Source: https://seerepo.com/compare/calcom/cal.diy/vs/Stirling-Tools/Stirling-PDF
Markdown source: https://seerepo.com/compare/calcom/cal.diy/vs/Stirling-Tools/Stirling-PDF.md
Description: cal.diy and Stirling-PDF share 4 technologies: React, Postgres, PostHog, and Stripe. Both are written in TypeScript.

# cal.diy vs Stirling-PDF

cal.diy and Stirling-PDF share 4 technologies: React, Postgres, PostHog, and Stripe. Both are written in TypeScript.

- [calcom/cal.diy](https://seerepo.com/r/calcom/cal.diy): Scheduling infrastructure for absolutely everyone.
- [Stirling-Tools/Stirling-PDF](https://seerepo.com/r/Stirling-Tools/Stirling-PDF): #1 PDF Application on GitHub that lets you edit PDFs on any device anywhere

## What they share and what sets them apart

- In common: React, Postgres, PostHog, Stripe
- Only in cal.diy: Next.js, Redis, Sentry, Google
- Only in Stirling-PDF: Vite, FastAPI, Spring, Supabase, AWS S3

## Side by side

| | cal.diy | Stirling-PDF |
|---|---|---|
| Size | 554,251 lines written, 4,310 code files | 1,114,394 lines written, 4,302 code files |
| Who writes it | 6.3% of its commits signed by AI. With Devin, Claude Code, CodeRabbit, Cursor, and GitHub Copilot | 2.1% of its commits signed by AI. With GitHub Copilot, Claude Code, and Codex |
| Activity | Last push October 27, 2026, 16,059 commits, 49,471 stars | Last push October 29, 2026, 5,694 commits, 95,274 stars |
| Tests | 641 test files. 14.7% of its code files have a test that imports them | 2,014 test files. 48.3% of its code files have a test that imports them |

- Size: Lines written by people and agents, without generated ones; code files, without tests.
- Who writes it: A commit counts as AI's when it carries its signature: a Co-Authored-By line, its author name or the merge of its branch.
- Activity: From GitHub and its history, on the day SeeRepo read it.
- Tests: The files that test the code, and the share of code files a test imports.

## Frequently asked questions

### Which is bigger, cal.diy or Stirling-PDF?

Stirling-PDF, with 1,114,394 lines written in 4,302 code files; cal.diy has 554,251 in 4,310.

The proof: [Stirling-Tools/Stirling-PDF's code at commit 96ee014](https://github.com/Stirling-Tools/Stirling-PDF/tree/96ee014b99a490822e9b9ea427afd13d76f9e5d4)

### Which has more GitHub stars, cal.diy or Stirling-PDF?

Stirling-PDF, with 95,274 stars; cal.diy has 49,471.

The proof: [Stirling-Tools/Stirling-PDF on GitHub](https://github.com/Stirling-Tools/Stirling-PDF)

### Which has more tests, cal.diy or Stirling-PDF?

Stirling-PDF, with 2,014 test files; cal.diy has 641.

The proof: [Stirling-Tools/Stirling-PDF's code at commit 96ee014](https://github.com/Stirling-Tools/Stirling-PDF/tree/96ee014b99a490822e9b9ea427afd13d76f9e5d4)

### Which was updated more recently, cal.diy or Stirling-PDF?

Stirling-PDF: its last push was on October 29, 2026, and cal.diy's on October 27, 2026.

The proof: [Stirling-Tools/Stirling-PDF's commits on GitHub](https://github.com/Stirling-Tools/Stirling-PDF/commits)

### Which has more commits signed by AI, cal.diy or Stirling-PDF?

cal.diy: an AI signed 6.3% of its commits, with Devin, Claude Code, CodeRabbit, Cursor, and GitHub Copilot; in Stirling-PDF, 2.1%.

The proof: [the commits each tool signed in calcom/cal.diy](https://seerepo.com/r/calcom/cal.diy/ai)

## Sources

- calcom/cal.diy: Read on October 28, 2026, at commit 56da01b (https://github.com/calcom/cal.diy/tree/56da01b4b1664894b784aca636eccab0c56cc141)
- Stirling-Tools/Stirling-PDF: Read on October 29, 2026, at commit 96ee014 (https://github.com/Stirling-Tools/Stirling-PDF/tree/96ee014b99a490822e9b9ea427afd13d76f9e5d4)

## What is your repo built with?

Any public repo, with no account: https://seerepo.com/r/owner/repo/built, with the owner and name it has on GitHub.