
| Pricing | Free & open source | $30 / mo · ~$144 / yr |
Shadowtype runs 100% on-device with llama.cpp and Metal. Your keystrokes are never uploaded, there’s zero telemetry, and no account. Grammarly, by default, sends your text to the cloud for analysis and requires sign-in.
Free and open source — versus Grammarly Pro at $30/month, roughly $144/year, recurring for as long as you use it. No bill, ever.
Shadowtype predicts your next words as ghost text in any app — Tab accepts a word, ⌥Tab a whole line — plus on-device selection rewrite with ⌥⌘K (improve, shorten, formal, casual, fix grammar, summarize). Grammarly deprecated inline autocomplete and works reactively instead.
An OpenAI-compatible HTTP endpoint runs on 127.0.0.1 so your scripts, editors, and agents can call the same on-device model — no key, no cloud. A built-in MCP bridge plugs into Claude Code and other MCP clients, and the BYOM picker loads any GGUF.
127.0.0.1 with no key required, so your terminal, editor plugins, and AI agents can call /v1/chat/completions against the same on-device model. A built-in MCP server plugs into Claude Code and other MCP clients, and the BYOM picker loads any GGUF you drop in. Everything is bound to localhost — nothing leaves your Mac. Grammarly is cloud-based and offers no local API or MCP server.Download Shadowtype free, accept your first word with Tab, and upgrade once — never monthly, never to the cloud.