What is GitDiagram?
GitDiagram is a web app and open-source Next.js project by Ahmed Khaleel that turns a GitHub repository into an interactive architecture diagram. An AI model reads the repository's file tree, README and up to 12 source files, writes a short overview, then returns a graph of at most 34 grouped components with labelled connections. Every linked path is checked against the real tree before the graph is compiled to Mermaid, and each component opens its file or folder on GitHub.
Diagrams are stored and shared, so a repository someone has already diagrammed opens instantly. The site also makes narrated explainer videos of about a minute, exports PNG or Mermaid source, offers a Markdown version of every stored diagram at gitdiagram.com/owner/repo.md, and runs a free, read-only remote MCP server at gitdiagram.com/mcp. Private repositories work with a read-only GitHub token.
The repository was created in December 2024, is MIT-licensed and has about 18,700 GitHub stars and 1,430 forks. It publishes no tagged releases; the last commit was on 30 October 2026.
Is GitDiagram worth it?
GitDiagram's value is the zero-step workflow: no clone, no install, no key for most uses, and a shareable link at the end. The pipeline behind it is more careful than the URL trick suggests. One GPT-6 Luna request at low reasoning, according to the architecture docs, streams an overview and a strict graph; the server checks identifiers, connectivity and every linked path against the actual repository, retries invalid output with feedback, and a deterministic compiler, not the model, writes the Mermaid. The browser then sanitises the SVG and allows links only to GitHub. That makes the links trustworthy even when the drawing is not.
The ceiling is built in. The model sees a bounded excerpt of the tree, the README and at most 12 source files, and draws no more than 34 components. For a small library that is plenty; for a monorepo with dozens of services it means a coarse picture in which whole packages collapse into one box, and the project's own guide calls it a map of the important parts, not a complete dependency graph. Very large repositories that GitHub returns as a truncated tree still get a diagram from a partial listing, and an oversized README is rejected outright. A stored diagram also freezes the repository as it was; Regenerate makes a fresh one.
The hosted site's data handling is documented plainly in its privacy policy. Repository content goes to OpenAI, Anthropic and OpenRouter to make what you asked for. Private repositories need a fine-grained token with Contents read-only, or a Continue with GitHub sign-in limited to the repositories you pick; the token sits in an HttpOnly cookie for up to 30 days and is never saved on the server, and private diagrams live in a separate namespace. PostHog session replays run on the site, with typed input masked. The README and the Markdown twin carry paid sponsor slots, CodeRabbit at the time of writing.
The videos are the expensive part and are rationed accordingly. Claude Opus writes the script, Claude Haiku 5.5 designs the scenes, Gemini 3.8 Flash TTS through OpenRouter reads it and whisper-1 times the words; the default caps are one new video per browser and 25 across the site per UTC day, with $3 for one beyond that. Against DeepWiki, which writes a multi-page wiki with a chat, GitDiagram answers a narrower question faster, and a coding agent in your own checkout will draw a more exact diagram of private or uncommitted code.
Where it earns its place
A backend engineer evaluating three open-source job-queue libraries
See how each one is put together before reading any code
Replace 'hub' with 'diagram' in each GitHub URL; stored diagrams open at once and new ones take about a minute. Click a component to jump to its folder. Free within the daily limit; past it, your own OpenAI key pays.
A developer using Claude Code or Codex on a task that touches an unfamiliar dependency
Give the agent the dependency's structure without pasting its source
Add the remote MCP server with one command and ask the agent how the project is structured; it reads the stored overview, components, connections and Mermaid source. Free, rate-limited to 120 tool calls an hour per network by default, and public repositories only.
A developer-relations lead at a 20-person open-source company
Put an architecture picture and a short explainer in the project README
Export the diagram as PNG or copy the Mermaid source as a first draft to edit, and download the explainer video as landscape or 9:16 MP4 with burned-in captions. A video past the free daily allowance costs $3.
