Lexithm is a free, alternative to Sourcegraph that lets you understand any GitHub repository in seconds — no CLI, no setup, no signup required. Paste a GitHub URL and immediately ask questions about the codebase in plain English. Lexithm clones the repo, indexes every file, builds a dependency graph, and lets you chat with the entire codebase like a senior dev who already read everything. Key features: AI Codebase Q&A — Ask "where is the auth logic?" or "explain the data model" in natural language File browser — Explore any repo with a collapsible tree + syntax-highlighted viewer Dependency graphs — Visualize how modules connect Semantic search — Find code by meaning, not just keywords Built for solo devs, open-source maintainers, and anyone who needs to onboard into a new codebase fast.