alternate_email Email Address Extractor star

How It Works

The extractor scans your pasted text with a regular expression that looks for the shape local-part@domain — a sequence of allowed characters, an @ sign, then a domain with at least one dot, matching how email addresses are almost always written. Paste a scraped web page, an exported mailing list, or a long email thread, and every string matching that pattern is pulled out, deduplicated case-insensitively, sorted alphabetically, and listed one per line. This handles messy real-world input without any extra cleanup on your part: addresses mixed into surrounding sentences, embedded inside HTML attributes such as mailto: links, or scattered across dozens of paragraphs in a large document dump are all found the same way.

The regex used here is a simplified, practical approximation of RFC 5322 — the actual technical specification for what counts as a valid email address. That's a deliberate choice, not a shortcut born of laziness: writing a single regular expression that is fully RFC 5322-compliant, catching every technically valid address while never matching an invalid one, is close to impractical. A fully compliant pattern can run to thousands of characters and has to account for rare but legal edge cases — quoted local parts like "john doe"@example.com, or domains written as bracketed IP addresses like user@[192.168.1.1] — that essentially never appear in real-world text. Every practical extraction tool, this one included, trades that last fraction of a percent of theoretical coverage for a pattern that stays fast, readable and reliable on the 99%+ of addresses people actually write.

What to Know

• It matches format, not existence. An address can look perfectly valid and still bounce — the tool has no way to check if a mailbox is real, active, or accepting mail.
• Duplicates are merged case-insensitively. [email protected] and [email protected] are treated as the same address and listed once.
• Everything runs locally. The matching happens in your browser with JavaScript — no text is uploaded or stored anywhere.
• Edge cases can slip through. Obfuscated addresses (like "name [at] domain [dot] com", written to dodge scrapers) won't match, since they intentionally don't look like standard email syntax.
• It's built for real extraction tasks. Pulling contact addresses off a scraped page, cleaning up a pasted mailing list, or checking how many unique addresses are buried inside a long forwarded email thread are all typical uses.