Observed arrival · 2026-09-19
Your Email Validation Can Do Better
A practical developer reference and sandbox for testing modern email-validation rules.
○Open
⊠Login
$Paid
†Ads
✦Pretty
●Pro
◎Niche
◉Human
⚑Risk
ƒJS
- For
- Developers maintaining signup forms
- Worth noticing
- The sandbox compares HTML5 checks with pragmatic regex across plus-addressing, subdomains, newer TLDs, and malformed input.
Field notes
The sandbox separates native browser constraint validation from a stricter pragmatic regex, displaying local-part, domain, and TLD results for each test address. Presets exercise plus-addressing, subdomains, newer TLDs, and an obviously broken local part. The surrounding reference recommends lowercasing only the domain, converting internationalized domains to Punycode, and treating DNS and confirmation mail as later checks rather than folding everything into one regex.
Observed signals
Read the marks
Editorial observations of this landing page, not a rating.
○OpenPublic substance visible
✦PrettyNotable craft visible
●ProPolished or operationally mature
◎NicheUnusually specific use
One card from the complete issue