Playwright — when JS rendering is required

If a page won't show its content without JS, you need a real browser. Playwright is the modern default:

- Faster than Selenium (modern protocol, less polling)
- Auto-waits — fewer flaky 'element not found' errors
- One API across Chromium / Firefox / WebKit
- Native async support

Selenium still wins on legacy ecosystem and some IE/edge cases. For new projects in 2026 — Playwright.

Default to headed (visible browser) when developing. You see what's happening. Bug fixed in minutes.

Switch to headless for production / scheduled runs. Faster, less RAM.

Playwright trick: page.pause() opens DevTools paused at that line. Step through the script interactively. Saves hours of 'why doesn't this selector work' guessing.

From install to scraping in 20 lines. Use playwright codegen to record actions and emit Python — way faster than reading docs.

Don't hand-write selectors. Run:

playwright codegen https://target.com

A browser opens; click around; Playwright records every action and emits Python. Copy. Paste. Edit minor parts.

For scraping, this gets you 80% there in minutes. Combine with Playwright's locator selectors (text=, role=) — they're more robust than CSS / XPath.

Day 79 done.

- Playwright > Selenium for new code
- Headed for dev, headless for prod
- 20-line async script
- codegen records for you

Tomorrow (Day 80): scheduling. cron, APScheduler, Airflow — pick by ops fit.