GitDiagram vs DeepWiki: one diagram or a whole wiki
Written by GitDiagram. Facts about DeepWiki checked against its own docs on (sources).
DeepWiki and GitDiagram both start from a public GitHub URL and need nothing installed, but they make different things. DeepWiki writes a wiki about the repository: dozens of pages of explanation with many diagrams, plus a chat (Ask Devin) that answers questions. GitDiagram draws one interactive diagram of the whole repository, with every part linked to its code. Choose DeepWiki to read about a project in depth or ask it questions; choose GitDiagram for the whole system on one screen, a link to share, or Mermaid code for your README. They work well together.
Which to choose
| Choose DeepWiki when | Choose GitDiagram when |
|---|---|
| You want written explanations of each part of the project. | You want the whole architecture on one screen in a few seconds. |
| You want to ask questions about the code in a chat. | You want to click a part and land on its file or folder on GitHub. |
| You want sequence or class diagrams of specific flows. | You want Mermaid code or a PNG to put in your own docs. |
| Your team already uses Devin and wants wikis of its private repositories. | You want a private repository's diagram without signing up for anything. |
| You want a tool that is open source. |
The same repository in both
For Express (expressjs/express), DeepWiki's wiki has 33 pages in 9 sections, about 40,000 words, with 151 Mermaid diagrams (flowcharts, sequence diagrams and class diagrams). We counted them on 2026-11-09 through DeepWiki's own MCP server (read_wiki_structure and read_wiki_contents). Its FastAPI wiki has 56 pages.
GitDiagram's Express diagram is one picture: 16 components in 5 groups (Application Entry, Routing Pipeline, HTTP Semantics, Rendering Delivery, Framework Internals) with 21 labeled connections, such as Express Application to Router Integration, "dispatches request". A one-paragraph overview sits above it, and the page lists every component and connection as text.
So DeepWiki answers "how does each part work?", and GitDiagram answers "what are the parts and how do they connect?".
What DeepWiki does
DeepWiki, made by Cognition (the company behind Devin), indexes a repository and produces a wiki with architecture diagrams, links to sources and summaries. Replace github.com with deepwiki.com in a repository URL; Cognition says more than 50,000 popular public repositories are already indexed, and any other public repository can be added for free.
It is the free public version of Devin's own wiki and search. Private repositories need a Devin account. A .devin/wiki.json file in a repository can steer what the wiki covers, and DeepWiki's docs note that on large repositories its automatic page planning can leave out some folders.
For agents, DeepWiki runs a free MCP server at https://mcp.deepwiki.com/mcp with no sign-in, for public repositories, with the tools read_wiki_structure, read_wiki_contents and ask_question.
What GitDiagram does
Replace hub with diagram in a GitHub URL. A stored diagram opens at once; otherwise one is made in about a minute and kept for the next visitor. You can pan and zoom, read the overview, export a PNG or copy the Mermaid code.
GitDiagram's limits: it is a map of the important parts, not a complete dependency graph. It can simplify or leave things out, it works only with GitHub repositories, and it shows the repository as it was when the diagram was made (Regenerate makes a fresh one).
At a glance
| Question | GitDiagram | DeepWiki |
|---|---|---|
| What you get | One interactive architecture diagram: up to 34 main components in groups, with labeled connections and a written overview. Each component links to its file or folder on GitHub. | A multi-page wiki with diagrams and source links, and a chat that answers questions about the code. |
| Setup | None. Replace hub with diagram in a GitHub URL, or paste the URL on the home page. | None for public repositories: replace github.com with deepwiki.com. |
| Private repositories | Yes, with a fine-grained GitHub token that stays in your browser and is never saved on GitDiagram's servers. | Yes, through a Devin account with the repository connected. |
| Price | Free. Making new diagrams is free within a shared daily limit; after that you can add your own OpenAI API key. | Free for public repositories. Devin plans are listed at $0 (Free), $20 a month (Pro), $200 a month (Max) and $80 a month plus $40 per seat (Teams). |
| Open source | Yes, MIT (source). | Not that we found: it is a hosted Cognition product. |
| For AI agents | Markdown at gitdiagram.com/{owner}/{repo}.md and a free MCP server at https://gitdiagram.com/mcp, no sign-in. | A free MCP server at https://mcp.deepwiki.com/mcp, no sign-in. |
Questions
Is DeepWiki free?
Yes for public repositories: reading wikis and asking questions needs no account. Wikis of private repositories come with a Devin account; Devin has a free plan and paid plans from $20 a month.
Which is better for understanding a new repository?
Start with GitDiagram to see the main parts and how they connect, then read DeepWiki's pages or ask its chat about the parts you care about. The diagram takes seconds to read; the wiki goes much deeper.
Can an AI agent use both?
Yes. Both have free MCP servers with no sign-in: https://mcp.deepwiki.com/mcp for DeepWiki and https://gitdiagram.com/mcp for GitDiagram, whose diagrams are also plain Markdown at gitdiagram.com/{owner}/{repo}.md.
Sources
Checked on . Products change: if something here is out of date, open an issue.