Missing README. Undocumented internal API. A function whose comments last matched the code four refactors ago. AI documentation tools read source and produce docstrings, READMEs, and inline explanations that stay honest to what the code does today. The seven picks below cover VS Code and JetBrains extensions, standalone editors, and terminal tools that run against local or hosted models.
What to look for in an AI docs tool
The right pick depends on how much of the doc work you want automated and where the model runs. A few points to weigh:
- Model location. Cloud-only (OpenAI, Anthropic API) is faster and smarter but sends code to a third party. Local models keep the code on your machine.
- Docstring vs full README. Some tools inline docstrings; others draft site-wide documentation.
- Editor integration. VS Code and JetBrains extensions blend into your existing flow. Standalone tools work outside an editor and against any repo.
- Language coverage. Python, JavaScript, and Go are universally supported. Older languages (COBOL, Fortran) or newer ones (Zig, Gleam) drop off fast.
- Update flow. Regenerating docs after a refactor without wiping your custom edits is the feature that separates hobby tools from production ones.
Quick comparison
| App | Best for | Editor | Free plan | Paid | Local model |
|---|---|---|---|---|---|
| Mintlify Writer | VS Code docstrings | VS Code, JetBrains | Free (personal) | Team plan | No |
| Swimm | Team-owned documentation | VS Code, JetBrains | Free (small teams) | Enterprise | No |
| DocuWriter.ai | One-shot README generation | Web, VS Code | Free credits | Subscription | No |
| Continue.dev | Local model in the editor | VS Code, JetBrains | Full free | None | Yes |
| Aider | Terminal-native pair programming | Terminal | Free (open source) | Model costs | Yes |
| Cursor | Full editor with doc generation | Cursor | Free tier | Subscription | Partial |
| GitHub Copilot | Line-by-line comments | VS Code, JetBrains, Neovim | Free (limited) | Subscription | No |
1. Mintlify Writer, best VS Code docstring pick
Mintlify Writer is a VS Code and JetBrains extension that generates docstrings on demand. Highlight a function, press the shortcut, get a JSDoc/PyDoc/rustdoc block that describes parameters, return type, and behaviour based on the actual code.
The reason to pick it is that the shipped docstrings usually pass code review without much editing. Mintlify’s separate hosted docs product (mintlify.com) is where the same team ships a full docs-as-code publishing platform.
Where it falls short: Free tier is generous for individuals; team features live behind a paid plan. Code is sent to the Mintlify API.
Pricing: Free for personal use. Team plans priced per seat.
Platforms: VS Code, JetBrains IDEs (Windows, macOS, Linux).
Download: mintlify.com · Marketplace
Bottom line: The default in-editor docstring pick.
2. Swimm, best for team-owned docs
Swimm takes a different angle: documentation lives in the repo as markdown, tied to snippets of source. When code changes, Swimm flags docs that reference the changed lines and offers AI-drafted updates. It integrates with GitHub Actions to block PRs that leave docs stale.
The reason to pick it is if documentation drift is the actual problem, not “no docs at all”. Small startups skip it. Mid-sized codebases with turnover benefit.
Where it falls short: Setup overhead is real. You are adopting a documentation workflow, not just a generator.
Pricing: Free for small teams. Enterprise plans available.
Platforms: VS Code, JetBrains IDEs (Windows, macOS, Linux). GitHub Actions.
Download: swimm.io
Bottom line: The pick when the problem is “docs go stale”, not “no docs exist”.
3. DocuWriter.ai, best one-shot README
DocuWriter.ai points at a folder or a GitHub repo and drafts a README, an API reference, or unit tests. It works well when you inherit a codebase with no documentation and need a first pass.
Everything runs in the browser or a VS Code extension. Free credits cover a small project; larger repos need a subscription.
Where it falls short: Not built for continuous doc maintenance. Best used once per repo, then curated by hand.
Pricing: Free trial credits. Monthly subscription tiers.
Platforms: Web, VS Code (Windows, macOS, Linux).
Download: docuwriter.ai
Bottom line: The pick when you need a first-pass README today and will curate it tomorrow.
