Gmail username rules checker: is this a valid Gmail name?
In short: Paste one or many Gmail usernames or addresses and see which break Google's format rules, with the reason for each. It checks the format, not whether the name is taken. Limit: Checks the format only. It never asks Google whether a name is taken.
A Gmail username rules checker tests a name against Google's format rules: 6 to 30 characters, letters, numbers and periods only, with no two periods in a row and no period at the start or end. Paste usernames or Gmail addresses and each row says valid or names the rule it breaks. It checks the format, not whether the name is taken.
Names that pass the format? See which Gmail addresses already exist.
Price: this tool is free. Checking a whole email list is from $9/mo, and the first 100 checks are free with Google, no card. Check your list free nowSee pricing
Sample result
jane_doe breaks Gmail's format: an underscore isn't allowed. janedoe2026 passes.
- Name
- jane_doe
- Problem
- Character not allowed
- Character
- _
What this means for you
A name that passes is allowed to exist. It may still be taken.
- Length, characters, periods
- Names the rule each breaks
- Valid names as addresses
- CSV out, nothing uploaded
- Gmail
- Rules
- CSV
By SimpleVerifier Team · Last updated · Runs in your browser; nothing you paste is sent to us
Have Gmail names that pass? See which already exist.
- Paste the usernames above to test their format, with a CSV of every row and the rule each broke.
- Upload or paste it at /verify. Every address gets a live mailbox check, and the first 100 email checks are free with a Google sign-in, no card.
How do I check whether a Gmail username is valid?
- Paste usernames or full Gmail addresses, one per line, or comma separated. A name without an @ is treated as @gmail.com.
- Press Check the names. Each is tested for length, allowed characters, repeated periods and periods at the edges.
- Read each row: Valid format, or the rule it breaks and the characters at fault.
- Download the CSV, then find out which of the valid-format names are already taken by checking the addresses.
Example
- You enter
- Seven names:
janedoe2026,jane_doe,.janedoe,jane..doe,jd,sam.lee.consultingandlee@outlook.com. - You get
- janedoe2026 and sam.lee.consulting: valid format. jane_doe: a character Gmail doesn't allow (_). .janedoe: starts or ends with a period. jane..doe: two periods in a row. jd: under 6 characters. lee@outlook.com: not a Gmail address, and under 6 characters.
- Limits
- Format only, 6 to 30 characters of letters, numbers and periods. It never asks Google whether a name is taken. Runs in your browser.
What are Gmail's username rules?
A Gmail username is 6 to 30 characters long and uses letters (a to z), numbers (0 to 9) and periods. Google's help says it can't contain an ampersand, equals sign, underscore, apostrophe, dash, plus sign, comma or brackets, can't have more than one period in a row, and can't start or end with a period. See Google's Gmail help.
The checker applies exactly those rules to the text. Capitals are ignored, as Gmail ignores them.
Does a valid format mean the name is free?
No. It means the name is allowed to exist. Gmail also ignores periods, so jane.doe and janedoe are the same inbox, and a name can be taken, held back or never reissued by Google. Only Google's sign-up page can confirm a name is available.
To see which valid-format names already exist as mailboxes, check the addresses. To reduce a list to one row per inbox, use the Gmail address normalizer.
Why did a name fail?
The row says which rule: too short, too long, a character Gmail doesn't allow (the character is named), two periods in a row, or a period at the start or end. A name that is a company or other provider address, such as jane@outlook.com, is marked as not a Gmail address.
Who uses this tool, and for what?
- Founders
- Test a shortlist of Gmail names before you try them at sign-up.
- Developers
- Check what a sign-up form should reject for a Gmail field.
- List owners
- Find Gmail addresses in an export that can't be valid.
What can’t this tool tell you?
- Checks the format only. It never asks Google whether a name is taken.
- Google can change its rules; its Gmail help page is the final word.
- Applies to the username, so +tags and other add-ons should be removed first.
Common questions
- How many characters can a Gmail username have?
- Between 6 and 30 characters. Names shorter or longer than that fail the format check.
- Can a Gmail username have an underscore or a dash?
- No. Google's rules allow letters, numbers and periods only. Underscores, dashes, plus signs and other symbols are not allowed in the username itself.
- Can a Gmail username start or end with a period?
- No, and it can't have two periods in a row.
- Does this check if the Gmail name is available?
- No. It tests the format only. A valid-format name can still be taken, and only Google's sign-up page can confirm a name is free.
- Is it free to use on a list of names?
- Yes. It runs in your browser with no account, and nothing is sent anywhere.
- Do periods count toward the length?
- This checker counts the name as typed, periods included. Google ignores periods when matching an inbox, and sign-up can judge a borderline name differently, so treat a name at 6 or 30 characters as worth confirming on Google's sign-up page.
Sources
A tidy list can still be full of dead addresses.
Extracting, deduplicating and syntax checks all work on the text of an address. None of them can tell whether the mailbox exists. Only the server that hosts it can answer that, through an SMTP check, and that is what the paid product does.
- Upload the cleaned file as it is: CSVs up to 100,000 rows
- A real SMTP mailbox check on every row, with catch-all detection
- Small list? Starter at $9/mo covers 2,500 emails a month, cancel anytime
Plans from $9 a month, cancel anytime, no contract. Sign in with Google and your first 100 email checks are free, no card. The free tools stay free either way.