📖 Original article: GitHub Gist
By Mohamed Amine Ben Mallessa — Lead Dev at Sollea AI
The challenge
Generate customized vector PDF posters and high-res PNG images server-side on the fly. No fat client, no browser UI, no paid SaaS.
The solution? Playwright (headless Chromium) + versioned HTML templates.
How it works
Form → HTML template + postMessage → Playwright headless → A4 vector PDF + 300 DPI PNG
The template: a self-contained HTML file with inline CSS and SVG. No external dependencies, no font loading, no network requests.
The render: Playwright opens the template, injects data via JavaScript, exports as PDF (1 page, vector, A4) and PNG (300 DPI, 2480×3508px).
The speed: ~3.5 seconds per document. Fully reproducible.
Why it beats wkhtmltopdf or Puppeteer
| Tool | Reliability | Vector | Size | Ease of use |
|---|---|---|---|---|
| wkhtmltopdf | ⚠️ CSS issues | ✅ | ❌ Unmaintained | |
| Puppeteer | ✅ | ✅ | ✅ | ⚠️ Heavy |
| Playwright | ✅✅ | ✅✅ | ✅✅ | ✅✅ |
Playwright handles fonts, viewport, headless mode natively, and integrates perfectly with FastAPI.
The trick
One HTML template = live preview in the browser AND final PDF/PNG render. No duplicate code, no preview/production divergence.
postMessage({ type: "setState", state: formData }) → the template updates. Whether inside a frontend iframe or Playwright's headless Chromium.
What we gained
- Zero subscription cost (no Canva, no Adobe)
- 3.5s generation time
- Perfect vector PDF (no pixelation)
- Print-ready PNG
- Templates versioned in Git
- New format = one folder
Originally published on GitHub Gist.
Mohamed Amine Ben Mallessa — Lead Dev at Sollea AI
🔗 Sollea AI · GitHub · LinkedIn
playwright #fastapi #pdfgeneration #htmltemplates #opensource #python #webdev
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Sollea AI — Full-stack development, AI automation, custom solutions.
🔗 Sollea AI · GitHub · LinkedIn
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