Why your `[^<]+` regex is silently breaking on React SSR output

📰 Dev.to · GasPriceCheck

Learn how React's SSR output can break your regex patterns and how to fix it

intermediate Published 30 Apr 2026
Action Steps
  1. Identify potential regex patterns that may be affected by React's SSR output
  2. Use a regex tester to validate patterns against React's SSR output
  3. Update regex patterns to account for React's HTML comment insertion during hydration
  4. Test updated patterns to ensure they work correctly with React's SSR output
  5. Refactor code to handle edge cases where regex patterns may still fail
Who Needs to Know This

Developers working with React and regex for SSR scraping will benefit from this knowledge to avoid silent failures in their code

Key Insight

💡 React inserts an HTML comment during hydration that can break regex patterns, so you need to update your patterns to account for this

Share This
🚨 React's SSR output can silently break your regex patterns! 💡 Learn how to fix it
Read full article → ← Back to Reads