4. Continue.dev, best local model option
Continue.dev is an open-source VS Code and JetBrains extension that connects to any LLM: OpenAI, Anthropic, or a local Ollama or LM Studio instance. It handles inline completion, chat, and doc generation without sending code to a hosted service.
The reason to pick it is that documentation prompts run against your local model. XDA’s story of a local LLM reconstructing deleted project docs is exactly the workflow Continue targets.
Where it falls short: Quality is bounded by the local model. Small quantised models produce weaker docstrings than GPT-4-class hosted models.
Pricing: Free and open source (Apache 2.0). You pay only for model tokens if you use a hosted provider.
Platforms: VS Code, JetBrains IDEs (Windows, macOS, Linux).
Download: continue.dev · GitHub
Bottom line: The default when the code cannot leave your machine.
5. Aider, best terminal-native option
Aider is a command-line AI pair programmer that runs against OpenAI, Anthropic, or local models via LiteLLM. Point it at a repo, ask for docs, and it edits files in place with a git commit per change. Rollback is a git revert.
The terminal interface is the reason to pick it. If your editor is Neovim, Emacs, or nothing at all, Aider gives you the same code understanding a VS Code extension does.
Where it falls short: No GUI. Requires comfort with the command line and git.
Pricing: Free and open source (Apache 2.0). Token costs go to your chosen model provider.
Platforms: Terminal (Windows via WSL, macOS, Linux).
Download: aider.chat · GitHub
Bottom line: The pick for terminal-first workflows.
6. Cursor, best full-editor pick
Cursor is a fork of VS Code with AI features baked in: chat, inline edits, agent mode, and documentation generation across the whole workspace. It supports multi-file rewrites and can regenerate docs after a refactor with one prompt.
Free tier gives limited requests per month. Paid tier unlocks larger context windows and priority routing to frontier models.
Where it falls short: It replaces your editor. If you have deep VS Code extension setup, migration is real work.
Pricing: Free tier with request cap. Paid subscription.
Platforms: Windows, macOS, Linux.
Download: cursor.com
Bottom line: The pick when you are willing to switch editors for the AI features.
7. GitHub Copilot, best inline comment generator
GitHub Copilot does line-by-line inline suggestions in VS Code, JetBrains, Neovim, and Visual Studio. For documentation specifically, typing /// or """ above a function usually triggers a full docstring inline. Copilot Chat handles README drafts and multi-file explanations.
The reason to pick Copilot is that it is the least intrusive option. It sits in your editor and helps when you invite it.
Where it falls short: Not documentation-first. It is a general assistant that does docs among many other things. Free tier is limited; individuals and teams pay monthly.
Pricing: Free tier for individual open-source use. Paid Individual and Business plans.
Platforms: VS Code, JetBrains IDEs, Neovim, Visual Studio (Windows, macOS, Linux).
Download: github.com/features/copilot
Bottom line: The pick when you want a general assistant that does docs as one of many things.
How to pick
- Only need docstrings in VS Code: Mintlify Writer.
- Docs must stay in sync with code across a team: Swimm.
- Inherit an undocumented repo, need a README today: DocuWriter.ai.
- Code must not leave your machine: Continue.dev or Aider with a local model.
- Live in the terminal: Aider.
- Willing to switch editors: Cursor.
- Already pay for Copilot: stay on Copilot.
FAQ
Can an AI generate accurate docs for legacy code?
Usually, if the code is well-written. Poorly-named functions and complex control flow lead to hallucinated docs. Always review AI-generated docstrings before shipping.
Which of these run offline?
Continue.dev and Aider both work against local models (Ollama, LM Studio). Everything else calls a hosted API.
Can I generate docs for a private codebase?
Yes. Mintlify, Swimm, DocuWriter, Cursor, and Copilot all offer enterprise plans with data-handling terms. For strict data locality, use Continue.dev or Aider with a local model.
Do these tools handle multiple languages in one repo?
Yes. Every pick in this list handles at least Python, JavaScript, TypeScript, Java, C#, Go, Rust, and Ruby. Rarer languages depend on how well the underlying model knows them.
Will regenerating docs overwrite my custom edits?
Swimm is designed to preserve human-edited sections. Others (Mintlify, DocuWriter) replace the block. Commit before regenerating and diff before merging.