Before you commit
- Setup
- Hosted: edit the URL or paste owner/repo on the home page; about a minute for a new diagram. Self-hosted: Bun 1.3.14 and Node 22, bun install, then fill .env with Cloudflare R2 buckets, Upstash Redis, CACHE_KEY_SECRET and an OpenAI or OpenRouter key before bun run dev.
- Integrations
- Remote MCP server (get_repository_diagram, find_repository_diagrams, get_explainer_video) for Claude, Claude Code, Codex, Cursor, VS Code, Gemini CLI, GitHub Copilot CLI and ChatGPT; a Claude Code plugin with a /gitdiagram skill; Markdown at /owner/repo.md; PNG and Mermaid export.
- Data and privacy
- Public diagrams and videos are published to anyone who opens the repository. Repository content goes to OpenAI, Anthropic and OpenRouter. GitHub tokens and OpenAI keys stay in an HttpOnly browser cookie for up to 30 days, never on the server; the suggested token is fine-grained with Contents read-only. PostHog analytics and session replays run on the site. MIT licence.
- Cost at scale
- The hosted site has no subscription. Self-hosting means paying for R2, Upstash and model tokens per diagram; the project does not publish a per-diagram cost, though the app shows an estimate before each run and an optional Fast lane doubles the model price. Videos add Anthropic, OpenAI and OpenRouter calls plus headless Chromium renders.
- Limits
- Code defaults allow 8 server-funded generations per IP an hour (own-key callers are exempt) and 60 calls an hour to the generation endpoints for everyone. Generation has a 300-second budget. Making new videos is in early access, with daily caps. About 55 open issues and pull requests; no tagged releases.
What’s good
- Works from a URL edit; nothing to clone or install
- Every linked path is validated against the real repository
- Deterministic Mermaid compiler and GitHub-only link allowlist
- Free read-only MCP server and Markdown version for agents
What’s not
- At most 12 source files and 34 components, coarse on monorepos
- Stored diagrams go stale until someone regenerates them
- Self-hosting needs Cloudflare R2, Upstash Redis and a model key
- Sponsor placements in the README and Markdown output
Best for
Engineers sizing up an unfamiliar GitHub repository, and agents that need a quick structural summary of a public one, before anyone opens the code.
GitDiagram alternatives
GitDiagram: common questions
- Is GitDiagram worth it?
- GitDiagram gives you a decent first map of an unfamiliar repository in the time it takes to edit a URL, as long as you treat it as a sketch rather than a blueprint. We rate it 4.0 out of 5.
- How much does GitDiagram cost?
- Free to use and open source (MIT). New diagrams are free within a daily limit, then need your own OpenAI API key; explainer videos past the free daily allowance cost $3 each.
- What are the downsides of GitDiagram?
- At most 12 source files and 34 components, coarse on monorepos; stored diagrams go stale until someone regenerates them; self-hosting needs Cloudflare R2, Upstash Redis and a model key; sponsor placements in the README and Markdown output.
- Who is GitDiagram best for?
- Engineers sizing up an unfamiliar GitHub repository, and agents that need a quick structural summary of a public one, before anyone opens the code.
- How much does GitDiagram cost for a team or in production?
- The hosted site has no subscription. Self-hosting means paying for R2, Upstash and model tokens per diagram; the project does not publish a per-diagram cost, though the app shows an estimate before each run and an optional Fast lane doubles the model price. Videos add Anthropic, OpenAI and OpenRouter calls plus headless Chromium renders.
- Is GitDiagram safe for company data?
- Public diagrams and videos are published to anyone who opens the repository. Repository content goes to OpenAI, Anthropic and OpenRouter. GitHub tokens and OpenAI keys stay in an HttpOnly browser cookie for up to 30 days, never on the server; the suggested token is fine-grained with Contents read-only. PostHog analytics and session replays run on the site. MIT licence.
- What are the best GitDiagram alternatives?
- The closest alternatives we have reviewed are OpenWiki, Archify and Repomix.
Answers checked Oct 31, 2026.
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