An honest comparison of Legacy Doc-AI, Mintlify, Swimm, and GitHub Copilot.
Lots of tools claim to help with documentation. But they solve different problems — here's what each actually does and when to reach for it.
| Tool | Primary Use Case | Legacy Code Support | Cost Model |
|---|---|---|---|
| Legacy Doc-AI | Batch docstrings, stale detection, README generation | ✅ Built for it | Per repo (£39/month) |
| Mintlify | Modern API docs from code annotations | ⚠️ Needs modernization | Per user/team |
| Swimm | Living docs tied to code structure | ⚠️ Needs doc-in-code setup | Per user |
| GitHub Copilot | AI code assistant with docstring help | ⚠️ One-at-a-time only | Per user ($10-19/month) |
Scans your whole repo, finds undocumented functions, checks docstrings against code, and generates unified diffs for review.
Choose it when: You have legacy Python or JS repos needing batch generation, stale detection and diff review — and you're on a tight budget.
Not for: Real-time docs while you code. Public API docs. Teams wanting docs living in source files.
Generates beautiful, searchable API docs from modern frameworks (Express, FastAPI, Django REST) with type hints and docstrings. Great for public-facing docs.
Choose it when: You're documenting a public API. You have a modern codebase with consistent annotations. You need hosted docs pages with search and versioning.
Not for: Fixing legacy code in place. Batch processing thousands of undocumented functions. Tight budgets with per-seat pricing.
Write docs alongside code with special annotations; Swimm flags docs needing update when code changes. Designed for teams wanting docs to evolve with the codebase.
Choose it when: Your team writes docs in code. You want continuous sync between code and docs. You're willing to refactor existing code to include annotations.
Not for: Quick fixes for legacy repos. Teams that don't want to change how they write code. Small budgets—per-user pricing adds up.
Copilot is primarily a code assistant. It can write docstrings via chat, but one function at a time — no batch mode, no stale detection, no repo-wide context.
Choose it when: You're already using Copilot for coding. You need occasional docstring help. You have a small team where per-seat costs are manageable.
Not for: Documentation overhauls. Legacy repos with hundreds of undocumented functions. Budget-conscious teams where one person does the documentation work.
Facing a legacy repo with outdated or missing docs? Legacy Doc-AI is the most direct solution — it's built for that job. The others are great tools built for different jobs.
Copilot for daily coding. Mintlify for public APIs. Swimm for living docs. Legacy Doc-AI for getting old repos documented in one shot.