Email Address Normalizer

Overview

Canonicalizes email addresses so that Gmail's equivalent forms collapse to one: dots in the local part are removed, plus-address suffixes are stripped, and everything is lowercased. Paste a list, one address per line, and see each normalized result with a note of what changed, plus total and unique counts.

How It Works

Paste addresses into the input area, one per line — the sample shows two spellings of the same Gmail account. Each address gets a result card: the original crossed out, the normalized form underneath, and a note recording which rules fired ('dots removed', 'plus stripped'). The header shows Total and Unique counts, so a mailing list's true size is visible at a glance. Lines without an @ are marked Invalid rather than guessed at, and the normalized output is click-to-copy.

Step-by-Step Usage Guide

1. Paste your addresses, one per line, into the input area.
2. Check each card's note to see whether dots, a plus-tag, or only case was normalized.
3. Read the Unique count for the true number of distinct Gmail-equivalent mailboxes.
4. Copy the normalized addresses for your list or database import.

Technical Specifications & Standards

The tool implements exactly the equivalences Gmail itself defines for consumer accounts: Google ignores dots in the local part of @gmail.com addresses, delivers plus-suffix tags (user+tag@gmail.com) to the base mailbox, and treats googlemail.com as an alias domain — so the tool strips dots and plus-tags only when the domain is gmail.com or googlemail.com, and otherwise merely lowercases. That scoping is the whole point: dots are significant characters for Outlook, Yahoo, iCloud and Google Workspace accounts, where john.doe and johndoe are genuinely different mailboxes, and stripping dots there would produce false duplicates. Lowercasing is safe for the domain half (DNS is case-insensitive) and matches mainstream practice for local parts, though RFC 5321 technically reserves case-sensitivity there. The dedupe count compares normalized results, so two visibly different Gmail spellings count once. Honest limits: no SMTP or MX validation happens — 'unique' means textually distinct after normalization, not deliverable — and providers that alias plus-tags but respect dots are not modelled.

Targeted Use Cases

• De-duplicating a sign-up or newsletter list where users registered the same Gmail in several dot placements.
• Investigating suspicious sign-ups that differ only by Gmail plus-tags — a common self-referral and trial-abuse pattern.
• Cleaning a CRM export before a migration so equivalent mailboxes merge instead of duplicating.
• Checking whether two addresses a user supplied across forms are actually the same inbox.

Notes & Gotchas

• Trust dot-stripping only for gmail.com and googlemail.com — this tool applies it there and nowhere else, correctly.
• Do not assume a normalized match means the same person; shared or family mailboxes make textually identical addresses legitimately shared.
• Keep the original address as the delivery target and use the normalized form only for comparison keys.
• Treat the Unique count as a lower bound on deliverability — it counts distinct spellings, not verified inboxes.

Frequently Asked Questions