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Email Normalizer

Normalize an email address by lowercasing it, and optionally stripping Gmail-style dots and plus-tag segments, to help spot duplicate accounts.

Category: development
Use Case: Deduplicating a User Database, Testing Plus-Tag Email Filtering, Comparing Email Addresses for Equality
Privacy: 100% browser-based

johndoe@gmail.com

Removed a + tag segment

Removed dots (ignored by Gmail)

Recommended Settings

Pro Tips

  • Gmail (and Google Workspace) uniquely ignores dots anywhere in the local part - 'j.doe@gmail.com' and 'jdoe@gmail.com' deliver to the exact same inbox
  • Plus-tagging (like 'jdoe+shopping@gmail.com') is supported by most major providers as a way to filter or track where an email address was used, but the tag isn't part of the real address
  • Dot-stripping is applied only for Gmail and Google Workspace domains, since most other providers treat dots as meaningful characters
  • This is a heuristic based on well-documented provider behavior, not a live verification - always confirm against the specific provider's actual rules for critical deduplication logic

Most Popular

Most people normalize emails to detect duplicate sign-ups where a user registered twice using dots or a plus tag

When to Use This Tool

Deduplicating a User Database

Identify user records that are actually the same person using Gmail dot or plus-tag variations.

Testing Plus-Tag Email Filtering

See what a plus-tagged test email normalizes to, for setting up filtering rules.

Comparing Email Addresses for Equality

Check whether two differently formatted email addresses actually reach the same inbox.

Cleaning Up an Email List

Normalize a list of email addresses to a consistent, comparable format.

How It Works

1

Split the email into its local part (before @) and domain, and lowercase the domain

2

Optionally strip everything from a + onward in the local part, for providers known to support plus-tagging

3

Optionally remove dots from the local part specifically for Gmail and Google Workspace domains, which treat them as insignificant

100% Private

Files never leave your device. All processing happens locally in your browser.

Lightning Fast

Powered by Client-side email address normalization for optimal performance on modern browsers.

Open Source

Built with verified, open-source libraries. Fully transparent.

Frequently Asked Questions

Does every email provider ignore dots?

No, this behavior is specific to Gmail and Google Workspace. Most other providers, including Outlook and Yahoo, treat dots in the local part as significant, distinct characters.

Is plus-tagging supported everywhere?

Most major providers (Gmail, Outlook, Yahoo, iCloud, and others) support it, but it's not a universal email standard - some smaller providers may not honor plus-tags at all.

Can this guarantee two emails are duplicates?

It's a strong heuristic based on well-documented provider behavior, but for guaranteed deduplication, sending a verification email to both addresses is the only fully reliable method.

Is my email address sent anywhere?

No. All normalization happens locally in your browser.