Email Address Normalizer Online — Free
Runs 100% in your browser — your files never leave your device.
Equivalent addresses can look different because of case, whitespace, plus aliases, and provider-specific dot handling. Paste one email per line to normalize them consistently for comparison or deduplication, with invalid rows reported instead of silently discarded.
How it works
- 1
Paste emails one per line
- 2
Review normalized or invalid rows
- 3
Copy the cleaned list
About this tool
What normalization catches
The same mailbox arrives as many strings: Gmail ignores dots in its local part, plus-addressing appends tags, and casing is meaningless per the standards. The tool lowercases the domain, applies provider-specific rules, and produces one canonical form per mailbox.
The deduplication use case
Mailing lists, CRM imports, and sign-up deduplication all break when john.doe+promo@gmail.com and JOHND OE@gmail.com are counted as two people. Normalize before storing or comparing — the duplicates surface immediately, and your uniqueness checks become trustworthy.
Provider rules are not universal
Gmail ignores dots; most providers do not — first.last@other.com is a different mailbox there. Plus-addressing is a Gmail convention other services may treat literally. The tool applies the rules of the domain it sees, which is why the domain matters.
Frequently asked questions
Is normalizing safe for delivery?
The normalized form reaches the same mailbox for providers whose rules the tool applies. For unknown providers, the tool lowercases the domain and leaves the local part as written — the conservative choice.
Should I store normalized or original addresses?
Store the normalized form as the deduplication key and keep the original as display data if you correspond with it. Comparisons run on the key; replies can use either.
Why lowercasing?
Domain casing is meaningless per the standards, and most providers treat the local part case-insensitively too. Lowercasing both is the pragmatic deduplication convention.